Global Warming (II)

International report details impact of global warming

By James Kanter and Andrew C. Revkin

Published: April 6, 2007


BRUSSELS: Earth's climate and ecosystems are already being affected by the atmospheric buildup of smokestack and tailpipe gases that trap heat, and while curbs in emissions can limit risks, vulnerable regions must adapt to shifting weather patterns and rising seas, top climate experts said Friday।

The conclusions came in the latest report from the Intergovernmental Panel on Climate Change, which has tracked research on human-caused global warming since it was created under UN auspices in 1988।

In February, the panel released a report that for the first time concluded with 90 percent certainty that human actions were the main cause of warming since 1950। But in this report, focusing on impacts of warming, the group described for the first time how species, water supplies, ice sheets, and regional climate conditions were already responding.

(The report can be found at www।ipcc.ch.)

At a news conference capping four days of debate between scientists and representatives from more than 100 governments, Martin Parry, the co-chairman of the team that wrote the new report, said widespread impacts were already measurable, with much more to come

"We're no longer arm waving with models," said Parry, who identified areas most affected as the Arctic, sub-Saharan Africa, small islands and Asia's sprawling, crowded, flood-prone river deltas

"This is empirical information on the ground"

The report said that climate patterns were shifting in ways that would bring benefits in some places - including more rainfall and longer growing seasons in high latitudes, opening Arctic seaways, and reduced deaths from cold - but significant human hardship and ecological losses in ओठेर्स.

The panel said the long-term outlook for all regions was for trouble should temperatures rise by 1।5 to 2.5 degrees Celsius, or 3 to 5 degrees Fahrenheit, with consequences ranging from the likely extinction of perhaps a fourth of the world's species to eventual inundation of coasts and islands inhabited by hundreds of millions of people.

The worst outcomes faced regions that are mainly poor and already facing dangers from existing climate and coastal hazards, let alone what might be worsened by human-caused warming, authors said.

"It's the poorest of the poor in the world, and this includes poor people even in prosperous societies, who are going to be the worst hit," said Rajendra Pachauri, the chairman of the panel and an energy expert from India.

'People who are poor are least equipped to be able to adapt to the impacts of climate change and therefore in some sense this does become a global responsibility in my view."

The report, written by hundreds of scientists and reviewed by outside experts and government officials, warned that adaptation is essential because decades of rising temperatures and seas are already inevitable due to the buildup of carbon dioxide and other long-lived greenhouse gases in the atmosphere. But it said that efforts to reduce emissions, could reduce, delay or avoid some harmful outcomes.

Final details were completed by hundreds of scientists here on Friday and approved by officials from more than 100 countries.

Some authors said the report removed any doubt about the urgency of acting to curb emissions of greenhouse gases.

"The warnings are clear about the scale of the projected changes to the planet," said Bill Hare, an author of the impacts report and visiting scientist at the Potsdam Institute for Climate Impact Research in Potsdam, Germany. "Essentially there's going to be a mass extinction within the next 100 years unless climate change is limited," added Dr. Hare, who previously worked for the environmetal group Greenpeace.

"These impacts have been known for many years, and are now seen with greater clarity in this report," he said. "That clarity is perhaps the last warning we're going to get before we actually have to report in the next IPCC review that we're seeing the disaster unfolding."

James Connaughton, the chairman of the White House Council on Environmental Quality, said some of the findings in the report, particularly the prospect of intensifying coastal damage from rising seas, were "of great concern," but noted the panel also foresaw benefits to agriculture in temperate regions as well.

Overall, he said, the analysis reinforced the importance of industrialized countries working to help developing countries cut their vulnerability to climate shocks by fostering their economic growth.

One of the most dramatic shifts in prospects laid out in the report is a projected overheating and parching of southern Europe, particularly in summer, and blossoming of northern regions.
But the report stressed that outsize threats would mainly face communities in Africa, the crowded river deltas of southern Asia, and low islands.

It also found that if investments are made to adapt to climate and coastal changes, some disruption and damage could be held at bay.

In one section, for example, the report projects the number of people who would be flooded out of homes by rising seas by 2080 under various scenarios for warming. A midrange level of projected warming by then could affect some 60 million additional people a year worldwide without adaptation efforts, but if investments in sea walls and other actions limiting flooding continued at the current pace, the number would drop to a few million a year.

"The actual outcome in terms of damages and ruined lives and costs depends heavily on the response - the response of individuals to deal with the changes and governments to organize and anticipate and deal with this in advance," said Michael Oppenheimer, a climate scientist at Princeton and an author of the report.

The meeting dragged on through Thursday night before Pachaui emerged Friday morning and announced that agreement had been reached over the final details of the 21-page summary.
Some authors said they were disappointed to see sections on hurricanes, some details on impacts, and outcomes under different emissions tracks removed or toned down under pressure from countries including Russia, China and Saudi Arabia. Officials from those countries argued that data in the underlying report did not support the level of certainty expressed in the final draft.

As a result, the final document was "much less quantified and much vaguer and much less striking than it could have been," said Stéphane Hallegatte, a participant from France's International Center for Research on the Environment and Development.

Another reason the meeting went through the night was because European delegates demanded that the final report reflect the need for cutting back on greenhouse gases - and not just adapting to new conditions.

"Adaptation will only work if climate change is not too large and not too fast," Mr. Hallegatte said.

The panel, created in 1988 and run under the auspices of the United Nations, has sometimes endured criticism for allowing governments to shape the summaries of its periodic reviews of climate science, which fill thousands of pages of reports.

But it remains, by many accounts, the closest thing to a barometer for tracking the level of scientific understanding of the causes and consequences of global warming.

Next month, the panel will release a report on options for limiting emissions of the greenhouse gases and late in the year it will publish a final synthesis report.


James Kanter reported from Brussels; Andrew C. Revkin reported from New York.

Link:
http://www.iht.com/articles/2007/04/06/healthscience/web-0406climate.php?page=2