India, Aug. 24 -- I think often about a stretch of Mumbai's coast I used to walk as a child, where mangroves stood thick enough to hide egrets. A restaurant sits there now, with a view of a horizon that used to belong to birds. A shoreline rarely disappears all at once. Attention leaves first, and by the time we look again, the mangrove has thinned to memory, and what remains is a coastline that has learned to look like the absence of one.

Recent monsoons have recorded rainfall at 600 to 1,700% of normal through sudden cloudbursts, even as the season overall ran at a national deficit. Kerala is living this paradox. Districts that had gone months carrying a rainfall deficit of more than 50% have since been deluged, receiving 232% excess r...