CLIMATE

• biometeorology : that branch of ecology which deals with the effects on living organisms of the extraorganic aspects of the physical environment (such as temperature, humidity, barometric pressure, rate of air flow, and air ionization). It considers not only the natural atmosphere but also artificially created atmospheres such as those to be found in buildings and shelters, and in closed ecological systems, such as satellites and submarines.
• meteorotropism : the response to influence by meteorological factors noted in certain biological events, such as sudden death, attacks of angina, joint pain, insomnia, and traffic accidents.
• meteoropathology : the pathology of conditions caused by atmospheric conditions.
• meteoropathy : any disorder due to conditions of climate
At the distance of the Earth from the Sun, solar irradiance is 1,360 W ^. m² :
• 48% visible light
• 45% infrared (IR)
• 7% ultraviolet (UV)
Most radiation is reflected as infrared (IR), which can be absorbed by CO₂ in the atmosphere.
• upwelling : the process by which water rises from a lower to a higher depth, usually as a result of divergence and offshore currents. It influences climate by bringing colder, more nutrient-rich water to the surface. This is a vital factor of the El Niño : a warming of the Pacific Ocean currents along the coasts of Peru and Ecuador near the Equator that is generally associated with dramatic changes or a shift in the weather patterns of the region. A major El Niño event generally occurs every 3 to 7 years and is associated with changes in the weather patterns worldwide including hurricane
• acid rains : lakes and waterways in North America are struggling to recover from the effects of acid rain, despite reduced emissions of the pollutants that cause it. Without further cuts, it could be millennia before the worst-affected sites recover, say environmentalists. Although the 1990 US Clean Air Act has reduced acid rain in northeastern North America, many lakes in eastern Canada are still beyond their critical load - the amount of acidification that harms the organisms living there, researchers told a meeting of ecologists in Montreal. Acid rain is caused largely by sulphur dioxide and oxides of nitrogen emitted by industrial activities such as coal burning. The gases dissolve in rainwater to form acids. Much of this industry is based in the USA, but the weather exports pollution north of the border. 50-70% of Canada's acid rain comes from the USA, while only 2-10% of America's pollution in this area comes from Canada. The Clean Air Act reduced US sulphur dioxide emissions from 16 million tonnes a year in the 1980s to 11 million tonnes in 2000. Rain is less acidic, but Ontario's lakes are not recovering. Many of the province's 31,000 small lakes have a pH value of about 5, making them dangerously acidic for fish and plants. We've had 20 years of reductions and things still haven't got better. That's going to annoy a lot of people; reductions are expensive. The soil around these lakes has simply been overburdened. Hydrogen ions formed when sulphates and nitrates dissolve in the rainwater, are generally buffered by calcium ions from the soil, curbing acidity. But so much acid rain has fallen that there is not enough calcium available to do this. It may take thousands of years for the soils to recover. Many acid-damaged soils in Europe are treated with lime to replace lost calcium. But this would be expensive to do in Canada's vast wilderness, and harmful if overdone. Another option might be to burn trees to release stored calcium, although this has never been tested. The only practical solution is to cut industrial emissions further. The lakes' plight is a reminder that it often takes longer to recover from pollution than it did to pollute. Many species find it harder to return to ecosystems disturbed by acidification. Lakes are resilient, but the timeline of recovery is longer than we expected. The situation also shows that the Canada-US Air Quality agreement, which aims to control levels of atmospheric pollutants across the countries' border, is still a work in progress. Further cooperation to cut emissions is likely to be necessary.

Web resources : Emissions trading on Wikipedia
• greenhouse effect : the process by which atmospheric gases, expecially CO₂, NO₂, CH₄ and chlorofluorocarbons (CFC), block the escape of heat from the atmosphere, and thereby warm the surface of the Earth. It's hard to work out which comes first (a rise in CO₂ or a slight warming) because even a slight temperature hike increases atmospheric CO₂, through its effects on forests and oceans. A subtle shift in the Earth's orbit around the Sun can trigger a minute amount of warming, but you need CO₂ to amplify the effect. There is also a greenhouse effect on sea-level air pressure.

Prevention :
• new cars are usually fitted with catalytic converters, which burn up most of the unreacted hydrocarbon fuel in exhaust gases and turn it into CO₂. But one of the big problems in making cars cleaner is how to prevent hydrocarbons polluting the environment while the catalytic converters warm up. Up to 80% of the hydrocarbons that make it into the atmosphere are emitted from vehicles during the 1-2' that catalytic converters take to get going after a cold start. So the hydrocarbons need to be trapped until the converter has reached its operating temperature, typically 170-200°C. SSZ-33 is a zeolite : a crystal made from silicon, aluminium and oxygen that looks, at the atomic scale, like Swiss cheese. The atoms in zeolites are linked into rings that form a 3D framework riddled with tiny pores and channels. These channels can hold vast quantities of gases and dramatically clean up exhaust emissions by trapping pollutants for the few minutes after the engine has been started. Zeolites have been investigated as hydrocarbon traps for vehicles before, and one of the promising candidates was a material called zeolite beta. But the pore network of zeolite beta tends to fall apart in moist air at high temperatures, which means the material loses its grip on the hydrocarbons. Zeolite SSZ-33 can hold 30% more hydrocarbons than zeolite beta, and it does not break down so readily when it is subjected to the kinds of high temperatures (around 800°C) that can be reached inside vehicle exhaust systems^ref.
• the age-old household tip that lemon juice makes for a great cleaning agent has found new use in the garage. Researchers have found that a simple wash of citric acid can spruce up exhausted catalytic converters in diesel-powered cars, renewing their pollution-busting properties. In diesel engines, catalytic converters contain a honeycomb of platinum that cleans up exhaust gases by turning poisonous carbon monoxide and unburned hydrocarbons into more benign carbon dioxide. This breaks down molecules that could contribute to smog. But sulphur in the fuel and phosphorus from anti-wear oil additives can gum up a converter and prevent it from working. Researchers have tried various methods to clean them out in the past, mostly involving strong acids. But while these often do a good job of wiping away the gunk, they also tend to eat away at the valuable platinum. A dilute solution of citric acid can wash out the catalyst killers without damaging the platinum. When tested on a simulated stream of exhaust gases, the cleaned-up catalysts were as good as new. The citric acid - which was produced industrially rather than by squeezing lemons - removed up to 82% of the phosphorus and about 90% of the sulphur from a catalyst that had been used for 48,000 km of driving in a diesel-fuelled car. The wash cycle took 6 hours at 80 °C. Removing sulphur and phosphorus in this way is a very positive step. The average vehicle runs for roughly 240,000 km, and catalytic converters are supposed to last this course. But some researchers have claimed that up to 90% of catalysts fail before they reach 80,000 km. Regenerating them periodically could help to reduce emission pollution. Cars built in the USA already have on-board emissions monitoring, which should alert the driver when the catalyst starts to fail. Similar guidelines are expected to come into force in Europe within the next few years. At present, many used catalytic converters are recycled to extract the expensive platinum metal. But this energy-intensive process wastes the rest of the converter. Reactivation would be much more environmentally friendly. But it may be more expensive. The only people who would find it economically feasible to clean their converters would probably be those with fleets of diesel trucks that can each cover 2 million km in their lifetime. With more stringent emissions monitoring on the horizon, it would make good sense for these engines to get a regular spring clean. These are big, valuable devices, and replacing them can cost as much as replacing an engine

Web resources : Institute of Catalysis and Petrochemistry
• many methods have been put forward to curb emissions of CO₂, such as :
• growing plantations of trees to soak up CO₂ : trees don't seem to grow any faster when given an exrtra dose of CO₂, shattering the widespread belief that rising concentrations of CO₂ may be kept partly in check by blossoming plant growth. Some researchers have suggested that as CO₂ levels rise, plants will thrive on the gas, which they use to photosynthesize; trees may be prompted to grow faster and grasses to spread, for example, which would help to suck up some of the excess carbon dioxide. But a study of a large patch of deciduous forest near Basel in Switzerland, which has been artificially sprayed with excess carbon dioxide for years, has shown no such increase in growth.  Some scientists and politicians cling to the idea that a CO₂-rich future might favour the greening of planet Earth. It's time to disillusion them. What remains is the greenhouse gas effect. The team artificially created sustained carbon-dioxide-rich conditions in the patch measuring 500 m² by spraying pure carbon dioxide into the canopy of about a dozen mature deciduous trees. Each day during the six-month annual growth season, the scientists sprayed two tons of extra CO₂, from industrial waste, into the canopy. This simulated an atmosphere loaded with about 530 ppm of CO₂, roughly 1.5 times what exists today. But after four years the researchers found no signs of enhanced biomass growth in stems or leaves^ref. The trees had merely pumped the extra carbon through their bodies, quickly re-releasing it through root and soil microbe respiration; there was no lasting effect on growth and photosynthesis. To rule out confounding factors, the team determined the extent of natural variations in tree growth, with the help of the tree-ring record, during a 2-year pre-treatment study. They were also careful to select a multi-species forest in the middle of its life that is widely undisturbed by human interference. Given the limited duration and extent of the experiment, it is too early to say whether the results can be generalized. The team was unable to include conifers in their study, for example. It also remains to be seen whether a fraction of all this extra carbon might be stored in the soil rather than in the trees. If so, there may still be cause to think that forests will suck up more carbon dioxide in a warming world. This CO₂ fertilization technique should be applied in 3-4 large experiments in different vegetation zones, from boreal forests to tropical rain forests, with an international board of scientists overseeing the studies. This is the only way to settle the fundamental question of how changes in the air affect the bulk of the Earth's biomass. The results of some previous small-scale experiments have suggested that carbon-dioxide enrichment does stimulate plant growth. A small biomass increase in the Amazon rain forest over the past 25 years was found (Malhi Y The Carbon Balance of Forest Biomes (eds Griffiths, H. & Jarvis, P.G.) (Taylor and Francis, Oxford).2005)). How much of this can be attributed to increased CO₂ is unknown, however. The Swiss study is fantastic in terms of methodology and species mix, but it is too early to come to general conclusions. A similar experiment in tropical forests should definitely become a top priority.
• stop ploughing farm fields, which would slow the release of CO₂ through the normal bacterial breakdown of plant waste. If farmers stopped tilling all the cropland in the country, and either switched to alternative farming techniques or left land fallow, carbon emissions would drop by < 4%. In order to hit the 10% target, at least one third of that land would have to be planted with forests to sop up CO₂, which would reduce the food supply and have unknown additional consequences for the environment
• the USA could, however, achieve a 10% emissions cut by doubling the fuel efficiency of all cars and sports utility vehicles (SUVs) : this could be done by switching to existing hybrid electric vehicles, which run partly on electricity. Although there is a price to pay for cleaner cars - hybrid vehicles currently cost a few thousand dollars more than conventional gas-guzzlers - the exercise highlights how small changes in existing technology could make considerable dents in USA emissions. Additional price subsidies for consumers, or a hike in gasoline prices, could encourage drivers to switch to hybrid vehicles. Showing that cars could make such a big difference is really, really important. The USA pumps out more greenhouse gases than any other country in the world. The Bush administration focuses instead on voluntary emission cuts and longer-term improvements in fuel efficiency, such as moves towards hydrogen-powered vehicles and nuclear energy. Even if USA did adopt drastic steps to clean up, the country would still struggle to achieve cuts equivalent to those required of industrialized countries by the Kyoto agreement: a reduction of at least 5% relative to 1990 levels by 2012. This equates to a 30% cutback from today's levels. No single policy or technology switch can make such a big dent in USA pollution - but combined, they might make a real difference. SUVs make an entirely unnecessary contribution to global warming and there's a huge and unacknowledged health crisis which results from vehicle emissions. According to WHO, vehicle emissions are responsible for tens of thousands of premature deaths in western Europe alone each year. The agency also ascribes around 150,000 deaths globally each year to climate change. Because SUVs are generally heavier than conventional cars, they need bigger engines, which tend to produce more CO₂. In the UK, for example, a Land Rover 4.4 V8 emits 389 g of CO₂ per km travelled - more than twice that of a Saab 93 1.8i. Chrysler-Jeep's Grand Cherokee produces 370 g per km travelled - a PT Cruiser, from the same manufacturer, just 212. But if you look at things like diesel buses, old Routemaster buses, diesel taxis, any diesel HGV, they kick out 10 times more toxins than the modern 4x4 with its anti-smog equipment and catalytic convertors.
Effects :
• global warming :

