While many people are traveling to Warsaw this week to participate in the international climate negotiations (COP 19), the city is also hosting another global conference: the International Coal and Climate Summit. It’s a troubling juxtaposition—coal contributes to 43 percent of global greenhouse gas emissions, making it a major driver of climate change. In fact, a new statement released by leading scientists suggests that nearly three-quarters of fossil fuel reserves—especially coal—must remain unused if the world is to limit temperature rise to 2 degrees Celsius. In other words, limiting sea level rise, extreme weather events, heat waves, and other climate impacts requires staying within world’s “carbon budget”—which doesn’t include unabated coal use.

The Carbon Budget

The statement comes on the heels of the Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report (AR5), which found that emissions related to human activities must not exceed 1 trillion tonnes C (1000 PgC) if we are to have a likely chance of limiting warming to 2°C. The world has already used up more than half of this “carbon budget,” and under a carbon intensive trajectory1, is on track to exceed it in about three decades.

Staying within our carbon budget also means living within a “fossil fuel budget.” According to the IPCC, limiting warming to 2 degrees C requires capping fossil fuel emissions at 270 PgC for the period between 2012 and 21002. Yet the new scientific statement says that CO2 emissions associated with reserves of coal, oil, and gas are 3,863 GtCO2, or 1,053 PgC. Therefore, burning through only 26 percent of these reserves would break the carbon budget, meaning roughly 74 percent of fossil fuels would need to remain unused to limit warming to 2 degrees C.

What Does this Mean for the Future of Coal?

The world’s “fossil fuel budget” holds the most significant implications for coal. Carbon dioxide emissions associated with burning coal are the greatest of any fossil fuel, and coal has the highest carbon content among all unburned fossil fuel reserves. Data from the scientific statement shows that we would need more than two fossil fuel budgets for the emissions associated with coal reserves alone, leaving no budget for continued use of oil or natural gas.

Despite these known risks, coal remains a dominant energy source. WRI’s Global Coal Risk Assessment found that there are nearly 1,200 new coal-fired power plants slated for development worldwide. More than three-quarters of these plants are proposed in India and China, nations already struggling with air quality and environmental issues associated with coal emissions, and coal remains an existing source in many countries.

The International Energy Agency (IEA) reports that coal currently provides 40 percent of the world’s electricity and has been the fastest-growing global energy source since 2000. The IEA’s most recent World Energy Outlook finds that while renewables and natural gas generation will grow rapidly, coal is still projected to be the dominant source of electricity through 2035.

Coal Is a Serious Threat to a 2 Degree C World

It’s time to start moving away from unabated coal use—and start transitioning to a low-carbon economy.

Encouragingly, renewable energy generation is already rapidly increasing around the world, driven by declining costs and progressive government policies that make clean energy cost-competitive with fossil fuels. As the scientific statement notes, 42 percent of all new electric generation capacity in 2012 was renewable energy.

COP 19 negotiators should play a key role in shifting from coal to a low-carbon future. It’s important that they make progress toward establishing an international climate agreement in 2015—one that’s ambitious enough to keep temperatures within the 2 degree C target. Countries can move this agreement forward in Warsaw by putting forth a process for delivering transparent and ambitious national emissions reductions offers. Securing an international climate agreement by 2015 is essential--it would send clear signals to investors to shift financing away from fossil fuels like coal and toward clean energy.


  1. Assumes RCP 8.5 scenario. ↩︎

  2. For the scenario most compatible with the 2°C target (RCP 2.6). ↩︎