What you need is called an arbitrage.
Find a publicly traded investment that stands to go up if the predicted warming occurs.
Alternatively, you could short a publicly traded investment that stands to go down if the predicted warming occurs.
If you place your bets on global warming in any other way, then you really can't expect to be paid-off in the event of global warming occuring...
On other thing, keep in mind that the "general concensus" is that warming is already occuring. So that will already be factored into the price of your arbitage position should you buy one.