National Science Foundation: Catastrophic drought is on the near-term horizon for the capital city of Bolivia, according to new research into the historical ecology of the Andes. If temperatures rise more than 1.5 to 2 degrees Celsius (3 to 5 degrees Fahrenheit) above those of modern times, parts of Peru and Bolivia will become a desert-like setting.The change would be disastrous for the water supply and agricultural capacity of the two million inhabitants of La Paz, Bolivia's capital city, scientists say. The results, derived from research funded by the National Science Foundation (NSF) and conducted by scientists affiliated with the Florida Institute of Technology (FIT), appear in the November issue of the journal Global Change Biology.
Climatologist Mark Bush of FIT led a research team investigating a 370,000-year record of climate and vegetation change in Andean ecosystems. The scientists used fossilized pollen trapped in the sediments of Lake Titicaca, which sits on the border of Peru and Bolivia.
They found that during two of the last three interglacial periods, which occurred between 130,000-115,0000 years ago and 330,000-320,000 years ago, Lake Titicaca shrank by as much as 85 percent. Adjacent shrubby grasslands were replaced by desert.
In each case, a steady warming occurred that caused trees to migrate upslope, just as they are doing today. However, as the climate kept warming, the system suddenly flipped from woodland to desert. "The evidence is clear that there was a sudden change to a much drier state," said Bush….
One view of La Paz, shot by marcalandavis, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license.
No comments:
Post a Comment