November was Chennai’s rainiest calendar month in history: An unimaginable 47 inches fell. Then, this week, things got worse. Wednesday’s rains brought an additional 11 inches—34 times the normal amount. More rain is expected in the coming days, linked to an enhanced northeast monsoon boosted by a record-strong El Niño in the Pacific Ocean and the record-warm Indian Ocean. Flooding is nothing new in Chennai—major floods have occurred there in 1903, 1943, 1978, 1985, 2002, and 2005—but it’s very likely that enhanced evaporation linked to climate change has contributed to this week’s tragedy, making heavy rains more likely. The country’s lead meteorologist as well as its prime minister, Narendra Modi, have both endorsed this linkage.