So Louisiana is sinking below the waves, is it?
With higher temperatures, eggs are hatching faster. Despite a harvesting programme, there are now two million wild alligators in the state, up from 100,000 half a century ago.
It’s yet another sign of the devastating impact of climate change in Louisiana.
Hundreds of thousands of people have become climate refugees in their own state, moving to higher ground, away from low-lying areas that have either been repeatedly deluged during tropical storms and deadly hurricanes, or lost to the ocean completely.
To the east, in the Mississippi Delta, sea levels are rising. Since 1932, some 1,883 square miles of land have been submerged. If this was Delaware or Rhode Island, America would have one fewer state.
Sigh. This has been gone over before.
Yes, Louisiana doesn’t have as much land as it used to, as it might have done without human intervention. But it is necessary to get right which human intervention has done for it. And it ain’t climate.
The clue is in that “delta” bit. The Mississippi drains pretty much all of the US from the Canadian border – almost, there’s a bit that goes north into the Great Lakes -, east of the Rockies and west of the Appalachians. It’s as if there’s just the one river for an entire third of Europe.
And that much water rolling by carries with it a certain amount of soil. Every year. Which is what that delta is, the last few thousand years of build up of the top inch of Iowa, Missouri, Ohio and so on, that has floated down river.
Such deltas carry on growing as long as the silt keeps arriving. Which, if you straighten out the river, dam it, put levees up, it still does. But faster, meaning that the silt gets dumped out in the gulf, not on the delta. Then you also stop the flooding, allow the delta to dry out.
What happens? You start losing that land to the sea. You also stop the land building up as it would do from that silt.
Sure, Louisiana is now smaller than it would have been without human intervention. But it’s the Army Corps of Engineers, not climate change.