The Copenhagen diagnosis: sobering update on the science

The Copenhagen Diagnosis is not the first report to warn that climate change is occurring even more rapidly than had been predicted by the IPCC. Indeed, the UN itself has made this point. In September, the United Nations Environment Program released its Climate Change Science Compendium 2009. In the foreword of that report, UN Secretary General Ban Ki-moon noted that “climate change is accelerating at a much faster pace than was previously thought by scientists”. He warned: “Unless we act, we will see catastrophic consequences including rising sea levels, droughts and famine, and the loss of up to a third of the world’s plant and animal species.”

The Copenhagen Diagnosis is explicitly aimed at “policy-makers, stakeholders, the media and the broader public” on the eve of the international climate talks that begin on December 7. It takes up several questions of the sort not typically addressed in scientific forums, but frequently raised on the Internet and in the press. One of these is whether the Earth’s atmosphere is already saturated with carbon dioxide. The answer to this question, the report says, is “Not even remotely. It isn’t even saturated on the runaway greenhouse planet Venus, with its atmosphere made up of 96 per cent CO2 and a surface temperature of 467C.” Similarly, the report states, “global cooling” has not occurred over the past decade, “contrary to claims promoted by lobby groups and picked up in some media”. In fact, “even the highly ‘cherry-picked’ 11-year period starting with the warm 1998 and ending with the cold 2008 still shows a warming trend of 0.11C per decade,” the report concludes.

The report notes that in recent years, solar output has been at a low ebb. Meanwhile, warming has continued: “It is perhaps noteworthy that despite the extremely low brightness of the sun over the past three years temperature records have been broken during this time … The years 2007, 2008 and 2009 had the lowest summer Arctic sea ice cover ever recorded, and in 2008 for the first time in living memory the Northwest Passage and the Northeast Passage were simultaneously ice-free. This feat was repeated in 2009. Every single year of this century (2001-2008) has been among the top ten warmest years since instrumental records began.”

Konrad Steffen, a glaciologist at the University of Colorado who recently returned from taking measurements in Antarctica, said, “We as scientists wanted to make sure we provided all possible information. We tried to stay away from judgment calls - you wouldn’t believe the lengthy emails that we had - but on the other hand we wanted to make sure the urgency is there. We want to tell people it is urgent. We see changes that we did not anticipate two or three years ago.”

Gavin Schmidt, a NASA climate scientist who was not involved in The Copenhagen Diagnosis, said he thought the report was scientifically sound, but questioned whether it would have much impact on its target audience. “Knowing exactly how fast emissions are rising, or sea ice is melting, is useful and interesting, but my guess is that it will not have much effect on the delegates, since it doesn't address the actual equity and political issues that are at the heart of the slow movement towards an agreement,” said Schmidt.

Richard Somerville, of Scripps, acknowledged that scientific information - up-to-the minute or otherwise - was often ignored at climate negotiations.

“I’ve been to several of these meetings,” he said. “The delegates and the leaders say very kind things about the IPCC and thank it for its excellent work. But then, from a scientist’s point of view, once the negotiations start they might as well be negotiating, say, steel tariffs. I’ve actually heard politicians say - I won’t name any names - ‘We don’t want to be constrained by the science’.” But, he added, that only makes it more essential to get the information out.

“Not politicians and not money and not public opinion, but the climate system itself imposes a time scale,” Somerville said. “And if the world chooses not to stick within that, well, Mother Nature bats last.”