History and trends :
• the extent of climate variability during the current interglacial period, the Holocene, is still debated. Temperature records derived from central Greenland ice cores show one significant temperature anomaly between 8,200 and 8,100 years ago, which is often attributed to a meltwater outflow into the North Atlantic Ocean and a slowdown of North Atlantic Deep Water formation—this anomaly provides an opportunity to study such processes with relevance to present-day freshening of the North Atlantic. Anomalies in climate proxy records from locations around the globe are often correlated with this sharp event in Greenland. But the anomalies in many of these records span 400 to 600 years, start from about 8,600 years ago and form part of a repeating pattern within the Holocene. More sudden climate changes around 8,200 years ago appear superimposed on this longer-term cooling. The compounded nature of the signals implies that far-field climate anomalies around 8,200 years ago cannot be used in a straightforward manner to assess the impact of a slowdown of North Atlantic Deep Water formation, and the geographical extent of the rapid cooling event 8,200 years ago remains to be determined^ref.
• Australia's large prehistoric animals (megafauna) were as bizarre as anything that lives there today. King of them all was the marsupial lion, a 130-kg meat-eater who lived alongside giant kangaroos, huge lizards called goannas, and Diprotodon, which resembled a 3-tonne wombat. After the arrival of humans on the continent, at least 45,000 years ago, these weird and wonderful creatures began to die out. Experts blamed the colonizers, arguing that they launched a hunting 'blitzkrieg' that wiped out the megafauna within a few generations. But the animals may have survived for a lot longer than people thought : excavations seem to show that man and beast lived side by side for as long as 15,000 years. She suspects that as Australia approached the most recent ice age, the growing cold and aridity turned much of the continent into a place where these large animals simply could not survive. Although man probably did hunt the large animals, the fact that they survived for so long argues against the blitzkrieg model, she adds. There's this image of spear-wielding hordes hacking through startled megafauna, but there's a range of stone tools, for butchery, woodworking, grinding. There's no evidence of a toolkit with specialized hunting gear. Animal bones collected from a 10-metre-deep section of earth at Cuddie Springs, New South Wales. They focused on bones from 4 layers: 2 with evidence of human settlement, such as stone tools, and 2 deeper ones with no evidence of tools. The bones were dated by measuring the amounts of radioactive elements, such as uranium and thorium, that remained in the bones. The various animal carcasses in each level would indeed have lived cheek by jowl with humans as recently as 30,000 years ago. Proponents of the blitzkreig model had previously argued that the dating of the Cuddie Springs material was not certain, but their research clears up the matter. Well-preserved bones at other sites have been very hard to find, probably because they are too dry, whereas Cuddie Springs is the site of an old lake bed. Climate change may have killed off many of Australia's animals. By looking at smaller animal bones from the Darling Downs in Queensland, they show that their disappearance seems to have coincided with increasing dryness. But the matter is not settled yet, particularly as the timing of humans' first foray into Australia has still not been agreed. Fossil evidence from Lake Mungo in New South Wales suggests that they may have arrived 60,000 years ago. And it is possible that they hastened the megafauna's demise by burning habitats to make way for primitive agriculture. Field remains convinced, however, that it was climate that drove the animals to their death : the arid zone grew to encompass 70% of the continent by 30,000 years ago. There would have been very few opportunities once it got dryer.
• a brief period of warming at the end of the Palaeocene epoch was probably sparked by a catastrophic release of greenhouse gases, and seems to have triggered a mass extinction unprecedented on the planet's more recent past. The warming episode was first noticed in the 1980s by oceanographers analysing Antarctic sediment cores. Around the world, temperatures in an already warm climate shot up by a few degrees, a rise that was probably caused by the release of millions of tons of methane gas from the sea floor or a series of huge volcanic eruptions. As a result, the oceans heated up so fast that many species were unable to adjust and became extinct. In some parts of the planet, the warming seems to have been even more pronounced : 55-million-year-old sediment cores from > 400 m beneath the sea floor, in waters 1,300 m deep, around 200 km south of the North Pole suggest that the Arctic Ocean temporarily warmed to around 20°C. The researchers also found evidence that many bottom-dwelling species that had been living in the Arctic Ocean before the warming completely disappeared with its onset.

Web resources :
• Integrated Ocean Drilling Program (IODP) : Expedition web site
• European Consortium for Ocean Research Drilling (ECORD)
• humans began altering the climate 8,000 years ago, long before the industrial revolution : massive clearance and irrigation for agriculture released huge amounts greenhouse gases into the atmosphere. By the time the industrial revolution got under way, we had already raised the global temperature by an average of 0.8ºC and by as much as 2 ºC at high latitudes - enough to deflect an impending ice age. Today's winters would be as much as 7°C at high latitudes if it were not for the pre-industrial input of greenhouse gases. Concentrations of greenhouse gases in the atmosphere fluctuate cyclically : small changes in Earth's orbit affect the amount of solar radiation reaching our planet. Records of these cycles in ice cores dating back 400,000 years suggest that CO₂ and CH₄ should have been declining steadily for at least the past 10,000 years. Instead, CO₂ has been rising for 8,000 years and CH₄ for 5,000. The idea is likely to spark debate among climate scientists, but at least one sceptic is already changing his mind. Increased solar radiation every 22,000 years has been linked to stronger monsoons, which in turn lead to more wetlands. Decay of wetland vegetation releases more CH₄ into the atmosphere. Atmospheric CH₄ reached its most recent peak 11,000 years ago and should since have been dropping along with solar radiation. The reversal of this natural trend 5,000 years ago was caused by the advent of irrigation of rice crops and tending of large herds of livestock in Asia. A similar story could explain the unexpected change in the CO₂ cycle. Every 100,000 years, CO₂ has risen sharply and then declined steadily for at least 15,000 years. But following the last peak 10,000 years ago, levels dropped slowly for only 2,000 years, then began increasing again. This change coincides with the beginning of major deforestation for agriculture in Eurasia 8,000 years ago.
• to work out the planet's temperature during the past few hundred years, researchers often look at the width and density of annual rings in trees or the growth of corals. Such temperature indicators, known as proxies, are then used to construct average global temperatures. But this method could be tainted by a systematic error, and consequently researchers might have underestimated the size of temperature fluctuations from Roman times until the 19th century, by a factor > 2. Temperature fluctuations in a reconstruction were smaller than in the original climate model^ref. Any attempts to reconstruct the global climate from real proxies, such as tree rings, corals, ice cores and historical weather records might similarly underestimate temperature changes. Scientists currently use a combination of proxies and written records from the twentieth century to estimate past climate change and the probable future course of the current warming trend. The mean global temperature has increased by 0.6ºC during the past century, with particularly pronounced warming in the last 20 years. At present researchers think that this warming is different from anything that has happened on our planet in the past 10,000 years. The study does challenge how much of the warming, particularly prior to 1980, is a result of natural fluctuations in temperature. The most widely cited proxy-based reconstructions of historic climate variability was carried out by Michael Mann^ref.
• Michael Crichton's latest novel, State of Fear (published by HarperCollins on 7 Dec 2004) is simply wrong in data^{ref1, ref2, ref3}. No one pointed out that the global mean temperature rise since 1900 is in fact about 0.8 °C and that this is more than has been observed at any time in the past one thousand years. And the temporary reversal of the trend during 1940-70 is fully accounted for by climate models, as the IPCC report shows very clearly. The cooling seems to be largely the result of sulphur pollution, which created atmospheric sulphate aerosols that temporarily masked the greenhouse-gas-induced warming by reflecting sunlight and altering cloud cover.
• the release of the gases, which include CO₂, CH₄ and NO₂, fell by 0.5% in the European Union (EU) from 2001 to 2002^ref. Under the terms of the December 1997 Kyoto Protocol, European countries have pledged to reduce their greenhouse-gas emissions by 8% by 2012, relative to 1990 levels. That had seemed a distant target before the latest figures were released. After initial good progress in the wake of the agreement, emissions had risen steadily since 2000. The report also shows that Europe is still not quite on track to meet its Kyoto target. Greenhouse emissions for 2002 are just 2.9% below 1990 figures. And CO₂ releases, which account for more than 80% of total emissions, are actually higher. The latest reduction in overall greenhouse-gas releases are mainly due to cuts in methane and nitrogen dioxide through better waste management and a shift from coal- to gas-fired power stations : the trend has been spearheaded by Britain and Germany, which together are responsible for about 40% of Western Europe's emission. Europe's modest progress should also set an example to the USA, Australia and Russia, neither of which has yet signed the Kyoto pledge. Since the USA backed out of the environmental treaty, Russian participation has been the only way that it can come into force. In order to become legally binding, the pact has to be ratified by a set of countries that together were responsible for at least 55% of the world's 1990 carbon emissions. Russia accounted for 17% of global emissions in 1990. Combined with the 44.2% of 1990 emissions that are accounted for by industrialized nations who have already ratified the treaty, this would fulfil the requirements for the agreement to come into force. All participating industrialized countries would then be legally obliged to meet their pledge to reduce greenhouse gas by at least 5% relative to 1990 levels by 2012. Climate researchers agree that to make a real difference to climate change, greenhouse-gas levels need to be cut by 60%. Under the terms of the current agreement, developing countries will not be penalized at all, and industrialized nations must simply make up any target shortfall during the second phase of the treaty, in 2012-16, plus a 30% penalty. Delegates from nearly 200 countries, as well as United Nations officials and lobbyists, are meeting in Buenos Aires over 6-17 December for the tenth session of the Conference of Parties (COP) to the UN Framework Convention on Climate Change. Together they are discussing the finer details of this convention, which came into force 10 years ago, and the Kyoto Protocol, which will take effect on 16 February 2005. Those delegates who have signed the protocol are particularly keen to hash out post-Kyoto strategies, including how developing countries might become more involved in adaptation and mitigation strategies. But the US delegation has declined to enter into discussions about events after 2012, when the terms of the Kyoto Protocol expire, even while most countries continue to court US support in controlling emissions. At the same time, the board of the Clean Development Mechanism (CDM), an arm of the Kyoto Protocol, has said it could close its doors on countries not party to the protocol, including the United States. Officially, observer parties are allowed to attend such deliberations, except when confidential decisions are made. But there is some room for interpretation of this rule. The CDM meetings are quite small and bureaucratic, but the US delegates may be strategically trying to ensure that they aren't kept out of other Kyoto negotiations. Experts say the USA must be kept involved in climate talks in order to make real progress on emissions reductions. Former president Bill Clinton, who sent his vice-president to Kyoto meetings during his term and seemed little interested in the issue, set up a climate-change forum in New York on 6 Dec 2004. > 7 years after its inception, the Kyoto Protocol is finally up and running. From Wednesday 16 February 2005, countries throughout the world must make good their promise to cut greenhouse-gas emissions. The agreement, could not be enforced until it had been ratified by a set of industrialized countries that, in 1990, were responsible for at least 55% of global greenhouse-gas emissions. That threshold was reached by Russia's ratification in November 2004, which set off a 90-day countdown until the protocol could become law. Environmental ministers from around the world will today mark the culmination of this countdown with a ceremony centred on Kyoto in Japan, the treaty's birthplace. 35 developed countries now face the task of reducing overall greenhouse-gas emissions by 5.2%, relative to 1990 levels, before 2012. Each state has been given an individual target: Britain, for example, must curb its emissions by 12.5%; Japan must cut its own by 6%. Nations will attempt to meet their targets by improving the fuel-efficiency of power stations, manufacturing plants and transport. The protocol also allows industries to earn 'carbon credits' that can be used to offset any overshoot on the emissions targets set for them by national governments. These credits can be earned by investing in the United Nations Clean Development Mechanism, a scheme that funds the adoption of green technologies in developing countries. Alternatively, industries struggling to hit their targets can take advantage of trading schemes that harness international commodity markets to allow the buying and selling of carbon credits. The activation of the 141-nation treaty also cements the pariah status of the USA and Australia, which together account for > 25% of world greenhouse-gas emissions : they have declined to ratify the agreement, claiming that it will damage their economies. It now seems unlikely that either country will ever ratify the agreement : both countries' emissions have risen by > 10% since 1990, meaning that Kyoto's tight demands would now require their economies to turn on a dime. There are signs that efforts on a sub-federal level are afoot in the United States. Senators Joseph Lieberman (Democrat, Connecticut) and John McCain (Republican, Arizona) have tabled a bill that calls for an emission-credit trading scheme similar to that established this year by the European Union. The governments of California and of the New England states are investigating the possibility of implementing such 'cap-and-trade' schemes on a regional level. Just because the US administration is not moving on this, it doesn't mean there's monolithic inactiin. In a speech on 15 February 2005, former USA vice-president Al Gore criticized the "moral cowardice" of the Bush administration in declining to ratify the Kyoto Protocol.

