The urban heat island effect is real, but modest warming since 1860 due to recovery from the little ice age is real also. About .1 degree per decade. It is not a problem, but mostly a benefit. The alarmists will not publicize real data because it is infinitesimal compared to the dire catastrophes they predict. They rely on computer models, which have never been able even to postdict accurately, and never will. And their predictions of doom have yet to come to pass.
Most importantly for political reasons, there is no correlation between CO2 level in the atmosphere and “average global temperature.” While CO2 level has been increasing on a gradual straight line, greening the earth as it rises, temperatures have fluctuated up and down significantly over the last 100 years. That alone should dismiss the whole ball of wax from serious consideration.
One thing about these models. If they are so wonderful, how come we never hear about how accurate they are when run backwards?