Michael D. Lemonick

Blooms of algae in the Arctic Ocean could add a previously unsuspected warming feedback to the mix of factors driving temperatures in the north polar regions up faster than any other place on the planet, according to the authors of a new study in Proceedings of the National Academy of Sciences.

Extreme weather events such as droughts, heat waves, and torrential rainfalls are the most powerful and obvious reminders that the climate is changing. These disasters were happening long before humans started pumping heat-trapping greenhouse gases into the atmosphere, but global warming has tipped the odds in their favor. A devastating heat wave like the one that killed 35,000 people in Europe in 2003, for example, is now more than 10 times more likely than it used to be.