There was an important development at yesterday’s Climate Summit in Copenhagen that should have gotten more attention in the media. There was also a data update that provides additional context for the importance of that development.
The island nation of Tuvalu wanted legally binding language to be written establishing limits in global atmospheric CO2 concentrations to 350 parts per million and global temperature rise to 1.5C above pre-industrial levels. For clarity, our current global CO2 concentrations, according to observations, is 387ppm. So we’re already above the limit that scientists have identified as being a threshold we should not be above if we don’t want global temperatures much higher than they are today. Tuvalu was asking, therefore, for nations to agree to reduce emissions drastically so that the atmospheric concentrations begin decreasing. Why would they want legally binding language for such an audacious goal? Because Tuvalu is a set of four reef islands and five atolls whose maximum elevation is 15ft. They are extremely susceptible to any future potential sea level rise. Larger, richer countries (like Saudi Arabia and China) would hear none of it. They want to keep burning dirty fossil fuels and expand their economies like other developed nations did for the past 150 years. Tuvalu and a group consisting of other island countries and poorer nations can’t afford to wait until China decides they’re ready to switch to 100% renewable energy at some point in the future. They’re at risk today from climate change that is already occurring. The issue was suspended for the time being. Expect it to arise again before the end of next week (not that a solution will be found in that time frame, unfortunately).
Which brings me to the bad news of the day. I’ve written for months now that the 2007 IPCC AR4 report was good for its time, but it left significant questions unanswered (I haven’t been the only one). It was good, but didn’t go far enough. Major drawbacks resulting from a far too conservative approach, an approach that didn’t examine extremes as likely enough to spend much time on. Since the collection of papers for the 2007 AR4 release, scientists across the world have worked very hard to try to begin finding answers for the toughest questions remaining. How sensitive is the climate to GHG emissions? How responsive are temperatures to those emissions? When will glaciers and ice sheets melt? What kind of sea level rise can be expected? Another paper was put together to try to answer that last question. As with other facets of the research effort, conditions could very well be much worse than what the 2007 Report may have led people to think:
Sea level rise could occur 3 times faster than previously estimated. Everybody should be able to click on the link and look at the pdf if they want. Here’s the high-level message: based on our current emissions profile, which is as high as the worst-case scenario the IPCC examined, sea levels could rise by 6 feet (~2m) by 2100. The rate at which sea levels have been rising has increased in the past 20 and 10 years. Scientists’ predictions of sea level rise have been too low, contrary to the denialists’ hopes otherwise. Natural causes alone have not and cannot explain the rise observed. Like I wrote above, Tuvalu and many other countries are under immediate threat. They have no more time to wait while rich countries throw tantrums like spoiled children. This situation is likely to get worse before it gets better.
My 9Dec2009 summary is here.
My 7Dec2009 summary is here.
Cross-posted at SquareState.