In Houston, the problem was not heat absorbed by asphalt. The problem was making flooding worse by covering a flood plain with asphalt. Trees help, but, in the long run, it's about reducing CO2 emissions, which is what the Paris Climate Accord was about. And adhering to it is only voluntary, making Trump's withdrawal all the dumber. And it remains to be seen to what degree the development of man made CO2 extraction technology will mitigate warming caused by CO2 emissions. I don't think anybody expects the modest goals of the Paris Accord to be met, anyway. As far as I am concerned the denial movement that attacks climate science is in part driven by fossil energy companies motivated by profit over the long term needs of humanity, and the general anti-intellectualism of popular culture, which distrusts authority in virtually all fields of human knowledge. As I've mentioned elsewhere, if not on this forum, I would not entrust brain surgery to a man off the street, but we're trending in that direction. And that's only partly comic sans....