No one can say we haven’t been warned.
In its final and most powerful report, a United Nations panel of scientists meeting here describes the mounting risks of climate change in language that is both more specific and forceful than its previous assessments, according to scientists here.
Synthesizing reams of data from its three previous reports, the United Nations Intergovernmental Panel on Climate Change for the first time specifically points out important risks if governments fail to respond: melting ice sheets that could lead to a rapid rise in sea levels and the extinction of large numbers of species brought about by even moderate amounts of warming, on the order of 1 to 3 degrees.
This report is apparently the “synthesis” of three previous documents from the IPCC. The first focused on the science, the second on how to adapt to climate change, and the third on how best reduce the greenhouse gases produced. This new report combines the lessons of all three, and points the way forward.
“This document goes further than any of the previous efforts,” said Hans Verolme, director of the World Wildlife Fund’s Global Climate Change Program. “The pressure has been palpable — people know they are delivering a document that will be cited for years to come and will define policy.”
What’s more, these dire risks have already been, if you’ll pardon the expression, watered down a bit. The language of the IPCC document was “reviewed and often altered by delegates from 130 governments who meet before their final approval and release,” including objections from the United States, China, India, and Saudi Arabia.
For its part, the Bush White House didn’t sound particularly concerned about quick action.
James L. Connaughton, chairman of the White House Council on Environmental Quality, said in an interview last night that the IPCC report “lays out a wide variety of mandatory and non-mandatory controls that deal with carbon emissions. These tools have varying effectiveness that varies from country to country. We have been careful not to prefer one tool over another, but to ensure that we are using the right tool.”
You can really sense the urgency from Connaughton, can’t you?
The IPCC report should, if there’s concern for reality at all, light a fire under policy makers.
One novel aspect of the report is a specific list of “Reasons for Concern.” It includes items that are thought to be very likely outgrowths of climate change that had been mentioned in previous reports, like an increase in extreme weather events.
But it for the first time includes less likely but more alarming possibilities, like the relatively rapid melting of polar ice. Previous reports focused more on changes the scientists felt were “highly likely.”
“This time, they take a step back and look at the totality,” Dr. Verolme said. “Saying it is less likely to occur, but if it does we are fried.”
One such area is the future melting of ice sheets in Greenland and western Antarctica. In earlier reports, the panel’s scientists acknowledged that their computer models were poor at such predictions, and did not reflect the rapid melting that scientists have recently observed. If these areas melt entirely, seas would rise 40 feet, scientists said. While scientists are certain that the sheets will melt over millennia, producing sea-level rises, there is now evidence to suggest that it could happen much faster than this, perhaps over centuries.
“In my view that would make it not just difficult, but impossible to adapt successfully, some of my colleagues would say catastrophic,” said Dr. Oppenheimer. “If they say that it’s possible that melting could occur in centuries leading to meters of change, that’s a headline.”
Stay tuned.