Marina Koren writes:

Water gave every living thing on Earth the gift of existence. And yet, of late, it seems determined to wipe us out. The Atlantic hurricane season, widely predicted to be a fierce one, is here, and early this morning the first named storm, Alberto, made landfall in northeastern Mexico and drenched everything in its path.

And in Florida last week, it was as if the heavens had turned on the tap and simply left it running. The state’s south usually gets about eight to 10 inches of rain throughout June; some parts of Southern Florida received about 20 inches of rain in just 24 hours, turning streets impassable, damaging homes, and enveloping cars.

This type of rainfall has become more frequent and intense in recent decades. A warmer atmosphere can hold more moisture, and plenty is available as warmer temperatures at the Earth’s surface allow more water to evaporate. In a hotter world, when it rains, it really pours. Experts call torrents such as those in Florida 100-year storms, even 1,000-year storms. And yet, they’ve been occurring with alarming frequency across the United States and in other parts of the world.

Extreme precipitation is a sign of how fundamentally humans have managed to alter the workings of our planet. The first rains on Earth fell several billion years ago, covering the once-molten surface with seas where life eventually emerged. Even now, as scientists search for signs of habitable worlds beyond Earth, they follow the water because they understand that it turned this little ball of rock into a paradise for life. But by burning fossil fuels for about 250 years—no time at all, on the scale of our planet’s history—humans have turned a cosmic wonder into a weapon. [Continue reading…]