Australia and 5 other nations have signed a pact that the Australian government has said is superior to the Kyoto Protocol. On 28 July 205, Australia, China, India, South Korea, Japan and the USA announced that they had signed an independent pact to help tackle climate change. But experts have criticized them for not adopting targets for emission reductions. The Asia-Pacific Partnership on Clean Development and Climate, which promotes using new technologies to reduce the amount of greenhouse gas in the atmosphere, has been worked out in secret by the parties involved, so its announcement has come as something of a surprise. Climate-policy experts say that although the aims of the pact are worthwhile, it contains no new financial commitments or targets. Australia and the United States are the only two developed nations not to ratify the Kyoto Protocol, and experts say the pact is likely to be used by them to deflect pressure to accept future versions of the protocol. They want to say 'Leave us alone, we're already doing something'. Talks about what to do when the protocol expires will begin in earnest in November. The Australian government is under pressure at home because of its anti-Kyoto stance. The opposition there has said that it would ratify Kyoto, so the government needs to be seen to be doing something. Experts caution that there isn't really anything new within the pact itself. Both the United States and Australia have long promoted technological solutions as the best way to tackle climate change. The United States already has bilateral technology cooperation agreements with all the countries involved. Energy experts say that new technologies, such as renewable energy systems and more efficient vehicles, are a vital part of climate-change measures. But they add that emission targets are the best way to act now. I don't see this announcement as a threat, but it reflects a way of thinking that could threaten effective action. Technology cooperation is being presented as an alternative to the hard issues of building incentives for energy efficiency and low-carbon technology investment by the private sector, which has to include regulating carbon emissions. The pact makes practical sense for all involved.  India, China and the United States all rely on coal as an energy source, so they have a mutual interest in technology that could make fuel more environmentally friendly. The pact could also give its three developed nations, Japan, the United States and Australia, better access to energy-technology markets in India, China and South Korea. These three developing countries will need such input if they agree to cut emissions in the future.
• activity on the international carbon-trading market has grown following the launch of the European Union's Emissions Trading Scheme on 1 Jan 2005. The volume of trading had already doubled in both November and December 2004. The idea of a carbon market is to allow industrial organizations such as power companies and factories to buy and sell the right to emit greenhouse gases such as CO₂. And companies have been trading in carbon emissions voluntarily since 1998. But 2005 has seen the advent of a Europe-wide scheme that will standardize the process and prepare the union for the forthcoming implementation of the Kyoto Protocol. The project is a step up from smaller US schemes and involves some 12,700 organizations in the union's 25 member states. Each state is given a national allocation of carbon credits, with the aim of cutting emissions by around 1% a year during the project's first phase, which runs until 2007. It then farms these out to individual companies. Traders can buy extra credits, giving them the right to exceed their emissions limit, or sell them if they are below their limit. Companies that fail to stay inside their limit face a fine of € 40 (US$52) for every tonne of excess CO₂ that they emit. The amount of activity on the market has grown exponentially in recent months as traders readied themselves for the European scheme. On 6 January, brokers oversaw deals involving some 600,000 tonnes of CO₂ emissions, say London-based brokers CO2e.com. And this daily total looks likely to grow steadily, as more traders join the market. Prices on the market have decreased since the end of December, however. The price of a tonne of CO₂ credit has fallen by about 1 €, from 8.5 to 7.65. This is likely to be a knock-on effect of other changes in the power sector, she explains, especially shifts in the coal market. Qureshi suspects that a drop in the use of coal has caused predicted CO₂ emission levels to drop, making carbon credits less valuable. Analysts will continue to watch the market's movements closely as more traders enter the fray. With the European scheme only a few days old, it is not yet clear whether the price fall is a genuine trend or whether the market will soon bounce back.

Web resources :
• Events to mark Kyoto introduction
• US EPA global emissions inventory
• Avoiding Dangerous Climate Change, a meeting organized by the UK government and the Exeter-based Met Office, attempted to assess the current and future state of climate change, and how to avert it. Many concluded that it is impossible to define "dangerous" climate change, as impacts vary wildly from place to place. Regardless, others hoped that one message would be clear : we don't really need more detail now, we already have enough information to make an educated guess on how we need to reduce emissions. Researchers agreed that the predictions about climate change made a decade ago are coming true. Thermal expansion of the oceans, acidification of water, increased air temperature leading to more storms; there is evidence for all this now. The Antarctic is one key area of concern : 5 years ago, most scientists were not concerned about Antarctica melting. But recent evidence shows that the Pine Island Glacier is eroding, and might unleash a mass of ice from the western half of the continent. If western Antarctica melts, it will raise sea levels by about 6 m. Others presented worries that were more familiar, but just as real: Greenland may melt; Africa may experience more drought; acidic oceans will imperil coral reefs; and ocean circulation in the Atlantic may shut down, freezing northern Europe. Several noted that we have the technology to prevent serious temperature rises, at the relatively moderate expense of < 4% less of the world's gross domestic product (GDP). The options include better energy efficiency, or capturing CO₂ as it is produced from power plants and burying it underground. David King, the UK government's chief scientist, told the meeting that he had spoken to oil companies about the possibility of pumping CO₂ into old oil wells in the North Sea. Socolow summarized what could be done. For carbon emissions to remain stable over the next 50 years we would need to reduce projected emissions in 2054 by 7 billion tonnes of carbon. 1 billion tonnes of cuts could be achieved by doubling the fuel efficiency of 2 billion cars, or by building 2 million 1-megawatt electric windmills, or even by doubling the electricity produced in nuclear power plants. All of these numbers carry a large amount of error. And scientists said that it was hard to work out what the atmospheric concentration of CO₂ would have to be to lead to a 2 °C warming on pre-industrial times. However, if one delays cuts for 10 years, we will need to double the rate at which we reduce emissions later, and that is a very expensive proposition. Increased snowfall over a large area of Antarctica is thickening the ice sheet and slowing the rise in sea level caused by melting ice. A satellite survey shows that between 1992 and 2003, the East Antarctic ice sheet gained about 45 billion tonnes of ice - enough to reduce the oceans' rise by 0.12 millimetres per year. The ice sheets that cover Antarctica's bedrock are several kilometres thick in places, and contain about 90% of the world's ice. But scientists fear that if they melt in substantial quantities, this will swell the oceans and cause devastation on islands and coastal lands. The Intergovernmental Panel on Climate Change (IPCC) has reported that sea level is currently rising at about 1.8 millimetres per year, largely through melting of the Greenland and Antarctic ice sheets as a result of global warming. But the panel also expected that climate change would trigger an increase in snowfall over the Antarctic continent, as increased evaporation from the oceans puts more moisture into the air. These effects have been predicted for a long time, it's just that no one has measured them before. Although the results of the satellite survey are in line with the predictions of global-warming models, the thickening of the ice sheet could still be explained by natural weather variability. The team used data from the European Space Agency's radar satellites ERS-1 and ERS-2, which measured changes in altitude over about 70% of Antarctica's interior - > 8.5 million square kilometres, roughly the same size as the USA. East Antarctica thickened at an average rate of about 1.8 centimetres per year over the time period studied. The region comprises about 75% of Antarctica's total land area - but as its ice is thicker, it carries about 85% of the total ice volume. It is the only large terrestrial ice body that is gaining mass rather than losing it. In contrast, smaller West Antarctica showed an overall thinning of 0.9 cm per year. The thickening of the eastern ice sheet should not be seen as a long-term protection against a rise in sea level. Glaciers in West Antarctica are accelerating, releasing more and more icebergs into the sea. And the Antarctic Peninsula, which stretches towards South America, now regularly hits temperatures above 0 °C in the summer, leading to direct melting of the ice there. What's more, snowfall over East Antarctica will not continue to increase indefinitely in a warming world. Conversely, every extra degree of temperature rise will continue to accelerate glaciers and cause more melting on the western side of Antarctica, swelling the world's oceans further. Antarctic melting may be responsible for up to a third of the overall sea-level rise. But the instruments on ERS-1 and 2 only work over very flat areas, and tend to lose track of the radar echo over steeper areas around the continent's coast, so a vital piece of the puzzle is still missing. And because Antarctica is so vast, it is also impossible to measure snowfall comprehensively on the ground. However, the European Space Agency satellite CryoSat, due to be launched late in 2005, should be able to make very accurate altitude measurements around the coast, providing evidence of exactly how much ice is being lost there. Only when scientists put all these measurements together will the full truth about Antarctica's ice become clear. This map (left) shows key areas of Antarctica, including the vast East Antarctic ice sheet. The image on the right shows which areas of the continent's ice are thickening (coloured yellow and red) and thinning (coloured blue).


