A 4th Climate Warning. Anyone Listening?

November 16, 2007, 11:01 pm

By Andrew C. Revkin

It was the culmination of an extraordinary meeting on the human-changed atmosphere. For three days, scientists had described how a buildup of long-lived gases emitted by burning fuels and forests would, if it continued, raise temperatures, raise seas and disrupt weather patterns important to agriculture, water supplies and wildlife. As the conference concluded, a leader of the group, Michael McElroy of Harvard, stood and said this: “If we choose to take on this challenge, it appears that we can slow the rate of change substantially, giving us time to develop mechanisms so that the cost to society and the damage to ecosystems can be minimized. We could alternatively close our eyes, hope for the best, and pay the cost when the bill comes due.”
That was June 1988. Dr. McElroy’s statement was the kicker on my first long story on global warming, which ran on the cover of Discover magazine a few months later.

Meltwater flows from the Kangerlussuaq Glacier in Greenland. (Credit: Andrew C. Revkin)
That year also saw the birth of the Intergovernmental Panel on Climate Change. Tonight in Valencia, Spain, the panel completed the final summary section of its latest review of what is known, possible and still a mystery about how human activities are influencing Earth’s climate and what we might do about it.
This was the fourth such review since 1990. Progressively over that span, the panel’s reports have raised the likelihood that people, mainly by burning billions of tons of coal and oil, have been the main force responsible for global warming since 1950 and that a lot more warming, coastal retreats and shifting weather are in the offing under business as usual. (In the bargain we get some plankton-harming ocean acidification, something not anticipated originally).
The rituals surrounding the release of these reports have always been the same. Around 10:30 p.m. local time on Friday in Valencia, according to my colleague Elisabeth Rosenthal, applause rang out when Rajendra K. Pachauri, the chairman of the panel, declared the fourth assessment completed after government officials approved the wording in a final concluding document. (There’ll be more applause in early December in Oslo when he and others snag half of the Nobel Peace Prize for nearly 20 years of painstaking, unpaid, exhausting, contentious work.)
As they always have, news services began describing the embargoed findings earlier in the evening, prodded by environmental campaigners and some scientists who hoped the results would inspire diplomats preparing to gather next month in Bali for the latest round of climate-treaty talks. Industry-backed groups issued their own news releases playing down the notion that new climate perils had been identified.
On Saturday governments will issue formal statements, each seeking to spin the findings to suit its own agenda and needs.
But the central question remains largely as it was posed by Dr. McElroy 19 years ago: Will the world’s leaders and citizens act on the basis of this building picture of a world sent into environmental flux by human actions, or choose to wait for some future round of research to clarify things a bit more?
In the meantime, the world is heading toward nine billion people, all seeking comfort and security and prosperity. A broad range of experts, within and outside the I.P.C.C., agree that sufficient energy to enable such progress (without overheating Earth) will come only with a mix of more efficient use of fossil fuels and fundamentally new energy technologies that do not influence the climate.
In essence, this challenge reflects a question I posed on Nov. 9, in a post called “What Does the Present Owe the Future“? As you can see from reader comments, there is no easy answer.
Many of the scientists involved with this marathon effort have spent more than half their lives trying to clarify what may come from what Roger Revelle, in an understated line, described in a 1957 paper as a “large scale geophysical experiment.”
In an e-mail exchange during a break in the proceedings today, Stephen H. Schneider, a Stanford University climatologist who has been in the climatology trenches since long before I quoted him in that 1988 article, put it this way (while declining to discuss the still-embargoed report): “The world learns slowly, so we keep moving forward haltingly, with backsliding, and do the best we can.”

