permaculture

[Lawrence London <lfljvenaura@gmail.com>]

BBC News - Rainforest plays critical role in hydropower generation
http://www.bbc.co.uk/news/science-environment-22513233

Deforestation in the Amazon region could significantly reduce the amount of
electricity produced from hydropower, says a new study.

Scientists say the rainforest is critical in generating the streams and
rivers that ultimately turn turbines.

If trees continue to be felled, the energy produced by one of the world's
biggest dams could be cut by a third.

The study <http://www.pnas.org/cgi/doi/10.1073/pnas.1215331110> is
published in the Proceedings of the National Academy of Sciences.

Many countries in tropical regions are turning to hydropower as an untapped
source of energy. In Brazil around 45 new hydro plants are in the planning
stage<http://www.hydroworld.com/articles/2013/02/hydro-energy-projects-still-king-in-brazil.html>.


"We now have very strong evidence that Brazil's ability to generate
electricity depends on forest conservation”
Dr Daniel Nepstad IPAM-IP

Rainforests, by their very name, are prime locations for the dams that are
usually required to create the force of water needed to generate electric
power.

Until now the presumption has been that cutting down the trees near a dam
actually increased the amount of water flowing into the dams.
Trees of life

But in this new study the researchers took a broader look at the climate
projections for the Amazon basin and not just at the rivers on which the
dams were built.

They found that rainforests are more critical than previously thought as
they produce the rain that fills the streams that ultimately drives the
rivers and the turbines.

"Rainforests generate their own rainfall, " Dr Claudia Stickler, from the
Amazon Environmental Research Institute International Programme (IPAM-IP),
told BBC News.
  Brazil has had some success in curbing deforestation but there are
worries that the rate will rise in the coming years

"They pull water out of the soil on a daily basis, they stay green and
dark. The main reason is they are always pumping moisture into the
atmosphere which ultimately ends up being rainfall and that's what keeps
these streams going too," she said.

The scientists found that thanks to current levels of deforestation in the
region, rainfall is 6-7 percent lower than it would be with full forest
cover. Predictions for 2050 suggest a 40% loss of forest, meaning
significantly less rain and 35-40 less electric power.

They researchers looked closely at Brazil's highly
controversial<http://www.economist.com/news/americas/21577073-having-spent-heavily-make-worlds-third-biggest-hydroelectric-project-greener-brazil>Belo
Monte dam, said to be the world's third largest hydropower project. If
deforestation continues the scientists say, the project will deliver 30%
less power than currently estimated. That's equivalent to the energy used
by 4 million Brazilians.

"We now have very strong evidence that Brazil's ability to generate
electricity depends on forest conservation," said co-author Dr Daniel
Nepstad, executive director of IPAM-IP.

"These results aren't just important for Brazil - rainforest cover could
affect energy production in wet tropical areas throughout the Amazon, and
in Africa and South East Asia as well."

The researchers say their work shows that rainforests are not just important
for biodiversity <http://www.bbc.co.uk/news/science-environment-18970076>,
for the storage of carbon but for the very tangible issue of energy
production.

The authors praise the steps that Brazil has taken in recent years to curb
deforestation, but they are concerned that the clearing of trees could now
be on the rise once again.

"In the last year, Brazil has made tremendous progress towards ending
deforestation, bringing clearing rates down to 24% of the historical
average. But these numbers are starting to creep up again, and everyone
should be concerned," said Dr Nepstad.

"Ending deforestation should be viewed as an issue of national energy
security."