The British Antarctic Survey has announced the result of its competition to design a new research base on the frozen continent. The winning proposal offers researchers the opportunity to live in elevated modules perched on skis. The station, which will weigh < 800 tonnes, will sit nearly 4 m above the snow, and is aerodynamically designed so that winds accelerate under it, sweeping loose snow away. As the overall snow level steadily rises, the building will be raised on extendable legs by a metre every year. Thanks to the skis, the station can also be towed across the ice. The structure will be built on the Brunt Ice Shelf, which flows some 400 m towards the sea each year. Initially positioned some 30 km inland, the building will need to be moved some time within the next 10 to 20 years. The station will replace the Halley V Research Station, the research base where the Antarctic ozone hole was first discovered. That building is now edging perilously close to the sea: scientists predict that a huge iceberg will break off from the shelf sometime around 2010, potentially taking the station with it. The replacement, a steel, timber and aluminium structure designed by Faber Maunsell and Hugh Broughton Architects, will hopefully make life easier in Antarctica's desolate climes. The building, which resembles a train of insects marching across the ice, features a central module containing recreation areas, flanked by modules for research and living quarters. The central module also features large, triple-glazed picture windows; researchers living at several of Antarctica's 82 existing stations have complained of depression brought on by living in dark, cramped quarters, often completely buried by snow. Much of the modules' structure will be prefabricated, meaning the modules will be quick and easy to assemble in the harsh Antarctic conditions. "From arriving at the site to getting a weatherproof base will take just 35 days. The station will also feature solar panels for summer use, along with the aviation fuel traditionally used to power remote buildings in freezing climates. Power requirements are far greater in summer, when the station will house a crew of 52 people, as opposed to winter, when just 16 (roughly half of them scientists) will live there. The station will also potentially be able to use other renewable energy sources, such as wind power, although current technologies are not yet up to the job. The conditions are so harsh that it's difficult to get robust enough equipment. We can't rely on it because the power is really life-critical. Construction on the station will begin in early 2007, and the first residents are due to move in late the following year. When they arrive, they will largely focus on making measurements of the snow and ice, and of the atmospheric and meteorological conditions. And the perpetually dark winter will offer a chance to study the southern aurora.Runners-up in the competition, organized in conjunction with the Royal Institute of British Architects, were designs featuring a "glowing translucent skin" and a building clad in a "puffer jacket" of insulating fabric pillows^ref.
Southern Hemisphere warming has surprisingly not led to increased snowfall over Antarctica during the past 50 years. If the findings are confirmed, this suggests that global sea-level rise might proceed faster than previously thought. Average surface temperatures in the Southern Hemisphere have increased by roughly 0.5 °C since the 1950s. Climate models predict that the warming and increased evaporation should result in more snowfall over Antarctica, because the warmer air transported southwards would carry more moisture. But a reconstruction of the Antarctic precipitation record suggests that, at least in the past, this has not been the case. Weather observations near the poles are scarce and often unreliable, which makes it difficult to determine past precipitation. Andrew Monaghan, a meteorologist at Ohio State University's Byrd Polar Research Center, and his team used a combination of ice-core and model data to fill the large voids between the few stations. The new results double the length of the snowfall record available for Antarctica. The 'weather hindcast' reveals that snowfall is very variable from 1 year or decade to the next^ref. Within this noise, the team could not make out a statistically significant upward trend in the total amount of snowfall. If warming does not result in more snowfall, this seems to suggest that the increased input of moist air is outweighed by changes in storm tracks and wind patterns, resulting in less precipitation. Unfortunately 50 years are not enough to figure out which component will eventually win out. It could go either way. Antarctica harbours 90% of the world's ice; if the 30 million km³ of ice held in its sheets were to melt, the global sea level would rise by > 60 metres, flooding vast stretches of densely populated coasts around the globe. At present, the global sea level rises by around 3 mm/yr. The rate could increase if glaciers in Antarctica (and Greenland) continue to melt. However, some ice sheets in the interior of Antarctica seem to have been getting thicker rather than thinner over the past few years^ref, and scientists have assumed that this is thanks to an accumulation of snow in the interior, which should cushion the continent's impact on sea-level rise. The Intergovernmental Panel on Climate Change in its next report, due 2007, projects Antarctic snowfall to increase by a few per cent for each degree warming. That may now be in doubt. If it hasn't happened in the past you might ask why it should happen in the future. Reconciling models and recent satellite observations with the newly available snowfall record of the past is no easy task. Rushing to the conclusion that all models got it wrong would be premature. The snowfall record is not necessarily in conflict with satellite measurements of ice-mass thickness. Satellite measurements have only been taken for a few years, and a trend on this timescale would be very hard to pick out of the snowfall data. So the satellites could reflect a true trend of increasing ice. On the other hand, it is possible that satellite altimetry measurements haven't been seeing a real trend but rather are 'contaminated' by random variations in snowfall from year to year. Gravity measurements, which measure the weight rather than the height of the ice sheets, are less likely to be skewed by random variations in snowfall. But adjusting this data to account for other gravity changes on the planet is tricky. The method was previously tried in Antarctica, and has now been used to confirm ice-mass losses over Greenland^ref. We always knew that the rather short record of satellite observations might be spoiled by inter-annual variability. The problem is we don't even know all the variables. What we do know is that we need more data and more time. It will take at least another 10 years to figure our whether or not global warming has an impact on Antarctic snowfall.
Pollution is swept to pristine areas of the Arctic by wind and sea. But now researchers have pinned down an important mode of transport that creates local toxic hotspots: sea birds.Canadian researchers have found that lakes in the Arctic that are frequented by northern fulmars (Fulmarus glacialis) can harbour 10-60 times more pollutants than neighbouring, birdless lakes. These pollutants include persistent, toxic compounds such as mercury, DDT and hexachlorobenzene (HCB), which were once common ingredients in pesticides and fungicides. During the summer months, freshwater ponds that sit below the cliffs at Cape Vera on northern Devon Island in the Canadian Arctics harbour the nests of about 20,000 of the migratory fulmars. Pollutants enter the ponds through the birds' excrement. The key to the study was finding an area with several lakes that differed only in the number of birds living above them. By comparing 11 lakes that hosted different bird colonies, the researchers weeded out exactly how much impact the birds and their guano have on the environment. In some of the more contaminated lakes, mercury concentrations approach or exceed the Canadian guidelines for protecting wildlife. Chemicals such as HCB, DDT and the coolants known as polychlorinated biphenyls (PCBs) are very stable and tend to accumulate in the fatty tissue of animals that eat contaminated prey. The fulmars pick up such contaminants from squid, fish and carrion. The birds do not seem to suffer, but they pass on the poisons to predators higher up the food chain. Indigenous people in the area are known to eat animals that are highly contaminated. Preliminary studies show that mercury and PCBs can cause immune system dysfunction, adverse neurological effects and IQ deficits. Other researchers have also seen hints that migratory birds are bringing toxins to the Norwegian Arctic, but it has been hard to quantify the effect in the past. Together, the Norwegian and Canadian studies emphasize the importance of this mechanism of toxin transport. Although wind and sea currents continue to be a major source of pollution to the Arctic as a whole, some locations can gather a much higher level of pollution than others thanks to migratory animals. Such hotspots should be accounted for in monitoring efforts. But the best way to counter the problem, is simply to prevent these chemicals from entering the environment in the first place^ref
Web resources : Arctic monitoring
• the vast land of western Siberia is thawing for the first time since its formation, 11,000 years ago. The area, which is the size of France and Germany combined, could release billions of tons of greenhouse gases into the atmosphere. This could potentially act as a tipping point, causing global warming to snowball, scientists fear. The situation is an ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming. The whole western Siberian sub-Arctic region has begun thawing, and this has all happened in the last 3-4 years. Western Siberia has warmed faster than almost anywhere on the planet, with average temperatures increasing by about 3C in the last 40 years, according to the reports. The warming is believed to be due to a combination of man-made climate change, a cyclical atmospheric phenomenon known as the Arctic oscillation and feedbacks caused by melting ice. The 11,000-year-old bogs contain billions of tons of methane, most of which has been trapped in permafrost and deeper ice-like structures called clathrates. But if the bogs melt, there is a big risk their hefty methane load could be dumped into the atmosphere, accelerating global warming. Scientists reacted with alarm, warning that global warming predictions may have to be revised upward. When you start messing around with these natural systems, you can end up in situations where it’s unstoppable. This is a big deal because you can’t put the permafrost back once it’s gone. The causal effect is human activity and it will ramp up temperatures even more than our emissions are doing. The IPCC speculated in 2001 that global temperatures would rise between 1.4 and 5.8°C between 1990 and 2100. But these estimates only considered global warming sparked by known greenhouse gas emissions. The Siberia situation hints new forces could exacerbate the warming, Viner said—feedback cycles in which the warming itself leads to events that cause further warming. When scientists devised their earlier estimates, he added, “they had no idea” how much this feedback would speed up to the warming.
• about 19,000 km³ of fresh water have flooded into the North Atlantic in the past 40 years : that's > 3 times the annual outflow of the Amazon River. The analysis provides vital clues for modellers who are trying to predict how ocean circulation might change in the future, and how that might affect the climate. There has been lots of evidence of ocean freshening, but this is the first quantification. The results are going to be very useful in putting models to harder tests. Climate scientists fear that fresh water entering the northern Atlantic from melting ice caps and surging rivers might upset the currents that carry heat from the tropics towards the pole, such as the Gulf Stream in the North Atlantic. Such currents are like a conveyor belt: dense, cold, salty water sinks in the north, and returns to the tropics along the ocean floor. Dilution with fresh water could prevent the sinking, and cause the current to falter. There is, as yet, little evidence that the current is weakening. But measurements of freshwater input suggest that slowing will happen^ref. The movie The Day After Tomorrow envisaged a sudden shutdown of the overturning current leaving Europe and America blanketed by ice. Scientists dismiss this scenario as extreme and unrealistic, but there is huge uncertainty about how the ocean and the climate will respond to changes in the circulation. Data on water pressure, temperature and salinity collected by research vessels and floating buoys since 1965 were analyzed. Between 14,000 and 24,000 km³ of fresh water poured into the North Atlantic Ocean between 1965 and 1995, with nearly half arriving in one great pulse of water in the late 1960s. This 'great salinity anomaly', which has been known about for decades, was caused by unusual wind patterns that first built up masses of ice in the north, and then blew it south, where it melted. This melt water migrated to areas of the ocean just south of Greenland that are not greatly involved in overturning waters. This explains why the great salinity anomaly had little effect on ocean currents. Since then, an average of 100 km³ of fresh water per year has accumulated in the more sensitive upper layers of the Nordic seas. At this rate, the circulation could start to weaken within a century. But the amount of fresh water entering the ocean may change. We don't know where all the water is coming from, or exactly how climate change will affect rainfall, run-off and melting ice. So a slowdown in circulation may happen sooner than predicted.

