---------- Forwarded message ----------
From: RWESA <rwesa@rwesa.org>
Date: 2007/05/10 22:47
Subject: [RWESA-Friends] 4% of Global Warming Due to Dams, Says New Research
To: rwesa@lists.irn.org
Methane From Dams: Greenhouse Gas to Power Source
http://www.ens-newswire.com/ens/may2007/2007-05-09-04.asp
SAO JOSE DOS CAMPOS, Brazil, May 9, 2007 (ENS) - Scientists from Brazil's
National Institute for Space Research, INPE, have published a new study showing
that large dams contribute to global warming by releasing the greenhouse gas
methane into the atmosphere. The authors propose capturing the methane and
using it to generate electricity.
Dr. Ivan Lima and his colleagues used a theoretical model, bootstrap resampling
and data provided by the International Commission On Large Dams World register
of dams to demonstrate that global large dams annually release about 104
million metric tons of methane to the atmosphere through reservoir surfaces,
turbines and spillways.
Methane is the principal component of natural gas. The INPE scientists say
engineering technologies now in existence can be implemented to avoid these
emissions, and to recover the non-emitted methane for power generation.
Under the Clean Development Mechanism of the Kyoto Protocol, they write, such
technologies can be recognized as promising alternatives for human adaptations
to climate change, particularly in developing nations owning a considerable
number of large dams.
Methane is about 21 times more powerful at warming the atmosphere than the most
abundant greenhouse gas, carbon dioxide. Methane's relatively short atmospheric
lifetime of 12 years, coupled with its potency as a greenhouse gas, makes
methane a candidate for mitigating global warming in the short term.
Dr. Lima and his co-authors propose capturing methane in reservoirs and using
it to fuel power plants in Brazil, China and India.
"If we can generate electricity from the huge amounts of methane produced by
existing tropical dams we can avoid the need to build new dams with their
associated human and environmental costs," Lima said.
The immediate benefits of recovering methane from large dams for renewable
energy production is the mitigation of human impacts like the construction of
new large dams, avoidance of the actual methane emissions from large dams, and
the use of unsustainable fossil fuels and natural gas reserves, the authors
explain in their study, published by Springer Netherlands.
Large hydroelectric dams release methane into the atmosphere because trees and
other plants settle to the bottom when the reservoir is first flooded. This
plant material decomposes without oxygen and dissolved methane builds up. When
water passes through the dam's turbines, this methane is released.
Executive Director of International Rivers Network Patrick McCully said today,
"Climate policy makers must address this issue."
From his office in Berkeley, California, McCully said Lima's calculations imply
that the world's 52,000 large dams contribute more than four percent of the
total warming impact of human activities.
They also imply that dam reservoirs are the largest single source of
human-caused methane emissions, contributing around a quarter of these
emissions, McCully said.
The massive amounts of methane produced by hydropower reservoirs in the tropics
mean that these dams can have a much higher warming impact than even the
dirtiest fossil fuel plants generating similar quantities of electricity, he
said.
"It is unfortunate that Lima's study has come too late to be included in the
recent reports from the Intergovernmental Panel on Climate Change, IPCC,"
McCully said. "Partly because of the influence of the hydro industry and its
government backers, climate policymakers have largely overlooked the importance
of dam-generated methane."
Another Brazilian scientist has also made the connection. Philip Fearnside from
Brazil's National Institute for Research in the Amazon in Manaus published a
study in 2002 showing that the greenhouse effect of emissions from the
Curua-Una dam in Para, Brazil in 1990, was more than 3.5 times what would have
been produced by generating the same amount of electricity from oil.
The International Hydropower Association, IHA, says considering only total
greenhouse gases measured at the surface of reservoirs can be misleading; these
measurements should be considered as "gross" emissions. "Net" emissions for
which dams are responsible must consider the emissions from ecosystems before
the creation of a reservoir when the land was in its natural state.
International Rivers Network
Press Release
May 9, 2007
Contacts:
? Patrick McCully, Executive Director, IRN, Berkeley, California:
+1 510 213 1441 (mobile) +1 510 848 1155 (office), patrick@irn.org
? Ivan Lima, National Institute for Space Research, Brazil:
+ 55 67 3233-2430 ext. 241 (office) ivan@dsr.inpe.br
? Tim Kingston, Communications Manager, IRN, Berkeley, California:
+1 510 290 7170 (mobile) +1 510 848 1155 (office), tim@irn.org
Four Percent of Global Warming Due to Dams, Says New Research
Large dams may be one of the single most important contributors to
global warming, releasing 104 million metric tonnes of methane each
year. This estimate was recently published in a peer-reviewed journal
by Ivan Lima and colleagues from Brazil's National Institute for Space
Research (INPE).
