If it is a fake, I retract and apologize.
For a long time it fooled me, too. Now I reply every time I see it posted on FR. Gotta maintain our credibility.
It could have been real. The left really did go through a "We're all gonna freeze!" phase before deciding that "We're all gonna fry!" was scarier.
I have to hand it to them, the fake Time cover is quality propaganda.