Web resources : Ocean and Climate Change Institute, WHOI
• even if the world stopped burning fossil fuels tomorrow, the emissions already in the atmosphere would cause global temperatures to climb for the next hundred years and the sea level to keep rising for even longer. Researchers have long known that the oceans delay the full effects of climate change because they heat up more slowly than the land, but until now they have had only a vague idea of how this lag will shape our long-term climate. Sophisticated computer models showed just how much climate change we have already signed up for. This course was charted using 2 new models known as 'climate commitment' studies, that allow major components of the climate to interact. They froze the atmosphere as it was in the year 2000 and projected how climate change in our century would play out if the concentrations of greenhouse gases were kept constant. Their models forecast that even in this unrealistically rosy scenario, the earth would warm by an additional 0.5 °C by 2100, a similar rise in temperature to that seen during the previous century. As ocean waters expand in response to this warming, global sea levels would mount by about 10 cm in the next hundred years. But the model does not account for ice cap and glacier melting; a better estimate would be double or triple this value. People think that 10 to 30 centimetres is not much, but a relatively small average rise in sea level is manifested in extreme high tide and storm surge events. When a simpler model was used, it came up with similar results. After 100 years at constant greenhouse gas concentrations, temperatures leveled out, but the sea level kept rocketing up. Looking into the future along a course he thinks comes closer to reality, by fixing the rates of emissions rather than their concentrations, a range of warming from 2 to 6 °C, and a sea level climb of 25 cm per century were predicted. In 400 years that's another metre of sea level rise. Both studies show that some of the damaging effects of climate change are unavoidable. We're already committed to a significant amount of climate change, even if we could stabilize concentrations at some point, and the longer we wait, the worse it gets. In the 2 studies' best-case scenarios, the world could be just tenths of a degree from the temperature the European Union has set as 'unsafe' for the world. Such a rise, of 2 °C over pre-industrial temperatures, would bring more extreme heat waves, storms and flooding. These would intensify crop failure, droughts and disease worldwide. What's important here is that we see the urgency of acting not only to reduce emissions or mitigate climate change in the first place but also to start taking steps to adapt to the eventual new climate and sea level rise conditions that we'll be operating under^{ref1, ref2}
• the heatwave that parched Europe in 2003 caused the continent's grasslands and forests to release huge amounts of CO₂ into the atmosphere. Heatwaves are predicted to become more common as a result of climate change, so the discovery raises fears that forests in temperate regions will become significant emitters of this greenhouse gas. The stifling summer of 2003, which featured temperatures some 6ºC above average and claimed thousands of lives, stunted plant growth through a combination of drought and extreme heat. Usually, Europe's crops and forests are thought to have the net effect of storing carbon as plants grow, rather than releasing it. The CO₂ released as a result of the heatwave was equivalent to the amount of carbon stored over the previous 4 years of normal growth. The researchers measured CO₂ concentrations using towers in 14 forest sites and one grassland site. From half-hourly measurements, they worked out the change in carbon entering or leaving the atmosphere (its flux) from the plants below. Using a computer model, they built a picture of the carbon flux from similar forests and grasslands over the entire continent during the heatwave, and compared this with the picture for 2002. At the height of the summer of 2003, carbon was baking out of Europe's vegetation at a rate of half a billion tonnes per year. By comparison, UK industrial emissions totalled 150 million tonnes of carbon equivalents in 2003. Over the previous 4 years, carbon had been moving at roughly 125 million tonnes per year in the opposite direction, as it was taken up and used by plants to grow^ref. The 2003 event shows that forests, even in temperate areas such as Europe, cannot be guaranteed to suck up CO₂ from the atmosphere. One possibility is that rising temperatures could dent plant growth to the extent that many areas become overall emitters of CO₂. Warmer climes would accelerate the decomposition of old plant matter, releasing more of the gas. This effect on growth was borne out by the disappointing crop yields of 2003. France, hit hardest by the heatwave, lost 20% of its usual harvest. Yields usually rise year on year because of improvements in management. Such an extreme summer has never been recorded before. This was basically unprecedented : it shows there's a danger in assuming that climate change is only going to be gradual. Stopping the problem will take drastic cuts in human-driven emissions of CO₂. In the meantime, land managers may have to make some changes. Farmers might adopt different crops or irrigation programmes, but forest managers can't change so quickly; they will really have to think carefully about what they're planting now. Over the next 50 years the whole world's carbon cycle is going to be altered : it's not just Europe. Climate change is a global phenomenon; it could happen anywhere.
• a combination of climate change and pollution is chewing through Europe's ozone. The protective layer over northern and central Europe was thinner this season than it has been since measurements began 50 years ago. The results come from a campaign (Scout-03 Project) that collected ozone data from 35 stations from Greenland to Tenerife, between January and March 2005. Preliminary analysis of these data plus information from satellites reveals that > 66% of ozone molecules in the arctic stratosphere were destroyed in 2004-2005 winter. By early spring 2005, ozone-depleted air had drifted southwards through large parts of northern and central Europe. Substantial ozone depletion was observed during several cold arctic winters in the 1990s, most notably in 1999/2000 when it was depleted by 65%. But in 2005 it was reduced by at least 70%. Some, but not all, of this loss was replenished by ozone flooding up from the south. In fact, the loss came close to creating a fully fledged ozone hole. Without a healthy layer of ozone for protection, light-skinned Europeans can get sunburned, even in the spring, in 20 minutes, particularly at high altitudes or when snow reflects the sunlight. Researchers are concerned that the radiation may have more dramatic effects on plants and animals, which cannot shield themselves with sunscreen. Ozone is destroyed when oxygen molecules react with aggressive chemicals produced by the decay of chlorofluorocarbons (CFCs). The use of CFCs was largely phased out by the 1987 Montreal Protocol. But CFCs are long-living substances that will continue to destroy atmospheric ozone in polar regions for at least another 50 years. Climate change appears to worsen their effect. High-altitude clouds made of nitric acids, sulphuric acid and water trigger the rapid transformation of CFCs into more aggressive compounds. And unusually cold arctic winters, which are expected to become more frequent as global surface temperatures rise, seem to favour the formation of such clouds. Over the last 40 years or so, we have seen a fourfold increase in the area cold enough for polar stratospheric clouds to form throughout the Arctic. The reasons are not yet entirely understood. Researchers knew it was going to be a particularly cold year in the Arctic in January 2005, and their predictions of severe ozone depletion have now been confirmed. To work out the fate of the arctic ozone layer in the more distant future, scientists will need a better understanding of how greenhouse gases affect temperatures in the upper atmosphere. Current models of the stratosphere predict everything from a dramatic cooling in the Arctic to modest warming.

Emissions of greenhouse gases rose by 1.5% across all of Europe from 2002 to 2003, according to the latest audit. The result marks a disappointing turnaround after levels fell by 0.5% during 2002. The 15 core European Union nations pumped out an extra 53 million tonnes of greenhouse gases in 2003 - a 1.3% hike over 2002. This is mostly accounted for by a surge in power use from coal-fired power stations. This could be due in part to the weather: there was an unusually cold start to 2003, which pumped up heating bills, and a heatwave hit much of continental Europe during the summer, probably increasing use of air conditioning.  Across the 15 pre-2004 European Union (EU) member states, electricity generation rose by 5% in 2003. It is difficult to say whether this rise will be repeated in the figures for more recent emissions, says Andreas Barkman, who helped to produce the report. I don't think anyone can speculate : member states only submitted their latest round of emissions projections on 15 June. According to the European Environment Agency Annual European Community greenhouse gas inventory 1990-2003 and inventory report 2005, Italy, Britain and Finland were the worst culprits in 2003, with overall rises of 15 million, 8 million and 7 million tonnes, respectively. In Italy, most of this rise was due to emissions from households and from manufacturing industries. But in Britain, Finland and elsewhere the hikes were mostly the result of increased electricity generation. Some countries did manage to reduce their greenhouse emissions in 2003. Portugal cut greenhouse gases by 4.5 million tonnes (5.3%) by investing in hydropower. And Ireland shaved some 2 million tonnes (2.6%) off its output by cleaning up its electricity generation, chemical industry and agriculture. The rise is a blow to efforts to meet the targets set by the Kyoto Treaty, which calls for countries to reduce their greenhouse-gas outputs, relative to 1990 levels, by an average of 5% by 2012. The study shows that 2003 emissions in Europe were 1.7% lower than 1990 levels. Averaged over the past five years, levels have been 2.9% below the 1990 mark, which doesn't hit short-term targets for reductions. These figures are disappointing and further reinforce the need for member states to fully implement their emission-reduction actions. Measures such as the EU's carbon-trading scheme and investment in carbon-offsetting projects around the world were not up and running in 2003. Outside Europe, emissions in other industrialized regions look set to grow. In the case of China, many experts think emissions will continue to increase : energy demands in China are rising rapidly as the country develops. The report also issues a stark message to UK prime minister Tony Blair and his fellow leaders of the G8 industrialized nations, who meet in Gleneagles, UK, in July 2005. It is information that will be part of their discussion - that's obvious. But politics will play the major role in those negotiations. How this information will be treated I cannot say.
Web resources : European Environment Agency (EEA)
• fossilized plant spores could carry a record of ancient holes in the Earth's ozone layer. If so, they could test one theory about what caused our planet's biggest mass extinction 250 million years ago. Plant spores contain natural sunscreen chemicals called para-coumaric acids, which protect their DNA from harmful UV-B radiation. The ozone layer normally blocks UV-B radiation. When that layer thins and UV-B levels rise, plants invest more in the screening compounds they put into the spore walls : a British team is studying fossilized spores to work out if the Permian mass extinction, some 252 million years ago, was linked to ozone loss. To test their method, the scientists used the British Antarctic Survey's decades-old collection of spores from the moss Lycopodium magellanicum. These spores were collected on the island of South Georgia, in the South Atlantic, where the skies have seen a larger ozone hole appear each year. Present-day spores have three times as much protective chemical as those from 40 years ago. The team believes this reflects the 14% decrease in average ozone levels above the island in that time. Spores from equatorial climes with no ozone holes showed no variation in sunscreen levels. There are many ideas about the Permian extinction, when almost 90% of all species died. So far, no-one's come up with a definitive mechanism. Some scientists think a comet or meteorite struck the Earth. Others link the event to an enormous volcanic eruption that left a large mass of lava in Siberia. This eruption would have released dust, sulphur and halogen compounds, disrupting the chemistry of the atmosphere and possibly eating a hole in the ozone layer. Spores from the time show severe mutations, which may have been caused by ultraviolet radiation let through by a thinner ozone layer. But at the moment there's no conclusive evidence of an ozone loss at that time. This method will be the first independent test of ozone levels from that period. There is an excellent fossil record of pollen spores, and although the para-coumaric acids break down over time, they leave signature chemicals that should remain in fossils that have not been heated, he says. If it works, we should see a massive increase in pigments during the Permian. With a thinner ozone layer, more ultraviolet radiation would hit plants, forcing them to slather on more sunscreen. They might be onto something useful here. If they find there was an ozone collapse, the next question is how it was triggered. The most likely cause would be the Siberian eruptions. It's unlikely that we'd ever be able to find a single smoking gun for the extinction. But studying fossilized spores may allow them to prove that ozone loss was part of a cocktail of causes. The team have already collected fossilized spores dating from the period from around the world, and the first results are expected by the end of the year^ref.

