Hanger Responds To New Climate Change Study

Former Department of Environmental Protection Secretary John Hanger digs into a new study on climate change impact of replacing coal with natural gas, over at his “Facts of the Day” blog:

The article apparently concludes that replacing 50% of coal with gas would have a small impact on rising temperatures for this century.  But so would replacing 50% of coal with renewables or nuclear.
The carbon loading of the atmosphere is already significant and no one action or technology or energy choice short of sucking carbon out of the atmosphere is going to cut quickly or substantially the confirmed rising temperatures.

It probably is true that replacing coal with gas, renewables, energy efficiency, or nuclear–all of which do not load the atmosphere with particles–removes the cooling forcing provided when coal does put sulfates and particles in the atmosphere.  That impact of removing the cooling forcing of particles by itself raises temperatures in the short to medium run or the upcoming decades.
Of course a key point is that renewables, nuclear, energy efficiency as well as gas are cleaner than coal (renewables are the cleanest by a lot) but as a result all would remove the cooling forcing and so have the paradoxical effect Wigley notes.
The study has not been published and I have not read it, but assumptions matter in every study.  It seems that the study assumes that gas replaces just 50% of coal.  Why not run the models with a 100% replacement to see what the impact would be of removing even more carbon pollution and more particle pollution?

Editor's Picks