Forest degradation and conversion are responsible for around 12 percent of overall greenhouse gas emissions — the majority of which is carbon dioxide released from forest fires and deforestation. (forestsnews.cifor.org)
But «will not lead to a net increase in overall greenhouse gas emissions» is quite specific, and powerful. (grist.org)
One way or another the oil will find a way to market, which means building Keystone won't raise overall greenhouse gas emissions at all relative to not building it. (grist.org)