Web resources : The Ozone Hole Tour
• the end may be in sight for a 15-year argument over a discrepancy in the data on global warming. 3 papers say that temperature trends in the lower atmosphere are consistent with a warming world, countering earlier claims to the contrary. One study deals with satellite measurements, the second with data from weather balloons and the third with predictions of climate models. Taken together, these three results are a major step forward. The problems began in 1990, when an analysis of satellite observations showed the troposphere - the lowest few kilometres of the atmosphere - was warming too slowly compared to the surface for climate models to be correct^ref. Global-warming sceptics seized upon the result. It has been the main crutch of the sceptics when it comes to pooh-poohing global warming, with some success. Some politicians have also cited the data as evidence of the uncertainties in global warming. The 1990 study, headed by John Christy from the University of Huntsville, Alabama, was criticized for the way it used satellite data. This prompted multiple rounds of revision, but never really solved the problem. A recent re-analysis^ref, which claimed to solve the debate, also fell short of being definitive. So why pin any hopes on the new papers? We are converging, we are definitely getting closer. He and Frank Wentz, also at Remote Sensing Systems, tackled a problem with how the satellite data are corrected for the time of day. Although the satellites nominally pass over the same point at the same time each day, in practice drag causes their orbits to sink and the time to drift. Christy's group estimated the temperature at the exact time they wanted, rather than when the satellite actually was overhead, by looking at temperature measurements the satellite took to the east and west of its position. From this they concluded the troposphere was warming by about 0.09 °C per decade. Mears and Wentz instead used data generated by a complex model of the atmosphere to adjust the satellite measurements. On doing so, the troposphere suddenly appears to be warming by almost 0.2 °C per decade, in agreement with climate models^ref. The new work is bound to draw its own criticism, however. It's going to be very interesting to see how this reverberates through the climate-sceptic blogosphere. The second paper points out problems in the temperature record from weather balloons. Steven Sherwood and co-authors argue that changes in instruments have made the records untrustworthy^ref. The problems arise because different manufacturers' instruments heat up by different amounts during the day. At the moment the errors on this data are so big that one can't pin down how much the troposphere is warming. The third piece of research concludes that disagreement between 19 climate models and measurements are more likely to be due to errors in measurements, rather than models^ref. Certain people have too much invested to admit they accept all these reports, but there's quite a bit of agreement in the whole community that these papers are getting closer to the truth.
• soil in Britain has lost an alarming amount of carbon over the past 25 years: more than enough to cancel out the country's reductions in CO₂ emissions. The UK researchers who measured the loss claim its ultimate cause is climate change, which could be increasing the metabolism of soil bacteria so that they spit more carbon into the air. If true, this could feed more greenhouse gas into the atmosphere, causing more warming. But others say the carbon change is due to changes in land use and precipitation patterns, which may not be linked to climate change. Soil samples from almost 6,000 sites throughout England and Wales covering all types of land were measured: grassland, peat land, uplands, woodlands, croplands and scrub. They measured the amount of organic carbon per gram of soil from each site twice between 1978 and 2003. The net loss of carbon across the country was 13 million tonnes a year. That is roughly the amount by which Britain has reduced its carbon emissions from the base level that was set in 1990. It is only a small fraction of the 2,500 million tonnes of carbon thought to exist in the top 30 cm of British soil. But it is still a staggering amount. Losses occurred everywhere, irrespective of land use. This points to climate change as the likely culprit. But the destination of the carbon is unclear. It may be leaching into water systems and deeper soils as bicarbonate and organic materials, or into the atmosphere as CO₂. Their study did not use any tracers to determine where the carbon went. It is crucial to understand the reason for the carbon loss. Until we know why soil is losing carbon it is difficult to know what conservation measures to implement. Others argue that the study made certain assumptions that might not hold water. The team measured only the top 15 cm of the soil, where the majority of carbon changes occur. But their extrapolation to the top 30 cm may make the results misleading. And the study did not keep a detailed history of land use in each site, with data on the amount of fertilization or whether animals grazed the land, for example. The team next step will be to look in detail at sites where land use has not changed, to pin down whether climate change is to blame for the carbon loss or not. In the meantime, the researchers encourage policy-makers to think about conversion of some areas of farmland to forest as a means of stemming carbon loss from soils. In the global warming debate, soil hasn't received enough attention. Most of the attention has focused on reducing fossil-fuel emissions, or studying whether the oceans and forests have the capacity to suck up extra CO₂.  People don't think soil is very sexy. They think it's boring old dirt. The researchers hope their study will change that focus^ref.
Predictions :
• one big problem is a lack of precise knowledge about many of the factors that are plugged in to the models, such as the ability of clouds to reflect heat. In the past, researchers have dealt with these unknowns by making an informed guess at the correct values to feed into their model. Instead of doing this, Murphy's team asked experts to provide a range of likely values for each unknown. They then ran their model many times over, using different values for each unknown, to produce a range of predictions for the future. As a quality control test, they used each version of the model to predict current climate, and weeded out those versions that failed. The main advantage of this approach is that the range of temperatures it predicts is not dependent on having guessed the unknown components correctly. The results suggest that if CO₂ concentrations double over the next hundred years - as many believe they will - the planet will warm by between 2.4 and 5.4°C^ref. A previous estimate released by the Intergovernmental Panel on Climate Change (IPCC), predicted a 1.4 to 5.8°C range. Although it may not seem like much, the 1°C increase at the lower end of the scale could correspond to a significant rise in sea level and an increase in extreme weather events, both of which will now need to be planned for as a near certainty. It also effectively dismisses the argument of sceptics who use the current uncertainty to argue for a 'wait and see approach' to reducing CO₂ emissions.
• to put global warming into context requires knowledge about past changes in solar activity and the role of the Sun in climate change. Solanki et al. propose that solar activity during recent decades was exceptionally high compared with that over the preceding 8,000 years. However, our extended analysis of the radiocarbon record reveals several periods during past centuries in which the strength of the magnetic field in the solar wind was similar to, or even higher than, that of today^ref. Muscheler et al. claim that the solar activity affecting cosmic rays was much higher in the past than we deduced from ¹⁴C measurements. However, this claim is based on a problematic normalization and is in conflict with independent results, such as the ⁴⁴Ti activity in meteorites and the ¹⁰Be concentration in ice cores^ref.
• according to results from the world's biggest climate-modelling study from climateprediction.net, a project that harnesses > 90,000 of the world's desktop computers to predict climate change, a doubling of CO₂ levels could eventually lead to an increase in worldwide temperature of anything between 1.9 ºC and 11.5 ºC. That is a far greater level of uncertainty than the 2-5 ºC rise predicted by the IPCC because climateprediction.net looks at 2,017 possibilities vs just a few dozen simulations. The researchers cannot yet put a timescale on the temperature increases, although they suggest that extreme warming could take decades or centuries. Atmospheric CO₂ levels, currently standing at 379 ppm, are predicted to hit double their pre-industrial level of 280 ppm midway through this century. Policies aimed at keeping greenhouse-gas levels below a safe threshold may miss the point. Uncertainty over global warming may mean that no such threshold can be determined; rather, we may need to keep cutting greenhouse gases for many years to come. Each simulation is a different version of a programme called a general circulation model. This model divides the globe into thousands of sectors, and estimates the future temperature based on certain assumptions such as cloud coverage, the rate of heat movement and rainfall rates. Previous studies have included only the most probable values for these factors, whereas climateprediction.net's power has allowed the researchers to investigate two or three settings for each parameter. All predicted temperature rises. Most were about 3.4 ºC, the average value predicted by the IPCC; many were far more severe. The researchers plan to improve their models, including a more sophisticated picture of how heat travels through the oceans, regional data and a more accurate picture of how temperatures will change during this century^ref


