Wedges reaffirmed

Robert Socolow in Bulletin of the Atomic Scientists:

Let's review the messages in our 2004 paper in Science. The paper assumes that the world wishes to act decisively and coherently to deal with climate change. It makes the case that “humanity already possesses the fundamental scientific, technical and industrial know-how to solve the carbon and climate problem for the next half-century.” This core message surprised many people, because our paper arrived at a time when the Bush administration was asserting that, unfortunately, the tools available were not suited for addressing climate change. Indeed, at a conference I attended at that time, Energy Secretary Spencer Abraham insisted that a discovery akin to the discovery of electricity was required.

Our focus on “the next half century” was novel; the favored horizon at the time was a full century — and still is. We argued that “the next fifty years is a sensible horizon from several perspectives. It is the length of a career, the lifetime of a power plant, and an interval whose technology is close enough to envision.”

In a widely reproduced Figure (see below) we identified a Stabilization Triangle, bounded by two 50-year paths. Along the upper path, the world ignores climate change for 50 years and the global emissions rate for greenhouse gases doubles. Along the lower path, with extremely hard work, the rate remains constant. We reported that starting along the flat emissions path in 2004 was consistent with “beating doubling,” i.e., capping the atmospheric carbon dioxide concentration at below twice its “pre-industrial” concentration (the concentration a few centuries ago).

More here.