Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Catastrophic Drought Looms for Capital City of Bolivia

15.11.2010
Historical ecology of the Andes indicates desert-like setting on the horizon

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.

Scientist Sherilyn Fritz at the University of Nebraska-Lincoln showed that during these warm episodes the algae living in Lake Titicaca shifted from freshwater species to ones tolerant of salty water. Paul Baker of Duke University identified peaks of carbonate deposition.

Both point to a sudden shallowing of the lake due to evaporative loss.

An environmental reconstruction demonstrates that with moderate warming, forests moved upslope. But as that warming continued, a climate tipping point was reached.

The system was thrown into a new, drier state that halted forest expansion.

The tipping point is caused by increased evaporative loss from Lake Titicaca.

As the lake contracts, the local climate effects attributable to a large lake--doubling of rainfall, among the most important--would be lost, says Bush.

Such tipping points have been postulated by other studies, but this work allowed the researchers to state when the system will change.

Based on the growth limits of Andean forests, they defined a tipping point that was exceeded within a 1.5 to 2 degrees Celsius warming above modern conditions.

Given a rate of warming in the Peruvian Andes of about 0.3-0.5 degrees Celsius per decade, the tipping point ahead would be reached between 2040 and 2050.

"The implications would be profound for some two million people," says Paul Filmer, program director in NSF's Division of Earth Sciences. Severe drought, and a loss of stored water in lakes in the region, would reduce yields from important agricultural regions and threaten drinking water supplies.

The research suggests that limiting wildfires would help delay the worst effects of the drought.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov
http://nsf.gov/news/news_summ.jsp?cntn_id=118047&org=NSF&from=news

More articles from Ecology, The Environment and Conservation:

nachricht How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.

nachricht Using drones to estimate crop damage by wild boars
12.12.2017 | Gesellschaft für Ökologie e.V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>