UN report on climate change warns of catastrophe

Mumbai: A scientific report from the United Nations' Intergovernmental Panel on Climate Change (IPCC) — the most authoritative climate change study ever produced — has prompted new calls for concerted action to ward off soaring global temperatures and rising sea levels.

The report, which put the blame directly on humans, says without action, global warming will deliver catastrophic change, including droughts, flooding, more tropical storms, heat waves and the disappearance of arctic ice in the sea in the second half of this century.

The IPCC report identified that human behaviour is responsible for more than 90 per cent of environmental instability that causes climate changes over thousands of years.

The global community of eminent scientists who prepared the report said that at a conservative estimate a three-degree rise in global temperatures is on the cards - and possibly 6.4 degrees by the end of the century.

Launching the report in Paris, Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change (IPCC), made it clear that the scientists were simply telling the facts as they are and it was for governments to act.

The document has the effective endorsement of the global community, although the report of doom does not shock governments the least, Pachauri pointed out.

The report comes after last year's Stern Report commissioned by UK prime minister Tony Blair, and last month's European Commission report proposing an EU effort to keep the rise temperatures well below two degrees.

The cost to the planet, in human and financial terms, would be incalculable.

EU experts have now admitted that rising temperatures will kill an extra 11,000 people in Europe a year within 10 years — even if politicians take serious action now.

A temperature rise of only 2.2 degrees would trigger such a mortality increase - and from 2071 the annual extra deaths in southern Europe would rise to 29,000 people.

Residents of Italy and Spain will suffer most from drought, fire, dry soil and other climate-change related factors.

Even in relatively cold northern Europe, 27,000 people would die a year by then from the warmer climate.

However, the hotter weather would save 20,000 people who would otherwise die from the cold.

Those figures are seen as conservative estimates in the light of the present report and it is now believed that there is a 50 per cent chance that global temperatures will rise this century by more than five degrees centigrade.

Sea levels will rise by more than half a metre, destroying one-third of Africa's 'coastal infrastructure'.

Similar devastation would hit Europe's coasts and the UK.

Long-term holiday patterns could change in Europe - with no need for northern Europeans to head south if the aim is a suntan.

They said the world was in for centuries of climbing temperatures, rising seas and shifting weather patterns — unavoidable results of the buildup of heat-trapping gases in the atmosphere

The report said warming and its harmful consequences could be substantially blunted by prompt action.

Although the report provided no new evidence of a climate apocalypse now, and avoided recommending courses of action, UN agency officials that created the panel in 1988 said it spoke of the urgent need to limit looming and momentous risks.

"In our daily lives we all respond urgently to dangers that are much less likely than climate change to affect the future of our children," said Achim Steiner, executive director of the United Nations Environment Programme, which administers the panel along with the World Meteorological Organization

The report is the panel's fourth assessment since 1990 on the causes and consequences of climate change, but it is the first in which the group asserts with near certainty - more than 90 per cent confidence - that carbon dioxide and other greenhouse gases from human activities have been the main causes of warming in the past half century.

Temperatures, sea levels to rise
The new report says the global climate is likely to warm 3.5 to 8 degrees by 2050 Fahrenheit if carbon dioxide concentrations in the atmosphere reach twice the levels of 1750, before the Industrial Revolution.

Many energy and environment experts see such a doubling, or worse, as a foregone conclusion after 2050 unless there is a prompt and sustained shift away from the 20th-century pattern of unfettered burning of coal and oil, the main sources of carbon dioxide, and an aggressive expansion of nonpolluting sources of energy.

And the report says there is a more than a 1-in-10 chance of much greater warming, a risk that many experts say is far too high to ignore.

Even a level of warming that falls in the middle of the group's range of projections would be likely to cause significant stress to ecosystems, according to many climate experts and biologists. And it would alter longstanding climate patterns that shape water supplies and agricultural production.

Moreover, the warming has set in motion a rise in global sea levels, the report says. It forecasts a rise of 7 to 23 inches by 2100 and concludes that seas will continue to rise for at least 1,000 years to come. By comparison, seas rose about 6 to 9 inches in the 20th century.

Policy briefing
The meeting released a 20-page summary for policymakers, which was approved early in the morning by teams of officials from more than 100 countries after three days and nights of wrangling over wording with the lead authors, all of whom are scientists.

Generally, the scientists said, more precipitation will fall at higher latitudes, which are also likely to see lengthened growing seasons. Semi-arid subtropical regions, already chronically plagued by drought, could have a further 20 per cent drop in rainfall under the panel's midrange outlook for increases in the greenhouse gases.

The summary added a new chemical consequence of the buildup of carbon dioxide to the list of mainly climatic and biological effects foreseen in its previous reports: a drop in the pH of seawater as oceans absorb billions of tons of carbon dioxide, which forms carbonic acid when partly dissolved. The ocean would stay alkaline, but marine biologists have said that a change in the direction of acidity could imperil some kinds of corals and plankton.

The report essentially caps a half-century-long effort to discern whether humans, through the buildup of carbon dioxide and other gases released mainly by burning fuels and forests, could influence the earth's climate system in potentially momentous ways.

Government officials are involved in shaping the summary of each report, but the scientist-authors, who are unpaid, have the final say over the thousands of pages in four underlying technical reports that will be completed and published later this year.

Big questions remain about the speed and extent of some impending changes, both because of uncertainty about future population and pollution trends and the complex interrelationships of the greenhouse emissions, clouds, dusty kinds of pollution, the oceans and earth's veneer of life, which both emits and soaks up carbon dioxide and other such gases.

Back to Ice Age?
Should greenhouse gases continue to accumulate in the atmosphere at even a moderate pace, average temperatures by the end of the century could match those last seen 125,000 years ago, in the previous warm spell between ice ages, the report said.

At that time, the panel said, sea levels were 12 to 20 feet higher than they are now. Much of that extra water is now trapped in the ice sheets of Greenland and Antarctica, which are eroding in some places.

The panel said there was no solid scientific understanding of how rapidly the vast stores of ice in polar regions will melt, so their estimates on new sea levels were based mainly on how much the warmed oceans will expand, and not on contributions from the melting

The conclusions came after a three-year review of hundreds of studies of past climate shifts; observations of retreating ice, warming and rising seas, and other changes around the planet; and a greatly expanded suite of supercomputer simulations used to test how the earth will respond to a growing blanket of gases that hold heat in the atmosphere.

The summary also described far-flung ramifications for both humans and nature.

"It is very likely that hot extremes, heat waves and heavy precipitation events will continue to become more frequent," said the summary.

Government officials are involved in shaping the summary of each report, but the scientist-authors, who are unpaid, have the final say over the thousands of pages in four underlying technical reports that will be completed and published later this year.

Big questions remain about the speed and extent of some impending changes, both because of uncertainty about future population and pollution trends and the complex interrelationships of the greenhouse emissions, clouds, dusty kinds of pollution, the oceans and earth's veneer of life, which both emits and soaks up carbon dioxide and other such gases.

But a broad array of scientists, including authors of the report and independent experts, said the latest analysis was the most sobering view yet of a century of transition — after thousands of years of relatively stable climate conditions — to a new norm of continual change.