Hello, cool world

摘要

Ecstatic celebrations broke out in Paris just before Christmas. World leaders acclaimed their freshly forged deal to fight climate change. There were hugs and tears. But hold on a second. Were the celebrations justified? The Paris agreement says governments will find a way to limit global warming to "well below 2 ℃" and do their darndest to have no more than 1.5 ℃. Is that even possible? Aiming for 1.5 ℃ is definitely a good idea, since two degrees of warming will almost certainly wipe low-lying islands off the map (see "1.5 ℃ versus 2 ℃", page 33). According to some climate scientists, it is also an impossible goal. Others are more optimistic, and think 1.5 ℃ might just be within reach. Just. One thing is clear: if we are going to do it, we will have to create a whole new industry to suck vast quantities of carbon dioxide directly from the air. Without these "negative emissions" we can bid farewell to 1.5 ℃.