"There is now more than enough evidence to show that large dams are a
major source of climate-changing pollution," says Patrick McCully,
Executive Director of International Rivers Network. "Climate policy
makers must address this issue."
Lima's calculations imply that the world's 52,000 large dams contribute
more than 4% of the total warming impact of human activities. They also
imply that dam reservoirs are the largest single source of human-caused
methane emissions, contributing around a quarter of these emissions.
Methane is a more potent heat-trapping gas than carbon dioxide,
although it does not last as long in the atmosphere. One year's large
dam methane emissions, as estimated by Lima, have a global warming
impact over 20 years equivalent to that of 7.5 billion tonnes of carbon
dioxide ? higher than annual carbon dioxide emissions from fossil fuel
burning in the US.
Lima and his co-authors propose capturing methane in reservoirs and
using it to fuel power plants. Lima says, "If we can generate
electricity from the huge amounts of methane produced by existing
tropical dams we can avoid the need to build new dams with their
associated human and environmental costs."
"It is unfortunate that Lima's study has come too late to be included
in the recent reports from the Intergovernmental Panel on Climate
Change," says Patrick McCully. "Partly because of the influence of the
hydro industry and its government backers, climate policy-makers have
largely overlooked the importance of dam-generated methane. The IPCC
urgently needs to address this issue."
Methane is produced by the rotting of organic material in reservoirs.
The massive amounts of methane produced by hydropower reservoirs in the
tropics mean that these dams can have a much higher warming impact than
even the dirtiest fossil fuel plants generating similar quantities of
electricity.
This is only the second estimate published in the scientific literature
of global greenhouse gas emissions from dams. The previous estimate,
published in 2000, which included only emissions from reservoir
surfaces, estimated global releases at 70 million tonnes of methane and
a billion tonnes of carbon dioxide.
Lima's calculations take account of emissions from turbines and
spillways and the rivers immediately downstream of dams, in addition to
reservoir surfaces. Lima's paper does not address dam emissions of
carbon dioxide or another greenhouse gas, nitrous oxide.
Lima has also produced the first published estimates of methane
emissions from dams at the national level in Brazil, China and India.
These estimates show dams in Brazil and India are responsible for a
fifth of these countries' total global warming impact. Dams in China
are estimated to produce 1% of the country's climate pollution,
although for methodological reasons this is likely an underestimate.
--30--
More information:
? Ivan B.T. Lima et al. (2007) "Methane Emissions from Large Dams
as Renewable Energy Resources: A Developing Nation Perspective,"
Mitigation and Adaptation Strategies for Global Change, published
on-line March 2007. http://tinyurl.com/2bzawj
? "FAQ: Greenhouse Gas Emissions from Dams."
http://www.irn.org/pdf/greenhouse/GlobalResGHGsFAQ.pdf
? IRN web pages on reservoir emissions.
http://www.irn.org/programs/greenhouse/index.php?id=resemissions.html
From: RWESA <rwesa@rwesa.org>
Date: 2007/05/10 22:47
Subject: [RWESA-Friends] 4% of Global Warming Due to Dams, Says New Research
To: rwesa@lists.irn.org
Methane From Dams: Greenhouse Gas to Power Source
http://www.ens-newswire.com/ens/may2007/2007-05-09-04.asp
SAO JOSE DOS CAMPOS, Brazil, May 9, 2007 (ENS) - Scientists from Brazil's
National Institute for Space Research, INPE, have published a new study showing
that large dams contribute to global warming by releasing the greenhouse gas
methane into the atmosphere. The authors propose capturing the methane and
using it to generate electricity.
Dr. Ivan Lima and his colleagues used a theoretical model, bootstrap resampling
and data provided by the International Commission On Large Dams World register
of dams to demonstrate that global large dams annually release about 104
million metric tons of methane to the atmosphere through reservoir surfaces,
turbines and spillways.
Methane is the principal component of natural gas. The INPE scientists say
engineering technologies now in existence can be implemented to avoid these
emissions, and to recover the non-emitted methane for power generation.
Under the Clean Development Mechanism of the Kyoto Protocol, they write, such
technologies can be recognized as promising alternatives for human adaptations
to climate change, particularly in developing nations owning a considerable
number of large dams.
Methane is about 21 times more powerful at warming the atmosphere than the most
abundant greenhouse gas, carbon dioxide. Methane's relatively short atmospheric
lifetime of 12 years, coupled with its potency as a greenhouse gas, makes
methane a candidate for mitigating global warming in the short term.
Dr. Lima and his co-authors propose capturing methane in reservoirs and using
it to fuel power plants in Brazil, China and India.
"If we can generate electricity from the huge amounts of methane produced by
existing tropical dams we can avoid the need to build new dams with their
associated human and environmental costs," Lima said.
