It was a big surprise to everyone, since the delegates arriving at the big UN climate conference in Cancun, Mexico, did so with such low hopes.
A year ago, they left Copenhagen feeling defeated, worried that the whole multilateral global approach to tackling climate change was doomed to failure.
A year went by. Unprecedented floods, fires and heat-waves came and went, exactly as the science of climate change predicted. The climate-deniers’ confidence that climate change was a conspiratorial fraud grew in leaps and bounds. In November, Americans elected a Congress dominated by Republican climate-skeptics.
So what happened to change everything?