Scientists from Princeton University and UC Irvine determined existing power plants across the globe will release 300 billion more tons of carbon dioxide over their lifetimes, adding to atmospheric levels of climate-warming gas.
These findings are the first to look at how quickly "committed" emissions are growing as even more fuel-burning plants are built; they are believed to be growing by about four percent per year.
"Bringing down carbon emissions means retiring more fossil fuel-burning facilities than we build," said Steven Davis, assistant professor of Earth system science at UCI and the study's lead author. "But worldwide, we've built more coal-burning power plants in the past decade than in any previous decade, and closures of old plants aren't keeping pace with this expansion."
"Far from solving the climate change problem, we're investing heavily in technologies that make the problem worse," he added.
Emissions from these existing power plants make up a substantial portion of the climate budget, which would keep global temperatures from warming more than two degrees Celsius from what they were during the preindustrial era.
Power plants in the United States and Europe contribute to 11 percent and nine percent of committed emissions, respectively; these commitments have been declining in past years, which calls attention to the rapid growth of China's power sector since 1995. Plants in China currently represent 42 percent of the world's committed future emissions.
About two-thirds of the emissions from the power sector are linked to coal-burning stations. Commitments related to natural gas-fired generators have risen from 15 percent in 1980 to 27 percent in 2012 since more of these plants are being used; natural gas plants emit less CO2 per unit of energy than coal. The findings could help policymakers evaluate the climate impacts of investments in these industries.
"We've been hiding what's going on from ourselves: A high-carbon future is being locked in by the world's capital investments," said co-author Robert Socolow of Princeton. "Current conventions for reporting data and presenting scenarios for future action need to give greater prominence to these investments. Such a rebalancing of attention will reveal the relentlessness of coal-based industrialization, long underway and showing no sign of abating."
