InsideClimate: When world leaders meet in Paris this December to agree on a new international treaty on climate change, their goal will be to keep atmospheric warming to 2 degrees Celsius, the point after which catastrophic climate change will be nearly inevitable, scientists say. But a new study being published this week by a team of 17 leading international climate scientists warns that even 2 degrees of warming is "highly dangerous" and could cause sea level rise of "at least several meters" this century, leaving...