11) We reached a tipping point in the fight against climate change

Three big things happened in climate change politics this year. The first is that 2015 looks set to be the hottest year on record. That means that temperatures have now risen by 1°C since the industrial revolution. The five-year period between 2011 and 2015 is also the hottest on record; and as the records tumble, the claims of climate change denialists are becoming increasingly ridiculous. We’ve turned the corner; climate denial is no longer being taken seriously. The world has moved on, and contrarians have become irrelevant relics of the fossil fuel age.

The second thing is that thanks to sharp declines in Chinese coal burning and a continued surge of renewable energy worldwide, 2015 looks set to be the first year ever that CO2 emissions declined during a year when the overall global economy grew. That follows from 2014, where emissions flatlined. The Chinese data is particularly important. Whether their energy transition is permanent is not clear yet, but the signs are encouraging. In wealthy, developed countries on the other hand, the signs are obvious. They’ve hit a peak in overall fossil fuel consumption and are now making the transition to cleaner forms of energy.

The third, and most important thing that happened for climate change this year was the signing of the Paris Agreement. At its core is a so-called ‘long-term goal’ that commits almost 200 countries to hold the global average temperature to below 2°C above pre-industrial levels and to “pursue efforts to limit the temperature increase to 1.5°C”. The long-term goal also states that in the second half of this century the world should get to a point where the net emissions of greenhouse gases should be zero.

Sure, it isn’t good enough. There’s a long way to go before the pledges match up to that target. But it’s still a lot better than expected, and a triumph for diplomacy. The largest gathering of world leaders ever, on the biggest issue humanity has ever faced, and it ended in a legally binding instrument that all countries agreed to. Jonathan Chait sums it up perfectly: