I’m too young to know if this is true or not, but Ross Douthat gives the history:
To understand why, it’s worth going back to the 1970s, the crucible in which modern right-wing politics was forged.
The Seventies were a great decade for apocalyptic enthusiasms, and none was more potent than the fear that human population growth had outstripped the earth’s carrying capacity. According to a chorus of credentialed alarmists, the world was entering an age of sweeping famines, crippling energy shortages, and looming civilizational collapse.
It was not lost on conservatives that this analysis led inexorably to left-wing policy prescriptions — a government-run energy sector at home, and population control for the teeming masses overseas.
Social conservatives and libertarians, the two wings of the American right, found common ground resisting these prescriptions. And time was unkind to the alarmists. The catastrophes never materialized, and global living standards soared. By the turn of the millennium, the developed world was worrying about a birth dearth.
This is the lens through which most conservatives view the global warming debate. Again, a doomsday scenario has generated a crisis atmosphere, which is being invoked to justify taxes and regulations that many left-wingers would support anyway. (Some of the players have even been recycled. John Holdren, Barack Obama’s science adviser, was a friend and ally of Paul Ehrlich, whose tract “The Population Bomb” helped kick off the overpopulation panic.)
The full post can be found here.