The Mauna Loa observatory reported last week that CO2 levels are now at four hundred parts per million, which means that we’ve “got more carbon dioxide in the atmosphere now than at any point since the Pliocene, when there were jungles in northern Canada.” Elizabeth Kolbert uses the milestone to argue against the Keystone pipeline:
Alberta’s tar sands contain an estimated 1.7 trillion barrels of oil. Assuming that only a tenth of that is recoverable, it’s still enough to generate something like twenty-two billion metric tons of carbon. There are, it should be noted, plenty of other ways to produce twenty-two billion metric tons of carbon. Consuming about a seventh of the world’s remaining accessible reserves of conventional oil would do it, as would combusting even a small fraction of the world’s remaining coal deposits. Which is just the point.
Were we to burn through all known fossil-fuel reserves, the results would be unimaginably bleak: major cities would be flooded out, a large portion of the world’s arable land would be transformed into deserts, and the oceans would be turned into liquid dead zones. If we take the future at all seriously, which is to say as a time period that someone is going to have to live in, then we need to leave a big percentage of the planet’s coal and oil and natural gas in the ground. These basic facts have been established for decades, and every President since George Bush senior has vowed to do something to avert catastrophe. The numbers from Mauna Loa show that they have failed.