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Guest Post: A Big Deal on Climate?

[Daniel Bodansky is Foundation Professor of Law at Sandra Day O'Connor College of Law, Arizona State University.] Is the US-China joint announcement on climate change a big deal? Opinions differ widely. Paul Krugman says yes, Tyler Cowan, no. Who’s right? Is the announcement a “gamechanger,” as Joe Romm thinks, or “a well-timed, well-orchestrated press release,” as Cowan calls it? In part, the different answers reflect different measures of success, a point to which I will return in a moment. But, first, a little background. Back in 2011, the parties to the UN Framework Convention on Climate Change adopted the Durban Platform, which launched negotiations to develop a new legal instrument to limit global greenhouse gas emissions post-2020. The Durban Platform negotiations are to be completed and a new agreement adopted in December 2015 at the Paris conference of the parties. A decision adopted last year in Warsaw called on states to communicate their intended national contributions to the new agreement well in advance of the Paris meeting. What the United States and China unveiled in Beijing – although generally characterized as an “agreement” or “pact” – were their intended national emission targets under the 2015 agreement. At least four metrics are relevant in evaluating the joint announcement: First, do the announced targets put us on a pathway towards limiting climate change to safe levels? Safety involves value judgments, of course, but most scientists believe that warming of more 1.5-2° C above pre-industrial levels would result in dangerous impacts – impacts that most people would wish to avoid. (The earth is already about .8 degrees warmer than pre-industrial level, so we’re almost halfway there.) Even the most ardent boosters of the US-China deal don’t claim that, by itself, it will put the world on a 2° pathway, only that it is a first step. Second, do the targets announced by the United States and China represent a significant improvement over business as usual? Or, to put it differently, will achieving them require the US and China to significantly ratchet up their level of effort? Here, opinions differ widely, because they depend on judgments about what would happen in the absence of the targets, which in turn depend on assumptions about the economy, technology, and government policies more generally – all of which are highly uncertain. Who would have predicted, ten years ago, the Great Recession and the rapid expansion of fracking, both of which have had a huge influence on US emissions? So it is perhaps not surprising that some analysts say the US-China announcement “doesn’t change things much,” while others think it represents a major advance. Climate Interactive, for example, calculates that the US-China targets, if fully implemented, would reduce carbon dioxide emissions by about 650 billion tons through 2100 – and if other countries follow suit, taking similar targets, global emissions would be reduced by about 2500 billion tons through 2100. A brief sampling of estimates of Chinese and US emissions: