Throwing in the towel: In this graphic of the Sacramento Delta region, light blue indicates low-lying land masses–mostly farmland–that research suggests should be surrendered to the sea the next time the levees protecting them break. Yellow indicates borderline cases.
The study even looked in detail at the effects of various topographical changes on fish and the resulting economic costs. “Fish biology is a very complex business, but we sat down with 37 fish biologists, bought them a nice lunch and quizzed them and got a proper statistical distribution of their beliefs of certain species’ surviving under certain scenarios, and came up with economic decision models,” Howitt says. “We are not the only ones doing this, but we are probably one of the more comprehensive. What we’ve done is quantitatively link the different disciplines.”
The analysis would seem to have sobering implications. In terms of sea-level rise, expensive infrastructure investments will have to be made–or willfully not made–in parts of New Orleans, the Everglades, Bangladesh, and the Netherlands, to name just a few obvious spots.
On a more subtle level, climate change will profoundly affect water supplies everywhere, because it will bring deeper droughts, changes in rainfall timing and intensity, and reduced mountain snowpack. “The critical issue is that it will change our planning paradigms, and it will change the information we use to make decisions,” says Richard Palmer, a civil engineer and water-resources expert at the University of Massachusetts, Amherst, who praised the California study. Planning appropriately to keep tap water flowing, Palmer says, will require more such studies that cross disciplines, drawing on climate and atmospheric science, hydrology, civil engineering, and economics.