Tuesday, September 29, 2015

News On Global Warming Is Better than Reported

All the major emitters except India have already announced the commitments to cut greenhouse gas emissions that they will bring to the Paris conference in December.

A group named Climate Interactive, associated with MIT, has analyzed the impact of these pledges. The New York Times had a discouraging article about this analysis, which said that without these pledges, there would be 8.1 degrees Fahrenheit of warming by the end of the century, and with the pledges, warming will be reduced to 6.5 degrees F. by the end of the century - far short of the world's goal of limiting warming to a total of 3.6 degrees F.

But a graph of Climate Interactive's projections shows that things are not as bad as they seem.

For about the next seven years, the pledges reduce total world emissions and keep emissions close to the pathway needed to limit warming to 3.6 degrees F.

Most pledges set goals for reductions by 2025 or 2030, and Climate Interactive projects so much warming by the end of the century, because it assumes that emissions will begin to grow again when these pledges expire. But that is unlikely: if the world can reach this agreement in Paris, then it is very likely that the world will be able to reach future agreements to keep reducing emissions for the rest of the century.

For the next seven years, we are almost on the path to limit warming to 3.6 degrees F.  As the world tools up to meet these initial goals, it is bound to develop new technologies that will make it easier and cheaper to reduce emissions in the future.

It looks like the Paris conference will be a good first step.  There will still be lots of work to keep setting more aggressive climate goals in the future. And the goal of 3.6 degrees F. itself is not ideal: we are now less than half way there, and we are already seeing effects of global warming ranging from drought and reduced snow packs in California to drought in Syria that has driven farmers off their land and contributed to the rise of ISIS.

Nevertheless, there is a real reason to hope, for the first time, that the world will be able to avoid catastrophic global warming.