Why is it the US needs to be the leader in climate change, when China has far surpassed us in global CO2 emissions?
The three big dogs are similar sizes economy wise, China is ahead of the US in some calculations:
GDP of USA: $18 trillion
GDP of European Union: $16 trillion
GDP of China: $14 trillion
The reality is that CO2 emissions by US and Europe are going down every year as emissions rise every year from the rest of the world:
So again I ask... what exactly do you want the US to do?
I am not blaming China, they manufacture goods for the rest of the world now so obviously they have taken on that burden (and economic boom) but it seems weird to say "Hey America, you need to fix this!" while the reality is that the solutions, impacts, and issues are almost entirely within Asia at this junction.
Stuff like the UN Green Climate Fund is ok I guess, its been running for a few years fund raising but it basically is just moving money from western countries and giving it to poorer countries and hoping something magic happens. There aren't any concrete fixes and no magic bullet that will somehow make fusion power plants arise. Solar and wind tech is progressing at a decent clip but its only now reaching the cusp of competitive with coal and gas, and not much government can do to speed that up.