The evidence is from trees buried in the Eurasian tundra where it is too cold for them to grow today.

FORBES: Drowning Polar Bears And the Return Of Ursus Bogus

Even today it is clear that cold, not heat, is deadlier to human condition.

FORBES: The Black Death: Longing For The Good Old Days

Afterwards, of course, Mars became the cold, apparently lifeless, body that it is today.

ECONOMIST: Panspermia: Interplanetary migration | The

The political universe is, of course, very different today from what it was during the Cold War.

NEWYORKER: Confounding Fathers