This just in from the White House: Global warming is real, and humans are very likely to blame. “Scientific Assesment of the Effects of Global Change on the United States,” one of two reports released today by the Bush administration, acknowledges that rising temperatures and a changing climate could pose challenges for everything from agriculture and water to energy use.

The language, tough by the administration’s standards, largely parrots previous reports by the Intergovernmental Panel on Climate Change, down to the “likely” and “very likely” italics. But the reports are still significant, given the popular perception for years that the administration was at odds with the bulk of scientific research.

The conclusion? “[M]ost of the recent global warming is very likely due to human generated increases in greenhouse gas concentrations.” While there are still questions about the role of sunspots and other natural variations, the report says that “emissions of carbon dioxide from fossil fuel use and from the effects of land use change are the primary sources of this increase.”

As for the impacts, the report paints a fairly grim picture. In the short term, warmer temperatures and higher CO2 concentrations will be good for agriculture—before becoming a bad thing. The health impacts will probably be bad on balance—more malaria, Lyme disease and the like. Ecosystems will suffer. Water supplies will tighten.

But for all the talk about how global warming is affecting the energy mix, the adminsistration’s take on energy is especially interesting: “To date, most discussions on energy and climate change have focused on mitigating human effects on climate. However, along with this role as a driver of climate change, the energy sector will be subject to the effects of climate change.” That is, the U.S. will need more juice the hotter it gets.

And not just for air conditioning, though that’s big part of it. Industrial processes will require more energy, like big refrigeration units. Farms and cities will need more pumped water, requiring more electricity. The upshot? [C]limate change is expected to cause a significant increase in the demand for electricity in the United States, which would require the building of additional electricity production facilities (and probably transmission facilities) at an estimated cost of many billions of dollars.

(Por Keith Johnson, WSJ, 29/05/2008)