PBS News Hour: “Hurricane Harvey swamped Houston with seven days of pounding rain last August. When scientists went back to look at historical weather patterns, they reported Harvey dumped 20 percent more rain than it typically would have. The culprit: climate change. Today, we know that Harvey wasn’t an outlier. A new study, published Wednesday in Nature by the same lab, reports that climate change intensified the rains of Hurricane Katrina, Hurricane Irma and Hurricane Maria by between 4 and 9 percent. The researchers predict that future warming could increase rainfall totals for the most extreme hurricanes and tropical cyclones by up to 30 percent.

Humans can also affect these torrential rains through how we engineer cities. A second analysis, also published today in Nature, found the urbanization of the Houston area — namely its skyscrapers and the pervasive use of pavement and other concrete surfaces — made Harvey’s rain dump and subsequent flooding worse. Here’s how both teams used supercomputers to analyze these superstorms and what their research means for future storms…”