Great floods in China, India and Thailand, super storms in the Philippines and the United States, and summer heat waves in Australia and Japan in recent years, are manifestations of an alarming trend in the rise of climate-related disasters. The 2010s may well go down as the decade when the trend line of these events headed aggressively north after a noticeable rise in their intensity and frequency since the 1970s.

Global warming has contributed to warming oceans, more moisture in the air and higher sea levels, but scientists have been cautious about attributing to climate change a flood or storm. Even so, papers have argued that the intensity of the 2011 Great Flood in Thailand and Super Typhoon Haiyan in the Philippines owed in part to the changing climate. More recent work has been even more pointed: Global warming is shown to have made Japan's unusually hot summer this past year 1.5 to 1.7 times more likely.

A consensus, too, is building that climate change has roots in human actions. We have known for a long time that weather events turn into disasters for man-made reasons. More people are hurt when they are exposed in harm's way, and when they are vulnerable and unable to cope. But now we also know that the intensity and frequency of the hazards themselves are greater because of man-made global warming.