The US really has to get out in front. We are the biggest per person, by a substantial amount, greenhouse emitters, and we give the most foreign aid, not per person but in absolute.
We have built a greenhouse, a human greenhouse, where once there bloomed a sweet and wild garden.
The greenhouse effect is something you can observe experimentally - and most people have observed the greenhouse effect themselves, in greenhouses. Yes?
You could warm Mars up, over time, with greenhouse gases.
Who loves a garden loves a greenhouse too.
Even if we were to stop putting out greenhouse gases right now, we'd still face decades of warming.