The official position of planet Earth at the moment is that we can’t raise the temperature more than two degrees Celsius.
Some context: So far, we’ve raised the average temperature of the planet just under 0.8 degrees Celsius, and that has caused far more damage than most scientists expected. (A third of summer sea ice in the Arctic is gone, the oceans are 30 percent more acidic, and since warm air holds more water vapor than cold, the atmosphere over the oceans is a shocking five percent wetter, loading the dice for devastating floods.)
Scientists estimate that humans can pour roughly 565 more gigatons of carbon dioxide into the atmosphere by midcentury and still have some reasonable hope of staying below two degrees.
We’re not getting any free lunch from the world’s economies, either. With only a single year’s lull in 2009 at the height of the financial crisis, we’ve continued to pour record amounts of carbon into the atmosphere, year after year. In late May, the International Energy Agency published its latest figures – CO2 emissions last year rose to 31.6 gigatons, up 3.2 percent from the year before.
- America had a warm winter and converted more coal-fired power plants to natural gas, so its emissions fell slightly
- China kept booming, so its carbon output (which recently surpassed the U.S.) rose 9.3 percent
- Japanese shut down their fleet of nukes post-Fukushima, so their emissions edged up 2.4 percent.
Keep reading: Rolling Stone - Global Warming’s Terrifying New Math