The principal one is carbon dioxide, but another one, methane, perhaps 20 times more effective as a greenhouse gas than CO2, must not be ignored.
Our natural gas is 90-plus-percent methane. By the way, it is plentiful in frozen permafrost, which poses a huge threat as the Arctic warms. Some also is released into the atmosphere by hydraulically fracturing, or “fracking,” shale rock.
A recent article in Chemical and Engineering News addressed its loss when fracking, which is the explosive attack on methane-containing shale layers.
That article spoke to the fairly low level of loss, as measured at the mine wellhead, but the article did note that the National Oceanic and Atmospheric Administration had found the loss to be 10 to 20 times higher, presumably from atmospheric measurements. I wrote a letter on this to C&EN, which has just been published. If NOAA’s numbers are correct, fracking is a serious source of greenhouse gas emissions.
I have seen no move to question the NOAA numbers and fracking. Why not? It may be that the money stakes are so high, as fracking has made a sea change in the availability of natural gas and its price. Where is our Department of Energy?
Can we conclude that big money will dictate our battle to control the livability of our planet? If the NOAA numbers are correct, replacing coal with gas from fracking in generating electric power will add to, not reduce, our greenhouse. Fracking itself is a serious source of increasing greenhouse gases, and should be banned.