New research into the history of the Andes in South America has led scientists to believe that a tipping point is close to being reached in the next 50 years which could see irreversible damage done to the seat of Bolivia’s government in La Paz.
According to the research, if temperatures rise more than 1.5 to 2 degrees Celsius (3 to 5 degrees Fahrenheit) above current levels, parts of Peru and Bolivia situated around Lake Titicaca could very well be turned into dry desert.
The two million inhabitants of La Paz – not to mention the other cities around the lake – would be seriously hard hit, with their water supply and agricultural capacity devastated.
The research is to be published in the November edition of the journal Global Change Biology, and was led by climatologist Mark Bush of the Florida Institute of Technology, who led the team in investigating a 370,000 year record of climate and vegetation in the Andes ecosystems.
Lush One Day, Desert the Next
What they found, by studying fossilized pollen trapped in the sediments of Lake Titicaca which sits across the border of Bolivia and Peru, was that during two of the last three interglacial periods Lake Titicaca decreased in volume by as much as 85 percent. Grass and woodlands in the immediate vicinity were turned to dust and in each case a steady warming took place that caused trees to migrate upslope.
Just as is happening in the region today.
“The evidence is clear that there was a sudden change to a much drier state,” said lead scientist Bush.
Increased temperatures resulted in a severe diminishment of the lake, which had an adverse effect on the population of the lake itself, as well as those living around it. As a lake as large as Titicaca shrinks, so too does the rainfall in the surrounding area, along with many other local climate effects.
While tipping points have been postulated and seen in other studies, the research done by the scientists studying the Andes ecosystem created the opportunity to define when the system will change.
Based on the growth limits of the Andean forests, the scientists defined a tipping point that took place whenever the temperature exceeded 1.5 to 2 degrees Celsius above current levels.
Source: National Science Foundation
Image Source: NASA