About 531 billion metric tons of carbon have been emitted by burning oil, coal and gas, cutting down forests and making cement since 1750, the UN said today. Capping greenhouse gas output at 840 billion tons gives a 50 percent chance of meeting the UN target of restraining warming below 2 degrees Celsius (3.6 degrees Fahrenheit), it said in its first such estimate.
Writing at New Scientist, Michael Le Page has a blunter summation: “Here, in 10 words, is the bottom line: we have to leave most fossil fuels in the ground. It really is that simple.”
In light of this, it’s worth revisiting one of the more interesting schemes for doing this in recent years.