U.S., China Reach Historic Climate Change Agreement

Stunning and welcome climate change news came out of China on Tuesday, when President Obama and Chinese President Xi Jinping announced a historic joint climate commitment. The U.S. pledged to cut greenhouse gas emissions by 26 - 28% by 2025, compared with 2005 levels. In turn, China agreed to peak its greenhouse gas emissions by 2030--and sooner if possible--and to get 20% of its energy from non-fossil fuel sources by 2030. In order to achieve its part of the bargain, the U.S. will need to double the pace of carbon pollution reduction from 1.2% per year from 2005-2020 to 2.3 - 2.8% per year between 2020 - 2025. In order to achieve its part of the deal, China must deploy an additional 800 - 1,000 gigawatts of nuclear, wind, solar and other zero emission generation capacity by 2030--more than all the coal-fired power plants that exist in China today, and close to total current electricity generation capacity in the United States.   


Figure 1. U.S. President Barack Obama shakes hands with Chinese President Xi Jinping after a joint press conference at the Great Hall of People to announce a historic climate change deal on November 12, 2014 in Beijing, China. (Photo by Feng Li/Getty Images)

A step in the right direction, but a long ways to go
Humanity has a budget to keep. In order to keep global warming below the agreed-upon definition for the threshold of dangerous climate change, 2°C above pre-industrial levels, cumulative human CO2 emissions since 1870 must remain below about 2900 GtCO2. About two-thirds of that budget--1900 GtCO--had already been emitted by 2011, according to the November 2, 2014 IPCC Synthesis Report. The International Energy Agency warned in 2012 that "almost four-fifths of the CO2 emissions allowable by 2035 are already locked-in by existing power plants, factories, buildings, etc. If action to reduce CO2 emissions is not taken before 2017, all the allowable CO2 emissions would be locked-in by energy infrastructure existing at that time." If China and the U.S. follow their new commitments, humanity will exceed its carbon budget by 2042, just five years later than if they continue to follow their current "business as usual" course, according to analysis by Frank Melum, Senior Point Carbon Analyst at Thomson Reuters. “We do not expect these new targets to significantly alter the world’s trajectory for emissions growth, but the joint announcement will probably alter the pace of negotiations, and could in time could lead to improved ambition levels,” said Melum.


Figure 2. Of the proven fossil fuel reserves still in the ground (equivalent to emitting 2795 Gt of CO2, dark grey oval with a black oval of the maximum we can burn embedded in it), between 66% - 86% must stay in the ground if we are to have at least a two-in-three chance of keeping warming below 2°C, according to three groups who have done carbon budget analyses, the IPCC, the International Energy Agency, and the Carbon Tracker Initiative. Reserves are those quantities able to be recovered under existing economic and operating conditions (split as 63% coal, 22% oil, and 15% gas, according to the International Energy Agency.) These reserves were valued at $27 trillion (nearly 40% of the global yearly GDP), according to The Capital Institute. The IPCC, quoting Rogner et al., 2012, Global Energy Assessment–Toward a Sustainable Future (Chapter 7: Energy Resources and Potentials), says that these reserves are a factor of 4 - 7 more than what can burned. Fossil fuel resources are those where economic extraction is potentially feasible, and could become reserves in the future (e.g., methane hydrate deposits under the ocean floor.) The IPCC estimated these resources were an additional factor of 31 - 50 higher than the maximum we can burn. If only a small fraction of the these resources are developed and burned, Earth would have a hot-house climate like occurred during the age of the dinosaurs.

Commentary: A game-changing agreement
While the new deal is not binding and doesn't go far enough on its own to stop dangerous climate change, it is a huge political step forward in the fight against climate change. One of the key arguments being made in the U.S. against taking climate change action--that China was doing nothing to limit their emissions--has now been nullified. And over the next fifteen years, China is planning on installing enough renewable energy from sources like solar and wind to power the entire United States--guaranteeing continued explosive growth and price drops in green energy that will make it able to out-compete fossil fuels even with the massive subsidies they enjoy. When you add in last month's European Union (EU) pledge to cut total emissions 40 percent below 1990 levels by 2030, we now have countries representing more than half of all global emissions making serious commitments to reduce carbon pollution. This gives real hope that a significant binding treaty to limit greenhouse gases can be successfully negotiated in Paris in December 2015 at the critical ‪United Nations Climate Change Conference‬.

Links
U.S.-China Joint Announcement on Climate Change and Clean Energy Cooperation: White House Fact Sheet.

Why The U.S.-China CO2 Deal Is An Energy, Climate, And Political Gamechanger: November 12, 2014 blog post by Joe Romm at ClimateProgress.org.

IPCC Final Report: We've Blown Two-Thirds of Our Carbon Budget: my November 2, 2014 blog post.

What You Need to Know About U.S.-China Climate Pact: November 12, 2014 blog post by Brian Kahn of ClimateCentral.org.

Jeff Masters