How much does Hurricane Harvey, or any particular storm, have to do with climate change?

The relationship between hurricanes and climate change is not simple. Some things are known with growing certainty. Others, not so much.

The most recent draft of a sweeping climate science report pulled together by 13 federal agencies as part of the National Climate Assessment suggested that the science linking hurricanes to climate change was still emerging. Looking back through the history of storms, “the trend signal has not yet had time to rise above the background variability of natural processes,” the report states.

Temperatures have been rising, and theory and computer modeling suggest an increase in storm intensity in a warmer world, “and the models generally show an increase in the number of very intense” storms.