“Climate researchers now predict the planet will warm by 6.3 degrees Fahrenheit by the end of the century even if the world’s leaders fulfill their most ambitious climate pledges, a much faster and broader scale of change than forecast just two years ago.” This analysis was conducted by the Climate Interactive project, led by climate scientist Dr. Robert Corell, the chair of the Heinz Center’s Climate Action Initiative. The researchers fed the possible commitments by the world’s nations for the global climate deal to be negotiated this December in Copenhagen, Denmark into a dynamic model that projects how the climate will respond:
We collected emissions reductions proposals in the public domain up until September, 2009 – and found that even if these were fully implemented they would be far from sufficient to meet the goal of stabilizing atmospheric CO2 levels at or below 350 ppm, reaching instead about 716 ppm CO2 and 944 CO2e by 2100. These proposals would not be sufficient to limit warming to 2°C over pre-industrial temperatures, creating instead approximately 3.5°C of temperature increase by 2100.
As top climate scientist Stefan Rahmstorf explained at the Copenhagen Climate Change Congress in March, even limiting global warming to two degrees Centigrade above historical levels — 1.3 degrees (2.3 F) above current temperatures — isn’t as safe as Russian roulette. However, the scientists behind the analysis recognize that taking action is dramatically better than business as usual. Andrew Jones writes that this finding could also be described in a positive light — “New Analysis Shows Growing Commitment to a Global Deal Will Help Stabilize Climate“:
Following the “current proposals” path is much better than “business as usual” path. Many countries have offered concrete proposals, others (like China) are looking more encouraging, and the results add up. About 3100 gigatons of CO2e would be kept out of the atmosphere between now and the end of the century, resulting in CO2 levels 239 ppm lower and the world a full degree C cooler by 2100 (3.5 degrees C vs. 4.5).
The leaders of the world’s top economies — and greatest polluters — are now meeting in Pittsburgh for the G-20 summit. The chair of the International Panel on Climate Change, Rajendra Pachauri, and Center for American Progress president John Podesta have now made a dramatic appeal to those leaders to “reflect this imperative” that “that temperatures should not be allowed to exceed 2 degrees Celsius and that, as a consequence, global emissions must be reduced 50 percent by 2050.”
The Climate Initiative analysis provides evidence that even that target is likely insufficient to keep warming below 2 degrees Celsius. The G-20 should accept scientific reality and recognize that the goals they are now debating represent a minimal effort to stave off planetary catastrophe.