Effects :
• symptoms & signs : the side effects of global warming kill about 160,000 people each year - and this could double by 2020. Warmer temperatures, floods and droughts exacerbate malnutrition, infectious diarrhoea and malaria, mainly in developing nations. For years, climate researchers have struggled with an apparent discrepancy in the data on global warming: temperatures in the lower atmosphere have been rising far slower than models predict, given how fast the Earth’s surface is heating. The discrepancy has been central to the arguments of sceptics about global warming, but it can be explained by interactions between the troposphere and the stratosphere above it.
• the remote and lightless deep-sea floor has long been thought to be protected from events on the surface, such as global warming. But it now seems that climate change impinges on the rhythm of life on the seabed after all : different species are more prevalent at different times, and that these population fluctuations correlate with food availability and major climate events, including the El Niño weather system. For example, Elpidia minutissima, an unprepossessing sea cucumber that is the colour of sediment, showed up in many photos in the years before El Niño, when food was scarce. But it practically disappeared when disturbances wrought by the system apparently increased the food supply. By contrast, a white cucumber that is normally rare, Scotoplanes globosa, thrived in plentiful times.
• coral, tiny animals that forge alliances with algae to harness energy from the Sun, can team up with algae that are more tolerant of heat in response to warmer sea temperatures. Experts had worried that warming could wipe out the world's reefs by 'bleaching' them, a process in which the coloured algae are destroyed to leave the corals in a bone-white, limbo state that can kill off a reef in weeks : some experts had predicted that the world's reefs would all be gone in 20 to 30 years. But now it seems that some algae can survive higher temperatures, and can colonize bleached reefs, restoring them to life. After severe bleaching in the Persian Gulf in 1998, for example, when sea temperatures topped 38ºC, 62% of coral colonies contained the alga Symbiodinium D. In the Red Sea, which enjoys cooler temperatures and had not undergone bleaching, the figure was just 1.5%^ref. In Panama, corals equipped with Symbiodinium D resisted the high temperatures that caused much of the region's coral to bleach in 1997. As a result, the proportion of corals teamed with these algae increased from 43% in 1995 to 63% in 2001. When transferred from 28.5ºC to 32ºC, Symbiodinium C's light-harnessing power was damaged, whereas Symbiodinium D survived unscathed^ref. Many corals live on 'reef flats' in sunkissed shallows, where temperatures are often higher than in the surrounding deep water. Rowan suspects that many of these corals already harbour heat-friendly algae. Corals are still threatened by factors such as water pollution and damage caused by fishing. But most of these factors are easier to reverse than climate change.
• by the end of the century, rising levels of CO₂ in the atmosphere could cut the rate at which marine creatures such as coral and plankton build their calcareous skeletons by 20-50%- with potentially catastrophic effects on the rest of the ocean's wildlife. Nearly half of the extra carbon released into the atmosphere since the dawn of the Industrial Revolution has ended up in the sea. That is good news from one point of view, because it means that, in the long term, the oceans are helping to buffer the effects of global warming by absorbing a lot of CO₂ that would otherwise end up in the atmosphere. But in the short term, it could one day be catastrophic for oceanic ecosystems, as increasingly acidic waters dissolve the calcium carbonate that many marine creatures use to make their skeletons and shells.
• moist Arctic tundra (MAT) experiencing the effects of global warming might lock up carbon through increased plant production : but even though plant growth increases, the tundra habitat as a whole suffers a net carbon loss. The key, he said, may lie in increased microbial activity, which leads to more rapid breakdown of organic matter in the soil^ref.
• climate warming is influencing the lifestyles of animals and plants right across the USA : the changes are bringing rival species into contact with each other and could upset entire ecosystems. Over the past few decades many plants have begun flowering earlier in spring in response to rising temperatures, and animals have migrated north or moved to higher altitudes. One example is the red fox (Vulpes vulpes), which is already widespread across North America but is now pushing north, threatening the weaker Arctic fox (Alopex lagopus). Other more subtle effects may occur as, for example, birds altering the timing of their arrival at breeding grounds find themselves with less food or space. Human-driven climate change has affected species all across the US, from new tropical species arriving in Florida to changes in the basic functioning of ecosystems in Alaska^ref. The greater the rate of climate warming, the smaller the number of species that will be able to adapt without disrupting their lifestyles or ecosystems. Some parts of Alaska warmed by 4°C during the 20th century, compared with a global average of around 0.6°C, with warming for the next century projected to be 2 to 10 times greater than the last.
• fish are shifting their homes northwards, according to an analysis of North Sea populations. Climate change is probably to blame for the move, which could drive some commercially fished species out of the sea completely. Between 1962 and 2001, the North Sea warmed by about 0.6 °C : in response, 15 species had shifted as much as 400 km into cooler waters. A further 6 species had moved into deeper waters in their search for cooler living conditions. Previous work has shown other species moving away from warming environments, including insects, plants and mammals. But the fish seem to be moving more quickly, perhaps because there is little to obstruct them. If surface temperatures rise as climate models predict, blue whiting (Micromesistius poutassou) and redfishes (Sebastes spp.) might completely withdraw from the North Sea in the next 50 years. The loss of such commercial species would severely affect fisheries. We will see dramatic changes to the whole North Sea ecosystem : even a change of one degree can affect fish, who are also under pressure from fishing. Warmer temperatures not only prompt fish to move, but may also affect their ability to reproduce. Cod are going to have trouble as the water warms, and juvenile North Sea herring seem to have difficulty thriving in warmer waters. Fishing management needs to take even more precautions if we are going to let stocks of fish rebuild. A hotter North Sea isn't all bad news. Some species, such as the northern cod (Gadus morhua), grow faster, as long as they are able to find food. However, as some species move further than others in response to changing temperatures, predators may be separated from their normal prey. Warming temperatures just change things, for some species it can be favourable : it doesn't mean that biodiversity has to decline^ref.
• on the Antarctic Peninsula that sticks out from the western side of the continent, the speeds at which several glaciers are surging into the sea have increased 8-fold between 2000 and 2003^ref. This region has also been a focus of concern for some time; in 2002 one of the floating ice shelves, called Larsen B, broke apart in response to the 2.5°C temperature rise the Antarctic has experienced over the past 50 years. The melting ice shelf does not in itself affect sea level, because floating ice displaces its equivalent volume of water. But the new results reveal that the consequences of the break-up are grave. Without the restraining band of ice, the researchers found that several glaciers have surged forward at greater speed. In contrast, two glaciers where the ice shelf remains intact show virtually no speed-up. The Larsen B ice shelf is relatively small. It's not yet clear if the changes seen for the Peninsula glaciers would necessarily scale up to the much larger ice basins that feed into the Western Antarctic ice shelves. And below the Antarctic peninsula, in Western Antarctica, glaciers are now releasing 250 billion tonnes of ice into the Amundsen Sea each year - enough to raise global sea levels by 2 millimetres per decade. The glaciers are getting thinner, because they are losing about 60% more ice into the ocean than is being replaced by fresh snowfall over the continent^ref. The researchers think the reason so much more ice is being lost is because ice at the edges of the continent has thinned, causing it to detach from the bedrock below. No longer anchored to the rock, these marginal ice plains are less able to hold back glaciers pushing toward the coast. For at least one of the glaciers, the Pine Island Glacier, the researchers say that if the present rate of thinning continues, most of the ice plain should float free from its bed within the next 5 years. These glaciers are already the fastest moving in all of Antarctica. But if the ice floats completely free of the rock, they will speed up much more. These Amundsen Sea glaciers alone contain enough ice to raise sea level by 1.3 metres. The thick sheet of ice covering Western Antarctica is a focal point for fears about the effects of climate change on the frozen poles. It is particularly vulnerable because it rests on land that lies below sea level, and there is a danger that if the ice shelves surrounding it were to disintegrate, the entire ice sheet could slide into the sea. If that happened, global sea level would rise by an awesome 5 metres: 5 times greater than the highest current prediction for the increase in sea level over the next century. Sea level rise will be fantastically expensive for developed nations with coastal cities and dire for poor populations in low-lying coastal areas. Almost all the glaciers that flow into the sea off the Antarctic Peninsula are retreating. The discovery comes from an analysis spanning > 50 years of aerial photographs and satellite images. 50 years ago most glaciers were slowly growing in length, but the pattern is now reversed and they're shrinking. Of 244 glaciers studied, 87% have shown a net retreat since photographic evidence was first collected in the 1940s. The trend is probably linked to local climate changes on the peninsula, she explains, where temperatures have risen by around 2ºC over the past 50 years. This is much more than the average temperature increase seen in the rest of Antarctica. The researchers are unsure whether glaciers are likely to be shrinking to the same extent across the rest of the continent. And they are also uncertain about the effects of the coastal glacier retreat. The ice blocks are typically about 2 km wide and several dozen km long. This is small compared to the peninsula's huge, floating ice shelves, which have likewise been disintegrating in recent years. The glacier melt is unlikely to raise sea levels much, or alter local salinity. But if the glaciers retreat much further they may uncover bare rock, which could attract invasive species. That would open up a whole load of new ground for colonization. The survey, which is the most comprehensive of its kind thus far, was completed by researchers from the Cambridge-based British Antarctic Survey and the US Geological Survey, headquartered in Reston, Virginia. Together, they scrutinized some 2,000 images to chart the changing positions of the mouths of the 244 glaciers. The study included glaciers that flow directly into the sea on a westerly stretch of the Antarctic Peninsula, which points up towards South America. The study also revealed that the mean rate of advance of glaciers in the 1940s and 1950s was slower than the current retreat. Widdowson Glacier, for example, has been receding by 1,100 m each year for the past 5 years; in the 1940s it was advancing by just 200 m annually. Temperature is probably not the only cause. During the late 1980s there seems to have been a 'blip', during which the glaciers' retreat was curtailed even though temperatures continued to rise : changing ocean currents may be responsible^ref

Web resources : Scott Polar Research Institute (SPRI)
• man-made pollution during the past century doubled the chances of the heat wave that hit Europe in 2004 summer. The sweltering temperatures of August 2003 left many people, particularly the elderly, struggling to cope. The heat wave caused many thousands of extra deaths, while forest fires ravaged large areas of land, causing $1.6 billion worth of damage in Portugal, for example. Information collected from ice cores and tree rings, scientists had already worked out that the summer of 2003 was probably the hottest in Europe for 500 years. Some saw this as evidence for man-made climate change, but until now no one had attempted a rigorous attribution of its causes. Climate simulations that incorporated man-made emissions predicted summer temperatures for the 1990s that were, on average, 0.5 °C warmer than the simulations without human contributions. A half-degree rise in average expected temperature increases the probability that a given summer will be extremely hot : the mean moves and the whole distribution moves with it. Human influences doubled the likelihood of the 2003 heat wave^ref. This is the first time that a study has worked out how global warming has affected the risk of a particular event : it was only possible to do this because the heat wave of 2003 was so extreme. Because it was so much warmer than previous summers, the team was able to pin down the causes with more certainty. Scientists had not expected that this sort of opportunity would present itself so quickly. In that summer 8 US states and New York City filed a lawsuit against 5 of the country's power companies for this reason. They are demanding cuts in emissions rather than compensation. Defendants in such cases have complained that it is impossible to demonstrate actual damage from emissions such as CO₂. But by clearly attributing the risks of a climate event to man-made pollution, the type of evidence produced in this latest study could in future be used to convince the courts. By the 2040s, > 50% of Europe's summers will be warmer than that of 2003.
• global warming is influencing the genetics of fruitfly populations. Warming over the past 2 decades has encouraged genes to spread from insects at tropical latitudes into flies in more temperate areas. The research adds to a growing body of evidence showing that living things, from insects to plants and other animals, are responding to the planet's shifting climate. Researchers studying Australia's fruitflies (Drosophila) sampled the insects along the country's east coast in 2002 and 2004 and looked at a gene, called Adh, that is known to vary with latitude. Flies in the tropical north are more likely than their southern counterparts to carry a version called AdhS. But that picture has been altered by rising temperatures and the distribution of AdhS had shifted some 400 kilometres south from where it was two decades earlier^ref. 20 years is not long on an evolutionary time scale. The team also found a variant in another gene that had shifted 800 km down the Australian coast. The Adh gene produces an enzyme called alcohol dehydrogenase, which helps the human system to deal with alcohol consumption, although its purpose is different in the fly, where the 'S' version seems to encourage survival in hot, dry conditions. The geographical shift of AdhS is probably due to climate change. Temperatures along Australia's east coast are rising by around 0.2 ºC every 10 years, and annual rainfall is decreasing by 10-70 mm per year. The discovery shows the power of latitude-linked genes to reveal the effects of climate change on living populations. According to an analysis of the amount of heat stored in the oceans, every m² of the planet is receiving net power of 1 W from the Sun, after subtracting energy that is radiated out into space^ref. This provides yet more evidence that Earth is being slowly but surely heated. Given all the energy currently stored in the world's oceans, further global warming could only be stopped immediately by halving the amount of CO₂ in the atmosphere, but that is not practicable in the foreseeable future, so the world is going to become warmer
• corals and plankton are at risk of being destroyed by the rising acidity of the world's oceans as the waters absorb carbon dioxide from the air, British scientists have warned in the Royal Society Working Group on Ocean Acidification. Ocean Acidification Due to Increasing Atmospheric Carbon Dioxide (2005). The only solution is drastic cuts in CO₂ emissions, far beyond those called for by the Kyoto treaty. Without such measures, dissolved CO₂ could increase the acidity of sea water by as much as 0.5 pH units by the end of this century, from 8.2 to around 7.7. Such a change would upset the oceans' chemical balance and kill off some marine life. There is no way for us to remove this CO₂ from the ocean. It will take many thousands of years for natural processes to remove it. As long as we keep putting carbon dioxide into the atmosphere, he added, it will keep finding its way into the ocean. As carbon dioxide dissolves in water it forms weak carbonic acid, which can dissolve materials such as shells and coral. Since the beginning of the Industrial Revolution, humans have pumped an estimated total of 450 billion tonnes of carbon dioxide into the atmosphere, around half of which has ended up in the oceans. He and his colleagues are calling for < 900 billion tonnes to be added during this century - a tall order given the burgeoning industrial development of China and India. This target would call for huge cuts, with emissions by 2100 reaching half their present levels. This is far in excess of the more modest targets set by the Kyoto treaty, which calls for developed nations to cut their emissions, relative to 1990 levels, by an average of 5% by 2012. Without action to combat acidification, the effects are likely to be strongest in the Southern Ocean around Antarctica. Tiny shell-forming molluscs called pteropods live here and help form the basis of Antarctic food chains, says Carol Turley of the Plymouth Marine Laboratory. This is another very strong argument for reducing carbon dioxide emissions. Other potential victims would be coccolithophores, tiny hard-shelled plankton that can blossom in huge numbers, forming swarms visible from space. And while corals face bleaching and death from higher-temperature waters, the report's authors note that acidic waters are a big problem too. They calculate that even under the lowest future scenarios for carbon emissions produced by the Intergovernmental Panel on Climate Change, corals such as those on Australia's Great Barrier Reef could be all but wiped out by 2050 by acidity. There are a few theoretical quick fixes for ocean acidification, such as dumping limestone into the water to boost mineral levels and buffer the ability of carbon dioxide to change the pH. But we would have to dig up 60 km² of chalk to a depth of 100 m every year to provide enough. This is unfeasible and risks causing further damage to the planet. The only answer is to stop burning so much fossil fuel. We are addicted to fossil-fuel burning like a smoker is addicted to nicotine. Like smoking, there are many adverse effects - we need to wake up and heed the doctor's orders.
• sand dunes in the Kalahari Desert in Africa, which have been immobile for thousands of years, will soon start to move again. The wandering dunes may affect hundred of thousands of people in southern Africa. Researchers have long warned that some of the driest and poorest parts of the world are getting drier, causing deserts to grow, and the anticipated climate change might also affect the movement of dunes within deserts. Dunes move when sand grains on one side are picked up by the wind and deposited on the other. But the speed of movement varies greatly depending on factors including the shape and size of the dunes, moisture content in the sand, and wind speed. Dune movement can be dramatically slowed or prevented by sparse vegetation. When vegetation cover drops below 14%, erosion speeds up significantly. The result is a self-perpetuating system in which the blown sand smothers remaining plants, destroying ecosystems and prompting further erosion. Using data collected from 1960 to 1991, Thomas and his team applied a climate model to investigate the effects of anticipated loss of vegetation cover, reduced moisture content, and increased wind energy on African desert regions. Their simulations revealed a significant increase in dune activity in the southern Kalahari by 2039. By 2099, sand dunes throughout South Africa, Angola and Zambia will be on the move, they predict; such a phenomenon has not occurred in the past 14,000 to 16,000 years. These shifting sands are likely to destroy local ecosystems, making any kind of farming or other use of nearby land even more difficult^ref. The model included seasonal variations in annual rainfall and the likely impact of an increase in atmospheric greenhouse gases on temperature. It did not, however, include the influence of higher CO₂ levels on plant productivity, nor human impacts such as increased agriculture in surrounding areas. Local people are aware of the problem, but often act to worsen it. Large-scale sheep farming in the northern part of South Africa, for example, reduces available ground water, because it requires extensive well digging. Fighting the process of vegetation loss and dune movement would require major adaptations. One possible solution would be to plant new vegetation. But dune ecosystems are very sensitive and differ greatly from region to region. It would take many years of careful tending to stop a moving dune from wandering around.
• fossil hunters in Yellowstone National Park have discovered an unusual way to record the effects of climate change. Specimens from the past 3,000 years suggest that salamanders have grown bigger as the climate has warmed, and may continue to change as temperatures rise and lakes dry up. During development, tiger salamanders (Ambystoma tigrinum) can metamorphose and head for land rather than staying in the water. And warmer climes have made salamanders on land outgrow their water-based relatives. Hadley and her colleagues examined almost 3,000 salamander vertebrae from the park's Lamar Cave in Wyoming. The difference is particularly pronounced in the warmest period of Yellowstone's history, between 1,150 and 650 years ago. Hotter conditions allow for more abundant food and faster growth rates, they suspect, and such effects are expected to be less marked in the water, where temperature changes are smaller. The researchers analysed fossils from 15 different layers of rock in Lamar Cave. They dated the deposits and divided them into five time intervals corresponding to five periods with different climates over the past 3,000 years. Warm weather is indeed likely to encourage rapid growth in land-based salamanders. Food is likely to be more abundant, and the cold-blooded creatures would have a higher metabolic rate and therefore speedier growth. In water, on the other hand, it is cold weather that encourages the salamanders to beef up: their level of thyroid hormone falls, so they keep on growing for longer. Some experts argue, however, that it is not climate that has caused the land-based salamanders to grow larger. Other factors, such as overall population numbers, may also influence size by influencing the intensity of competition for food. To really understand how different organisms respond to rapid climate change, researchers need to look at other prehistoric time periods. Although the fossils of land and water salamanders differ in size, no difference was found in the overall number of those living on the land, relative to the number in the water, suggesting that climate did not influence the decision to metamorphose. This demonstrates that species will respond to climatic change in ways we're not always able to anticipate. Still, she predicts that if the climate continues to get hotter, the ponds will start to dry out in Yellowstone, forcing more salamanders to live on land. If the number of water-based salamanders slumps too much, she warns, the food chain of the lakes could be disrupted. (Bruzgul J. E., Long W. & Hadly E. A. BMC Ecol., 5. 7 (2005).)

