Expanding Wedges: a News Roundup

April 2, 2008 |

A new piece in Nature today shatters the notion that we already have all the technology we need to deal with climate change. "Dangerous Assumptions" reveals that the United Nations Intergovernmental Panel on Climate Change underestimated the size of the technology challenge; it's at least twice as large as the world has come to believe.

The IPCC analysis of climate policy assumes that over three quarters of the emissions reductions required for stabilization will occur "spontaneously" -- without any policy incentives. While this has been the case in the U.S. and Europe, fast-developing nations like China and India are more reliant on coal than ever; worldwide, we are emitting more carbon, not less. Elizabeth Kolbert explains this trend in the New Yorker:

In the "business as usual" scenario that Socolow uses, it is assumed that decarbonization will continue. To assume this, however, is to ignore several emerging trends. Most of the growth in energy usage in the next few decades is due to occur in places like China and India, where supplies of coal far exceed those of oil or natural gas. (China, which has plans to build five hundred and sixty-two coal-fired plants by 2012, is expected to overtake the U.S. as the world's largest carbon emitter around 2025.) Meanwhile, global production of oil and gas is expected to start to decline -- according to some experts, in twenty or thirty years, and to others by the end of this decade. Hoffert predicts that the world will start to "recarbonize," a development that would make the task of stabilizing carbon dioxide that much more difficult. By his accounting, recarbonization will mean that as many as twelve wedges will be needed simply to keep CO2 emissions on the same upward trajectory they're on now. (Socolow readily acknowledges that there are plausible scenarios that would push up the number of wedges needed.)

It appears that the IPCC was aware of this recarbonization trend, but chose to downplay it in its "Summary for Policymakers." The result is that current proposals in Congress to deal with global warming are based on scenarios that radically underestimate the technology gap. "Dangerous Assumptions" makes clear that we do not have all the technologies we need to do reduce emissions, and we need a much larger national commitment to energy technology.


On the IPCC's Misrepresentation:

- "Dangerous Assumptions"

- Breakthrough's FAQ on "Dangerous Assumption"

On Stabilization Wedges:

- Interview with Physicist Marty Hoffert

- "The Climate of Man," Elizabeth Kolbert, the New Yorker


In addition to the technological issues, we also need new regulatory models and better public buy-in. With so much local opposition to WHICHEVER facility gets proposed (e.g., power plants, windmills, transmission lines, etc.) it will be difficult to changeover technologies quickly.

By R Margolis on 2008 04 03