Tomorrow, scientists and government officials will gather in Valencia, Spain, to put together the fourth and last United Nations report on the state of global warming and what it will mean to hundreds of millions of people whose lives are being dramatically altered.
Unlike the past three tomes, this one will have little new data. Instead, it will distill the previous work into a compact guide of about 30 pages that summarizes complex science into language that politicians and bureaucrats can understand.
It will be the first point of reference for negotiators meeting next month in Bali, Indonesia, to decide the future course of the worldwide push to curb greenhouse gas emissions after the 2012 expiration of the first phase of the Kyoto Protocol, the landmark agreement that assigned binding reduction targets to 36 countries.
On Friday, UN Secretary General Ban Ki-moon visited Antarctica to see firsthand the effects of climate change and the melting of glaciers. Ban flew from Chile's southernmost city of Punta Arenas to that country's station on Antarctica, the Eduardo Frei base, accompanied by officials and scientists. From there, he took a 45-minute flight over the region, seeing several glaciers.
The UN's new global warming report is the last of four issued by the Intergovernmental Panel on Climate Change. One of its authors, Bert Metz, of the Netherlands Environmental Assessment Agency, said it "integrates all the elements, the connections between them."
UN officials delayed the Bali meeting by several months until after the report is released, expecting it would add political momentum to the conference.
Though the Intergovernmental Panel on Climate Change was created in 1988 to assess the science of global warming, its work gathered a momentum this year that has helped reshape opinion in the public and governments.
In the ultimate validation, the panel's warnings on man-induced climate change shared the Nobel Peace Prize with Al Gore, former vice president, the world's best-known global warming campaigner.
"The reactions that I heard from politicians around the world is that they were shocked by the reports and that they should be acted on," said Yvo de Boer, the UN's top climate official.
The United States, Australia, and many developing countries that shunned the Kyoto treaty are now ready to begin discussing a successor agreement at the Bali conference, De Boer said.
"There is a growing consensus that Bali needs to achieve a breakthrough to put negotiations in place, and that's very encouraging," he said. "But it's not going to be a piece of cake."
Campaigners are looking for the final "synthesis report" to emphasize the action governments can take, the consequences of inaction and the brief time remaining to put that action into gear.