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Sep 17, 2015

A Victory of the Commons

Can collaborative climate actions rescue the stalled international response to climate change? A series of new reports crunch the numbers to find out.
A sustainability officer maintains a pilot solar thermal water heating installation at Hong Kong's Science and Technology University. Photo by Jiri Rezac/The Climate Group, CC BY-NC-SA 2.0

In Iowa, wind turbines tower over wheat fields, brigades in an under-the-radar battle for power production dominance in the Hawkeye State. Satellite photos track solar panels’ steady expansion over the Gobi Desert, adding renewable power to China’s ballooning energy mix. And come October, commuters on London’s route 16 will ride double-decker buses that run on electricity instead of gas.  

These kinds of local and regional climate actions are multiplying rapidly. State energy plans and city transportation systems focus on projects that meet environmental, social, and economic bottom lines. The private sector has also awoken to the climate opportunity: the number of companies tracking their climate action has grown twenty-fold in the last 11 years, according to the CDP.

Climate activists hope this groundswell of climate action will help the world reach the level of ambition scientists say is necessary to avert climate change’s worst impacts. If cities, regions, and businesses want to act, their involvement could help ease painful and time-consuming wrangling over national climate commitments, and ratchet up inadequate levels of national ambition. The tragedy of the commons could become a race to the top.

The Best of the Bottom-up

Talk is cheap, as the adage goes, but numbers say a lot. Do local climate actions add up to meaningful emissions reductions? In other words, do these efforts show up when you zoom out?

Policy and climate analysts are working overtime to answer these questions. Commitment platforms overlay and organize more than 20,000 commitments to climate action. Many of these platforms, however, lack an easy or automated way to calculate how much these initiatives reduce global greenhouse gas emissions.

This information can make or break a climate commitment’s credibility. Without clear data, it is difficult to gauge a pledge’s ability to narrow the emissions gap between committed greenhouse gas reductions and the additional cuts needed to cap global temperature rise at 2 degrees Celsius. Scientists have warned that crossing this threshold will unleash climate change’s most destructive and costly impacts.

Four recent reports aim to fill climate commitment data gaps. In an analysis published in Nature Climate Change (and summarized in Grist) this May, a team from Yale University summed the emissions reductions of commitments made at last September’s New York Climate Summit. The pledges that resulted from this meeting could, in total, reduce 2020 emissions by 2.5 Gt, an amount roughly equal to India’s emissions in 2012. This would cut the 2020 emissions gap by approximately one quarter, bringing the goal of capping global temperature rise at 2 degrees Celsius within much closer reach.

A new study by the United Nations Environment Programme (UNEP) casts a slightly larger net, assessing 15 of the most ambitious and specific commitments from the Climate Initiatives Platform. These pledges could cut 2020 emissions by 2.9 Gt, narrowing the emissions gap by nearly one third.

Ecofys and the Cambridge Institute for Sustainability Leadership also explored the Climate Initiatives Platform, quantifying the emissions reductions potential of five high-impact private sector initiatives. The Cement Sustainability Initiative, en.lighten, Tropical Forest Alliance 2020, Refrigerants, Naturally! and WWF Climate Savers Program engage the cement, lighting, forest products, and refrigeration sectors, and help companies shrink their carbon footprints.  

At their current level of ambition, these initiatives could cut 2020 greenhouse gas emissions by 200 Mt. However, their impact could grow to 500 Mt, an amount equivalent to the yearly emissions of 131 coal-fired power plants, if they were to be scaled up rapidly.  

The final report, from the New Climate Economy, tallied the impact of climate actions across 10 global sectors, ranging from shipping and aviation to agricultural productivity. It honed in on strategies that could yield strong economic and environmental returns on investment.

The report finds that capitalizing on these opportunities could reduce emissions by 21 Gt (within a range of 16 - 26 Gt) by 2030, an amount roughly twice China’s 2012 emissions. Put another way, by 2030 these actions could achieve at least 59 percent, and as much as 96 percent, of the emissions reductions needed to keep global warming below 2 degrees Celsius.

What Can’t Be Measured

This promising news comes with two big caveats. The new reports risk both over- and under-estimating the groundswell’s impact on the world’s carbon budget.

The Nature Climate Change analysis, for instance, assessed the emissions impact of just 8 out of the Climate Summit’s 29 initiatives, since most lacked specific data on their targets. In June, The Climate Group analyzed The Compact of States and Regions, one of the Summit pledges left out of the Yale team’s assessment. They found that the Compact’s 20 participating governments represent over 220 million people, a population roughly equivalent to Brazil’s. This coalition also accounts for $8.3 trillion USD in GDP, or about 10 percent of the world’s economy, and emits 1.8 Gt of greenhouse gases each year – approximately twice Germany’s annual emissions. Emerging initiatives like the Compact could lower carbon emissions even further than the new reports anticipate. 

But implementing ambitious, game-changing climate initiatives will depend on money and on measurement. The Yale and UNEP analyses note a wide range of different monitoring strategies, and flag many vague funding and implementation plans. If partners in these initiatives fail to take on these challenges, the groundswell will fall short of its potential.

To move forward, bottom-up and top-down climate change initiatives will need to take a page from each other’s book. Success will require building a common framework for assessing city, state, and business initiatives, and bringing practical solutions to grand global goals.


Abbie Baertl, a graphic designer at the Yale Environmental Performance Index (EPI), created the infographic, with assistance from Chendan Yan, a Masters of Environmental Management candidate at the Yale School of Forestry & Environmental Studies. Megan Majd, a John Gardner Fellow at the Natural Resources Defense Council (NRDC), provided research assistance. Carlin Rosengarten, a staff writer and editor at the Yale EPI, reviewed and edited the document. We also thank Brendan Guy of NRDC for his support and feedback.