Story submitted by WUWT reader “Clyde”
Simulations identify past megadroughts, but at wrong times.
“This would be a fine country if it only had water,” observes a settler looking at the barren west Texas plains. “So would Hell,” replies a despairing farmer.
That old Texas joke probably originated in the 1950s, when the state was baked by its most relentless drought in recorded history.
Reliable forecasts of future ‘megadroughts’ would be a boon to farmers and water managers. But results presented last week at the annual assembly of the European Geosciences Union in Vienna suggest that such forecasts are still beyond the reach of current climate models.
The results were puzzling. Although the simulation produced a number of pronounced droughts lasting several decades each, these did not match the timing of known megadroughts. In fact, drought occurrences were no more in agreement when the model was fed realistic values for variables that influence rainfall than when it ran control simulations in which the values were unrealistically held constant.
“The model seems to miss some of the dynamics that drive large droughts,” says study participant Jason Smerdon, a researcher at Lamont-Doherty who studies historical climate patterns.