Our weather is changing now and those in Power don't give a shit.

national | miscellaneous | news report Wednesday April 03, 2002 14:41 by van outen

from Guardian Newspaper

TWO TIGHT vortices of ultra-cold air have started dancing around the North and South Poles, causing unprecedented weather extremes, according to a secret research briefing by a leading American expert on the workings of the world's atmosphere.

A video of Dr Susan Solomon briefing a closed session of the world's top climate change scientists was obtained by the Australian Financial Review via a delegate who said the public should be told what the delegates have now gone home to tell their presidents and prime ministers.

Dr Solomon said the ozone hole over Antarctica, and lesser ozone depletions over the Arctic, have now established a pattern in which vortices of extremely cold air are becoming trapped over the polar regions instead of performing their natural function of spreading to lower latitudes and cooling global weather systems.

Dr Solomon led the 1986-87 research expedition to Antarctica that proved that chlorofluorocarbons, or CFCs, in aerosol sprays were accumulating above the poles and driving a complex chemical chain reaction that destroyed the ozone layer in the upper atmosphere.

After hearing from Dr Solomon and other researchers, some delegates said they would advise their governments that the option of waiting for more evidence of climate change was being overtaken by the real thing. Outbreaks of extreme weather would take an unacceptable toll of human life, farm production and social infrastructure, including transport systems and buildings.

The very day Dr Solomon was telling the Joint Scientific Committee of the World Climate Research Programme how the Antarctic vortex could cause a rapid distintegration of some of its ice shelves, the Larsen B formation collapsed, spawning thousands of gigantic icebergs.

However, Dr Solomon's thesis shocked her fellow scientists even more than the satellite images showing such an abrupt change to Antarctic topography.

She told them she had established a direct link between the chemical poisoning of the stratosphere and not just the ice shelf collapse, but the increasingly bizarre outbreaks of abnormal hot and cold weather in different parts of the world.

That poisoning comes from the thin but potent accumulation of synthetic CFCs and other "halons" that have caused the major ozone hole to form over Antarctica and similar holes above the Arctic.

Until now no link has ever been suggested between the very recent disappearance of atmospheric ozone over the poles and rapid, large-scale changes in the vast but slowly moving ice features of Antarctica that have been stable over time scales of tens of thousands of years.

Dr Solomon explained that ozone's natural role is to convert ultraviolet radiation into heat as it absorbs and prevents it from reaching the ground with its full and harmful intensity.

Where that ozone has been removed by the complex chain reactions that can only take place in polar air masses, the upper and middle layers of the atmosphere are now much colder than before.

This fierce cooling is, in turn, deepening the centres of low pressure over both polar regions around which the weather patterns previously danced in a lazy vortex that circulated cold air to the mid-latitudes.

Dr Solomon said these vortices have now shrunk or "tightened" into much faster, colder and smaller patterns of circulation, which, depending on other influences from oceans or land masses, are displacing normal weather patterns.

She made a direct link between the spectacular and persistent warming of much of North America and the creation of winter storms paths that have put northeast Canada, much of Scandinavia and parts of southern Europe and the Middle East under unexpectedly heavy snow falls.

In Antarctica, the result has been to confine extremely cold air to the centre of the main continent, preventing it circulating over the more northerly reaches of the peninsula. This exposed the Larsen Ice Shelf to the comparative warmth of the adjacent ocean and lifted temperatures so far above freezing that glacial disintegration became swift and inevitable.

This summer has been one of the coldest ever recorded in the southern third of Australia and the culprit is a blocking weather system in the southern Indian Ocean of a type never before observed.

While it has forced cooler air over the bottom of Australia, it also drove pack ice hard on to sections of the Antarctic coastline that would normally have been open water. The surface of the "wind fast" icebergs became dotted with extensive pools of melt water, a sight never previously recorded along the margins of Antarctica.

Delegates said these were massive, unpredicted events, yet other global warming consequences predicted by newer computer modelling of climate change appear to be coming true. Oxygen levels are declining as forecast in the mid-levels of the Antarctic deep ocean currents critical for distributing nutrients rich in dissolved oxygen to warmer waters. Southwest Australia is 26 years into a drought that may be confirmation of predictions that greenhouse-induced warming will turn that part of the continent into a desert.

Dr Kevin Trenberth, a delegate from the National Climate and Atmospheric Research Laboratory in Colorado, says that while global warning is real, it is real in ways that do not sit well with the science-by-slogan mentality that turns every hot day into a sign of global melt-down.

"The cycles of the past, both cooler or hotter than today, are no guide to the future. Within the next 20 to 50 years, the world will experience weather events for which there is no precedent.

"We have changed the chemistry of the atmosphere with a range of compounds that have never occurred in the past," Dr Trenberth said.

"What we must do is to map in great detail the origins and distribution of these chemical changes so we can accurately predict what they will do and look at what we can do if we don't like what we see."

Dr Trenberth said the true magnitude of global warming had been disguised because "a lot of the extra heating is soaked up by enhanced evaporation".

"Where we see an air temperature rise of 1 degree C we are finding a 6% to 7% rise in the moisture-carrying capacity of the atmosphere. This is driving us into situations where the rain falls a lot harder, but in fewer events, making extremes of flooding increasingly likely."

Dr Graeme Pearman, chief of atmospheric research at the Commonwealth Scientific and Industrial Research Organisation, said concentrations of carbon dioxide, methane and nitrous oxide were at their highest levels for at least 400,000 years.

"There is nothing we can do to stop those concentrations doubling in the next 50 years. By 2050, the two billion people who currently have no industrial energy cycle will be generating their greenhouse gases because of economic growth and there will be at least another two billion increase in global population."

"We have some urgent choices to make." - The Observer

Tuesday, 2-April 2002