U.N. Report Describes Risks of Inaction on Climate Change

Global Warming

Subhankar Banerjee/Associated Press
On Feb. 2, 2007, the United Nations scientific panel studying climate change declared that the evidence of a warming trend is "unequivocal," and that human activity has "very likely" been the driving force in that change over the last 50 years. The last report by the group, the Intergovernmental Panel on Climate Change, in 2001, had found that humanity had "likely" played a role.
The addition of that single word "very" did more than reflect mounting scientific evidence that the release of carbon dioxide and other heat-trapping gases from smokestacks, tailpipes and burning forests has played a central role in raising the average surface temperature of the earth by more than 1 degree Fahrenheit since 1900. It also added new momentum to a debate that now seems centered less over whether humans are warming the planet, but instead over what to do about it. In recent months, business groups have banded together to make unprecedented calls for federal regulation of greenhouse gases. The subject had a red-carpet moment when former Vice President Al Gore's documentary, "An Inconvenient Truth," was awarded an Oscar; and the Supreme Court made its first global warming-related decision, ruling 5 to 4 that the Environmental Protection Agency had not justified its position that it was not authorized to regulate carbon dioxide.

By ELISABETH ROSENTHAL
Published: November 17, 2007

VALENCIA, Spain, Nov. 16 — 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.
The report carries heightened significance because it is the last word from the influential global climate panel before world leaders meet in Bali, Indonesia, next month to begin to discuss a global climate change treaty that will replace the Kyoto protocol, which expires in 2012. It is also the first report from the panel since it was awarded the Nobel Peace Prize in October — an honor that many scientists here said emboldened them to stand more forcefully behind their positions.
As a sign of the deepening urgency surrounding the climate change issue, the report, which was being printed Friday night, will be officially released by Secretary General Ban Ki-moon on Saturday.
The full report was embargoed from news organizations until Saturday. But drafts have been circulating for weeks, and descriptions of its findings began to appear on Web sites and in news agency reports on Friday. Bush administration officials held a news conference to discuss the report but insisted that their comments be withheld until after its official release.
“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.”
The previous three sections, released between February and April, focused on one issue at a time: the first on science, the second on how the world could adapt to warming and the third about how countries could “mitigate,” or reduce the greenhouse gases produced.
This fourth and final assessment — the so-called synthesis report — seeks to combine lessons from all three. Its conclusions are culled from data contained in the thousands of pages that were essentially technical supplements to the panel’s previous publications. How that data is summarized and presented to the world is a powerful guide to what the scientists consider of utmost importance at the end of a five-year process, offering concrete guidelines for policy makers.
“You look to a synthesis report to provide clarity, to clarify what was obscure in previous reports,” said Michael Oppenheimer, a climate scientist at Princeton University. “Now, how can we take these findings and formulate a policy response that’s quick enough and big enough?”
While drafts of the panel’s reports are written by panels of scientists, the language is reviewed and often altered by delegates from 130 governments who meet before their final approval and release. Those negotiations took place here this week, and were often contentious, with the United States, China and India raising many objections, said scientists who spoke on condition of anonymity because they are not allowed to publicly refer to any countries by name.
The scientists and country representatives who had flocked here this week to participate in negotiations on the final wording applauded as the panel’s chairman, Rajendra Pachauri, declared the panel’s years of work concluded, just after 10:30 p.m. on Friday.
Even though the synthesis report is more alarming than its predecessors, some researchers believe that it still understates the trajectory of global warming and its impact. The I.P.C.C.’s scientific process, which takes five years of study and writing from start to finish, cannot take into account the very latest data on climate change or economic trends, which show larger than predicted development and energy use in China.
“The world is already at or above the worst case scenarios in terms of emissions,” said Gernot Klepper, of the Kiel Institute for World Economy in Kiel, Germany. “In terms of emissions, we are moving past the most pessimistic estimates of the I.P.C.C., and by some estimates we are above that red line.”
The panel presents several scenarios for the trajectory of emissions and climate change. In 2006, 8.4 gigatons of carbon were put into the atmosphere from fossil fuels, according to a study in the proceedings of the National Academy of Science, which was co-written by Dr. Klepper. That is almost identical to the panel’s worst case prediction for that year.

Andrew C. Revkin contributed reporting from New York.