Carbon Dioxide?
Not tremendously surprising in content - I still remember three separate discussion I had with folks in my circle where I tried making the same point following another piece I read a year ago in, of all places, Car & Driver, and some personal research it sparked me to do, and just how violently all three people reacted to the idea that Carbon Dioxide may have nothing to do with global warming - but where it's coming from and the implications are... well... pretty big.