Web resources :
• Worldwide look at amphibians
• Tiger salamanders
• Amphibians in Yosemite
• climate change and human health : In 1998, Hurricane Mitch dropped six feet of rain on Central America in three days. In its wake, the incidence of malaria, dengue fever, cholera, and leptospirosis soared. In 2000, rain and 3 cyclones inundated Mozambique for 6 weeks, and the incidence of malaria rose fivefold. In 2003, a summer heat wave in Europe killed tens of thousands of people, wilted crops, set forests ablaze, and melted 10% of the Alpine glacial mass. This summer's blistering heat wave was unprecedented with regard to intensity, duration, and geographic extent. More than 200 U.S. cities registered new record high temperatures. In Phoenix, Arizona, sustained temperatures above 100°F (38°C) for 39 consecutive days, including a week above 110°F (43°C), took a harsh toll on the homeless. Then came Hurricane Katrina, gathering steam from the heated Gulf of Mexico and causing devastation in coastal communities. The map shows the 3-day average of sea-surface temperatures from August 25, 2005, through August 27, 2005, and Hurricane Katrina growing in strength and breadth as it passes over the unusually warm Gulf of Mexico. Yellow, orange, and red areas at or above 82°F (27.8°C, the temperature required for hurricanes to strengthen). Since the 1970s, the number of category 4 and 5 hurricanes has increased as sea temperatures have risen (From the Scientific Visualization Studio of the National Aeronautics and Space Administration) :


These sorts of extreme weather events reflect massive and ongoing changes in our climate to which biologic systems on all continents are reacting. So concluded the United Nations Intergovernmental Panel on Climate Change (Houghton JT, Ding Y, Griggs DJ, et al., eds. Climate change 2001: the scientific basis: contribution of the Working Group I to the third assessment report of the Intergovernmental Panel on Climate Change. Cambridge, England: Cambridge University Press, 2001) a collaboration of more than 2000 scientists from 100 countries. In 2001, the panel concluded that humans are playing a major role in causing these changes, largely through deforestation and the combustion of fossil fuels that produce heat-trapping gases such as CO₂. Since 2001, we've learned substantially more. The pace of atmospheric warming and the accumulation of CO₂ are quickening; polar and alpine ice is melting at rates not thought possible several years ago (Hassol SJ. ACIA, Impacts of a warming Arctic: arctic climate impact assessment. Cambridge, England: Cambridge University Press, 2004); the deep ocean is heating up, and circumpolar winds are accelerating; and warming in the lower atmosphere is retarding the repair of the protective "ozone shield" in the stratosphere. Moreover, ice cores that are drilled in Greenland indicate that the climate can change abruptly. Given the current rate of carbon dioxide buildup and the projected degree of global warming, we are entering uncharted seas. Increase from 1992 (Left) to 2002 (Right) in the Amount of the Greenland Ice Sheet Melted in the Summer :

The extent of seasonal melting on the Greenland ice sheet has been observed by satellite since 1979. The melt zone (orange), where summer warmth turns snow and ice around the edges of the ice sheet into slush and water, has been expanding inland and to record-high elevations in recent years. When the meltwater seeps through cracks in the ice sheet, it may accelerate melting and allow ice to slide more easily over bedrock, speeding its movement to the sea. In addition to contributing to a rising sea level, this process adds freshwater to the ocean, with potential effects on ocean circulation and regional climate. As we survey these seas, we can see some of the health effects that may lie ahead if the increase in very extreme weather events continues^ref. Heat waves like the one that hit Chicago in 1995, killing some 750 people and hospitalizing thousands, have become more common (Houghton JT, Ding Y, Griggs DJ, et al., eds. Climate change 2001: the scientific basis: contribution of the Working Group I to the third assessment report of the Intergovernmental Panel on Climate Change. Cambridge, England: Cambridge University Press, 2001). Hot, humid nights, which have become more frequent with global warming, magnify the effects. The 2003 European heat wave — involving temperatures that were 18°F (10°C) above the 30-year average, with no relief at night — killed 21,000 to 35,000 people in five countries. But even more subtle, gradual climatic changes can damage human health. During the past two decades, the prevalence of asthma in the USA has quadrupled, in part because of climate-related factors. For Caribbean islanders, respiratory irritants come in dust clouds that emanate from Africa's expanding deserts and are then swept across the Atlantic by trade winds accelerated by the widening pressure gradients over warming oceans. Increased levels of plant pollen and soil fungi may also be involved. When ragweed is grown in conditions with twice the ambient level of carbon dioxide, the stalks sprout 10% taller than controls but produce 60% more pollen. Elevated carbon dioxide levels also promote the growth and sporulation of some soil fungi, and diesel particles help to deliver these aeroallergens deep into our alveoli and present them to immune cells along the way. The melting of the earth's ice cover has already become a source of physical trauma. In Alaska, Inuits report an increase in accidents caused by walking on thin ice (Hassol SJ. ACIA, Impacts of a warming Arctic: arctic climate impact assessment. Cambridge, England: Cambridge University Press, 2004). Ocean warming and Arctic thawing are also spawning severe winter storms and hazardous travel conditions in the continental USA. Although tropical sea surfaces are warming and becoming saltier, parts of the North Atlantic are freshening from melting polar ice and increased amounts of rain falling at high latitudes. Contrasting barometric pressures over changing oceans increase winds and propel storms. Meanwhile, in the past three decades, widening social inequities and changes in biodiversity — which alter the balance among predators, competitors, and prey that help keep pests and pathogens in check — have apparently contributed to the resurgence of infectious diseases. Global warming and wider fluctuations in weather help to spread these diseases: temperature constrains the range of microbes and vectors, and weather affects the timing and intensity of disease outbreaks (McMichael AJ, Campbell-Lendrum DH, Corvalán CF, et al., eds. Climate change and human health: risks and responses. Geneva: World Health Organization, 2003:250). Disease-bearing ticks in Sweden are moving northward as winters become warmer, and models project a similar shift in the USA and Canada. The encroachment of human housing on wilderness and reductions in the populations of predators of deer and competitors of mice are largely responsible for the current spread of Lyme disease. Mosquitoes, which can carry many diseases, are very sensitive to temperature changes. Warming of their environment — within their viable range — boosts their rates of reproduction and the number of blood meals they take, prolongs their breeding season, and shortens the maturation period for the microbes they disperse. In highland regions, as permafrost thaws and glaciers retreat, mosquitoes and plant communities are migrating to higher ground (Epstein PR, Diaz HF, Elias S, et al. Biological and physical signs of climate change: focus on mosquito-borne diseases. Bull Am Meteorol Soc 1998;78:409-17). The increased weather variability that accompanies climate instability contributed to the emergence of both the hantavirus pulmonary syndrome and West Nile virus in the USA. 6 years of drought in the Southwest apparently reduced the populations of predators, and early heavy rainfall in 1993 produced a bounty of piñon nuts and grasshoppers for rodents to eat. The