Mr Xi and Mr Obama run the two wealthiest countries in the world. The former is undemocratically elected and the latter elected by a very flawed democratic system. Both have power and can use their power for good or for evil.
Both China and the USA have been rather coy about limiting greenhouse gas emissions. China has refused to do anything that might slow down its economic growth and the USA has refused to do anything that might make it accountable to the rest of the world, so while many nations, particularly those in the European Union, make grandiose and mostly irrelevant pledges of future greenhouse gas reductions until now China and the USA have been silent.
Now they have spoken. Obama threatens a reduction of about 27% from 2005 levels by 2025 and China has said it will peak its emissions by 2020.
I think that we must not get over excited about Mr Obama and Mr Xi’s statements of emission reduction. They are unlikely to be met, as in each case if the choice is perceived as between reducing emissions and retaining power and wealth, reducing emissions will not occur. China and the USA produce four and a half times more greenhouse gas emissions than the whole of the European Union. The fate of the world, as far as climate change is concerned is firmly in their hands and I cannot say that I find any comfort in knowing that.