Après CO2, le déluge

Downtown Sacramento, 1862 (Chron photo)

Five years ago we wrote about how a wet winter (yes, they do exist) gave rise to fears of disastrous floods in Northern California.

There is historical precedent: in the Great Flood of 1862 Sacramento and much of the Central Valley was submerged. No one's predicted when such a flood will recur but we remarked half jokingly,

"One Thing is Certain: Climate Change Will Take the Blame"

It's no longer a joke. Scientists are warning that climate change will make Great Floods more likely and more severe. [bold added]

Storms seem hard to fathom now, with California in its third year of drought. But climate change is making both drought and rainstorms more prolonged and intense, climatologists believe.

The dense 13-page treatise [“Climate change is increasing the risk of a California megaflood”] uses the Great Flood of 1862 as its model. An overwhelming series of storms turned the entire Central Valley into an inland sea and washed out what is now Los Angeles and the cities of Orange County. That flood caused an estimated 4,000 deaths as the equivalent of 10 feet of rain fell over a span of 43 days, according to references.

The study says that climate change is dramatically increasing the risk of megastorms like the one that spawned the 1862 flood, so that an event that would have occurred only once every two centuries is becoming one that might occur around three times each century. Just as worrisome, the consequences could be worse now due to the combined conditions of human-induced global warming, sprawling development and wildfires.

Recent analysis has suggested that “such an event would likely produce widespread, catastrophic flooding and subsequently lead to the displacement of millions of people, the long-term closure of critical transportation corridors and ultimately to nearly $1 trillion in overall economic losses,” the study states.

Global warming, aka "climate change," is responsible for mega-droughts and mega-floods.

It causes ocean warming and ocean cooling.

There's nothing it can't do.