I may start collecting these stories. I think that water is likely to be the great environmental story of the remainder of my lifetime. This one’s from nature on the challenges that droughts provide for climate science:
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.
Sloan Coats of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York, and his colleagues tested whether a state-of-the-art climate model could simulate the droughts known to have occurred in the southwest during the past millennium. The model incorporated realistic numbers for factors that affect temperature and rainfall, such as atmospheric carbon dioxide levels, changes in solar radiation and ash from volcanic eruptions.
It also incorporated changes in the El Niño/Southern Oscillation (ENSO), a recurring temperature anomaly in the tropical Pacific that greatly affects weather in the western United States and many other parts of the world. (The warm phase — El Niño — often brings torrential rain and flooding; the cold phase — La Niña — tends to bring drought.) The team then compared the results of its simulations with data from the North American Drought Atlas, a detailed compilation of droughts based on the thickness of tree rings.
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.
I think I can tell them why. Is bad water management a major factor in producing droughts? I strongly suspect it is. In the particular case of the El Niño/La Niña oscillation I think that a lot is the consequence of a hot spot on the coast of China.
I love the last paragraph of the linked article. We have no idea of what the weather will be like, and based upon this non-knowledge, we are certain it will be warmer with less water. When your elemental table is limited to four elements, certainty is much easier to attain. Perhaps a few sacrifices to the gods would solve the problem.
The Sahara was once green, and to my knowledge, nobody knows why it became arid. Greenland was once green, but to my knowledge, nobody knows why it became ice covered. Iceland was once ice covered, but to my knowledge, nobody knows why it became green.
When your scientific model does not produce your predicted results, you have a problem. We have been through this before, and we are back to epicycles.