Berger provides useful context from Andrew Dessler, a climate scientist at Texas A&M University, who noted that most people publishing on this question have long seen very low odds of runaway or extreme warming:
My sense is that most scientists consider the very high end of the sensitivity range… to be pretty unlikely (although it cannot be ruled out)…. In other words, I was not terribly worried about runaway climate change before this. After all, we know that the Earth’s had much higher CO2 in the past (and the temperature were correspondingly much higher), and the Earth did not turn into Venus.
NOAA’s Arctic report card released at #AGU17
3 hours ago