“irreversibly?” Really? The evidence does seem to indicate that the climate is getting warmer and less stable. It does seem to indicate that we’re behind it. I understand the concept of tipping points, and Greenland (to pick one aspect) is a really big chunk of ice to try to put back if it melts. But in the words of Dr. Sheldon Cooper, “irreversible” is an absolute, and using it in this way is sloppy and alarmist.