Greenhouse gases are any gas in the tamosphere that can prevent heat in the amosphere from escaping into outer space. Carbon dioxide is one of the greenhouse gases, and the most problematic. It is emitted whenever hydrocarbons - fossil fuels (gasoline, coal) or wood - are burnt. The most difficult to overcome is that of the emission from cars. However most of carbon dioxide emitted is the result of burning coal in the production of electricity. It cost twice to produce a megawatt of electricity if natural gas is used. In 2001, the US mined 1.1 billion tons of coal.

In 2001, The President of the United States, George W. Bush, rejected the United Nations-backed Kyoto Treaty. White House said the Treaty would devastate an economy already jolted by the Sept 11 attacks and put 'millions of Americans out of work'. The European Union said it still believes the Kyoto Treaty remains the best response to global warming. Japan said it would press on with ratification of the Kyoto pact.

January, 2002 - The British Antarctic Survey reported that winter temperatures of 17 lakes on Antarctica's Signey Island increased by up to 1.3 deg C between 1980 and 1995. Photographic analysis showed Signey's permanent ice cover had receded by about 45 per cent since 1951. Also the lakes were covered with ice for 63 fewer days in 1993 than in 1980. Extra time for water to absorb sunlight means more than just temperature change. Water heats up three times faster than air. Polar lakes are considered early detectors of environmental change. Scientists agree air temperatures have risen in recent decades five times faster than average global temperatures. We need to start thinking about how these types of temperature changes are going to affect our ecosystems.

March 19, 2002 - The US National Snow and Ice Data Centre (NSIDC) said the Larsen B ice shelf which covers an area of 3,250 sq km of off the Antarctic Peninsula's eastern coast, has shattered over a 35-day period. The 720-billion-tonne block of ice which could be as old as 12,000 years, began to disintegrate on Jan 31. The shattered ice formed a plume of thousands of icebergs adrift in the Weddell SeaWith continued warm summers, other ice shelves are on the brink of collapse.

NSIDC researcher Ted Scambos explains that in late summer as the climate warms meltwater fills smaller cracks in the shelf and its weight fractures the ice mass. If the more ice shelves disintegrate and the glacial ice flow off the Antarctica continent it could raise the global sea levels, endangering low-lying land areas.

The centre said the rate of warming was around 0.5 deg C per decade, and the trend could be observed back at least to the late 1940s. The largest ice shelf in the world is the 500,000-sq-km Ross Shelf south of New Zealand.

April, 2002 - Stanford University professor of geophysics Kevin Arrigo in a paper in Geophysical Research Letters wrote that the B-15 iceberg, the size of Jamaica, calved off the Ross Ice Shelf in March 2000 has blocked the Ross Sea, which is the southernmost limit of the Pacific Ocean. At about 11,000 sq km, was one of the largest icebergs on record. This left large stretches of normally open ocean covered with ice during crucial spring and summer months. Sea ice is very effective at blocking light, so the phytoplankton couldn't grow as there was just too much ice around. A satellite sensor of the US National Aeronautical and Space Administration (Nasa) has revealed B-15 has cut sea phytoplankton, the base of the Antarctic marine food web, by 40 per cent, and the small fish krill has gone. The Ross Sea was home to 25 per cent of the world population of Emperor penguins and 30 per cent of Adelie penguins. 'There was a lot less food nearby for penguins, so they had to go much farther to feed leaving their nests exposed to predators for longer periods of time. So penguin breeding success was much lower last year.

March 26, 2002 - Australia's National Tidal Facility (NTF) at Flinders University in South Australia, has set up a sophisticated tidal gauge on Funafuti, Tuvalu's capital, since 1993. The island of Tuvalu is north of Fiji. It reported that the Pacific Ocean is not rising. "As at February 2002, based on short term sea level rise analyses...for the nearly nine years of data return show a rate plus 0.9 millimetres per year."

Independent of London. April 2002 - The UN Environment Programme's regional glacier specialist, Mr Surendra Shrestha, told a press conference: 'Our findings indicate that 20 glacial lakes in Nepal and 24 in Bhutan have become potentially dangerous as a result of climate change.' Average temperature in the Himalayas has risen by 1 deg C since the 1970s. The UNEP's findings are based on a two-year study of old and new maps, aerial and satellite photographs and the evidence of sherpas who saw tiny lakes in their childhood becoming large ponds in two generations. The Raphstreng Tsho glacial lake in Bhutan, for example, was 1.6 km long, 0.96 km wide and 80 m deep in 1986. Nine years later, it was 1.94 km long, 1.13 km wide and 27 m deeper. The Tsho Rolpa lake in the Dolakha district of Nepal covered 0.23 sq km in the late 1950s. But today, with the melting of a nearby glacier, it has swollen to six times the size. One of these could burst its banks in five to 10 years

According to Mr Pradeep Mool, a remote sensing expert with the International Centre for Integrated Mountain Development, a flood from the Tsho Rolpa lake could cause serious damage down to the village of Tribeni, 108 km downstream, threatening about 10,000 human lives.

UNEP executive director Klaus Toepfer said: 'If the glaciers continue to retreat at the rates being seen in places such as the Himalayas, many rivers and fresh-water systems could run dry, threatening drinking water supplies as well as fisheries and wildlife.'

Dec 2002 The World Meteorological Organisation (WMO) said in its annual statement on the global climate that since 1976, global surface temperatures have been rising at three times the average rate recorded over the past century. Mr Kenneth Davidson, head of the WMO's climate programme, said this increase is unprecedented in the 1,000-year record that includes ice core sampling, seabed mud and tree ring samples. 1998 is the warmest year on record since direct weather data was first gathered in 1860.

Overall, the worldwide mean surface temperature for 2002 rose by about 0.5 deg C, compared to a 1961-1990 annual mean used as a reference point. Surface melting of the ice cap in Greenland was also reported to be greater than in previous known records. The Arctic ice cap shrank to its smallest area in September than in any other period since satellite observations started 24 years ago. This increase nudged out 2001, when mean surface temperature rose 0.42 deg C, as the second warmest year. The overall rise in surface temperatures since 1900 now exceeds 0.6 deg C. The 10 warmest years on record have occurred since 1987.

WMO says the warmer temperatures are largely caused by pollution, notably by emissions which effectively add a layer of insulation in the upper atmosphere.

WMO said this year was also marked by the start of a 'moderate intensity' El Nino, a disruption of sea temperatures around the southern Pacific basin which triggers extreme weather across much of Asia, the Americas and sub-Saharan Africa.

February 2002 was the second-driest month in the U.S. history since reliable record-keeping began in 1895. The autumn and winter period from Sept 1 through Feb 28 was the driest for Arizona, Connecticut, Delaware, Massachusetts, New Jersey, South Carolina and Virginia and the second-driest for Maryland, North Carolina, Rhode Island and West Virginia. Maine had its driest winter in the 108 years that records have been kept.

Ozone Depleting Chemicals