carbons emissions contributing to climate changeThe general scientific consensus is that the average global temperature cannot be allowed to warm more than two degrees Celsius [3.6°F] in order to avoid catastrophic climate change. In fact, a two degree rise alone would threaten the water supplies of hundreds of millions of people, lead to global crop declines, bleach coral reefs around the world, and drive up ocean acidification.

Limiting global emissions between 2010 and 2050 to 1,050 gigatons of CO2-equivalent pollution should give us a 75 percent chance of staying under a two degree rise, according to a new report from Ecofys and Greenpeace, which rounded up 14 “carbon bombs” — the biggest coal, oil and natural gas projects currently being planned around the world.

According to the analysis, the combined effect of these projects alone would dump 300 new gigatons of carbon into the atmosphere by 2050. That would blow through roughly a third of the allowance that gives us a 75 percent chance of staying under two degrees. Needless to say, if these projects were carried out, it would make it vastly more difficult for the planet to stay on a path that keeps it under the two degree threshold.

Two of the projects can be found in the United States, and a third is deeply bound up with rapidly approaching U.S. policy choices:

  • A plan to export new coal from the Pacific Northwest. This would add 420 million tons of carbon a year by 2020. Activists and even some American politicians have already been battling the project for some time.
  • Expanded shale gas production. This will add 280 million tons a year by 2020 according to the report. But as David Roberts points out, this estimate relies on the assumption that natural gas fields leak methane at a rate of 3.9 percent. There’s evidence that assumption significantly low-balls the problem.
  • Tar sands in Canada. This project would be greatly helped along by construction of the Keystone XL pipeline through the lower-48 states. The Obama Administration will decide whether to approve the pipeline sometime after March.

Here’s a map of the offenders, put together by The Washington Post‘s Brad Plumer from the report. (Click the image for a larger version.)

global co2 emissions contributing to global warming

The two biggest offenders in the report were China’s plan to ramp up new coal production, creating an additional 1,400 megatons of CO2 emissions a year, and Australia’s plan to export 760 new megatons of coal per year. Ironically, both countries were hit by the effects of coal pollution over the course of 2012. Particulate pollution in Beijing literally broke the relevant measuring scales, and Australia was wracked by a record-breaking heat wave and a rash of wildfires, all linked to global warming.

There is some good news in the caveats, as Plumer notes. The energy produced by these projects won’t necessarily add on linearly to each other, or to the energy already being produced by fossil fuels. Natural gas from one project could undercut the need from coal from another project, for instance, or it could displace coal consumption already occurring — a net reduction in carbon output, in the latter instance. (Of course, these projects could also displace energy being produced from renewables. A problem, to put it mildly.)