Many of the countries worst affected by climate change have contributed least to the emissions that cause it.
So where should the burden lie in taking action to counter it?
Reality Check's Chris Morris takes a look at some of the big questions at the heart of climate justice.
This is the crux of climate change - how do the richest members of society compensate the poorest for the adverse effects of climate change? And how can we compensate for historical emissions?
It seems that the developed world has fallen short in this regard.