The mean temperature of the earth is decided by the incoming solar energy minus the energy which radiates from the earth out into space.
The oil and coal we human beings started to use in a large scale during the 19th century release a constantly increasing quantity of gas to the air we breathe. Sorry to say, this activity -unknown to mankind before- doesn’t leave Earth as a radiation out into space. Consequence: the mean temperature in our atmosphere accumulates continually.
Anyway, does this matter? Yeah, it really does matter! By far all scientists postulate that the increasing temperature of the earth atmosphere initiates more and more severe weather catastrophes. And, as if that weren’t bad enough our both poles produce melt water as ever before. Forecast: the water level of the earth’s oceans will soar by meters within a few generations!
If we carry on as if nothing had happened ALL MANKIND will be hurt. Regardless of religion or political system and/or possession of weapons of mass destruction.