Why are we so concerned with the minutiae of diesel engines, the availability of satellite maps, the disclosure of carbon emissions, and so forth? Because they all connect back to global warming-induced climate disruption: why it's happening, how we know about it, and what we can do about it. The results of continued rapid increases of levels of greenhouses gases in our atmosphere will be pretty awful -- world-changing, one might say, but in a bad way. But just how bad? How fast will they happen? And what are our best choices for mitigating the worst of it?
These were the questions asked at the "Avoiding Dangerous Climate Change" conference held in Exeter, UK, on February 1-3, bringing together around 200 climate scientists from around the world. Although the initial trigger for the conference was the need to define precisely what constituted "dangerous climate change," the scientists ended up instead detailing "critical thresholds that we should aim not to cross" -- a less dramatic phrase, but an approach more focused on science than policy. The conference covered three broad issue: an assessment of impacts, an examination of climate sensitivity and emission pathways, and what our technological options for mitigation will be. Impressively, the presentations from each of three days are already on the website for download. The Steering Committee report (PDF) summarizes the findings.
These are not easy reading, both because they are generally presentations written by climate scientists for climate scientists, and because the results they describe are, in a word, depressing. Some of the stories are filtering into the mainstream media -- the increased acidity of oceans (presentation here, PDF), the disappearance of Antarctic glaciers (presentation here, PDF), and the impact of global warming on poor nations, particularly in Africa (presentation here, PDF). An old favorite, disruption of the thermohaline flow leading to abrupt climate change, got a new examination (PDF), too. Getting less play, unfortunately, are the second day's discussions of climate sensitivity -- in effect, the "how fast is this happening" and the "how fast can we prevent it from happening" rolled into one -- and the final day's presentations outlining our options for avoiding worst-case scenarios -- the WorldChanging day, if you will.
All of the Technological Options presentations are worth looking at, but some are especially interesting:
It's unfortunate, but perhaps not terribly surprising, that the Exeter conference results have gotten very little play in the American media (outside of Alaska and a few science and environmental news sites). Ultimately more unfortunate, however, is the nearly exclusive focus on the dramatic dangers that global warming-induced climate disruption, if unchecked, will present. This tends to leave readers despairing or, worse still, resigned to our fate. But solutions are possible -- the tools are here, now. As Socolow notes in the conclusion of his presentation:
Can We Do It?
To stabilize [atmospheric carbon levels] below doubling will be disruptive.
But people are becoming increasingly anxious about our limited understanding of the experiments we are performing on the only Earth we have...
...and are learning that there are ways to live more cautiously.
We should anticipate a discontinuity:
What has seemed too hard becomes what simply must be done.