What you really need is a way to turn heat into some sort of long term energy storage. What you'd need is something like a thermal->chemical energy converter.

What you really need is a way to turn heat into some sort of long term energy storage. What you'd need is something like a thermal->chemical energy converter. You could even make it do something useful, like desalinate water. However, good luck pulling enough thermal energy from the air or ocean to have any significant effect on global climate.