The immediate benefits of recovering methane from large dams for renewable
energy production is the mitigation of human impacts like the construction of
new large dams, avoidance of the actual methane emissions from large dams, and
the use of unsustainable fossil fuels and natural gas reserves, the authors
explain in their study, published by Springer Netherlands.
Large hydroelectric dams release methane into the atmosphere because trees and
other plants settle to the bottom when the reservoir is first flooded. This
plant material decomposes without oxygen and dissolved methane builds up. When
water passes through the dam's turbines, this methane is released.
Executive Director of International Rivers Network Patrick McCully said today,
"Climate policy makers must address this issue."
From his office in Berkeley, California, McCully said Lima's calculations imply
that the world's 52,000 large dams contribute more than four percent of the
total warming impact of human activities.
They also imply that dam reservoirs are the largest single source of
human-caused methane emissions, contributing around a quarter of these
emissions, McCully said.
The massive amounts of methane produced by hydropower reservoirs in the tropics
mean that these dams can have a much higher warming impact than even the
dirtiest fossil fuel plants generating similar quantities of electricity, he
said.
"It is unfortunate that Lima's study has come too late to be included in the
recent reports from the Intergovernmental Panel on Climate Change, IPCC,"
McCully said. "Partly because of the influence of the hydro industry and its
government backers, climate policymakers have largely overlooked the importance
of dam-generated methane."
Another Brazilian scientist has also made the connection. Philip Fearnside from
Brazil's National Institute for Research in the Amazon in Manaus published a
study in 2002 showing that the greenhouse effect of emissions from the
Curua-Una dam in Para, Brazil in 1990, was more than 3.5 times what would have
been produced by generating the same amount of electricity from oil.
The International Hydropower Association, IHA, says considering only total
greenhouse gases measured at the surface of reservoirs can be misleading; these
measurements should be considered as "gross" emissions. "Net" emissions for
which dams are responsible must consider the emissions from ecosystems before
the creation of a reservoir when the land was in its natural state.
International Rivers Network
Press Release
May 9, 2007
Contacts:
? Patrick McCully, Executive Director, IRN, Berkeley, California:
+1 510 213 1441 (mobile) +1 510 848 1155 (office), patrick@irn.org
? Ivan Lima, National Institute for Space Research, Brazil:
+ 55 67 3233-2430 ext. 241 (office) ivan@dsr.inpe.br
? Tim Kingston, Communications Manager, IRN, Berkeley, California:
+1 510 290 7170 (mobile) +1 510 848 1155 (office), tim@irn.org
Four Percent of Global Warming Due to Dams, Says New Research
Large dams may be one of the single most important contributors to
global warming, releasing 104 million metric tonnes of methane each
year. This estimate was recently published in a peer-reviewed journal
by Ivan Lima and colleagues from Brazil's National Institute for Space
Research (INPE).
"There is now more than enough evidence to show that large dams are a
major source of climate-changing pollution," says Patrick McCully,
Executive Director of International Rivers Network. "Climate policy
makers must address this issue."
Lima's calculations imply that the world's 52,000 large dams contribute
more than 4% of the total warming impact of human activities. They also
imply that dam reservoirs are the largest single source of human-caused
methane emissions, contributing around a quarter of these emissions.
Methane is a more potent heat-trapping gas than carbon dioxide,
although it does not last as long in the atmosphere. One year's large
dam methane emissions, as estimated by Lima, have a global warming
impact over 20 years equivalent to that of 7.5 billion tonnes of carbon
dioxide ? higher than annual carbon dioxide emissions from fossil fuel
burning in the US.
Lima and his co-authors propose capturing methane in reservoirs and
using it to fuel power plants. Lima says, "If we can generate
electricity from the huge amounts of methane produced by existing
tropical dams we can avoid the need to build new dams with their
associated human and environmental costs."
"It is unfortunate that Lima's study has come too late to be included
in the recent reports from the Intergovernmental Panel on Climate
Change," says Patrick McCully. "Partly because of the influence of the
hydro industry and its government backers, climate policy-makers have
largely overlooked the importance of dam-generated methane. The IPCC
urgently needs to address this issue."
Methane is produced by the rotting of organic material in reservoirs.
The massive amounts of methane produced by hydropower reservoirs in the
tropics mean that these dams can have a much higher warming impact than
even the dirtiest fossil fuel plants generating similar quantities of
electricity.
This is only the second estimate published in the scientific literature
of global greenhouse gas emissions from dams. The previous estimate,
published in 2000, which included only emissions from reservoir
surfaces, estimated global releases at 70 million tonnes of methane and
a billion tonnes of carbon dioxide.
Lima's calculations take account of emissions from turbines and
spillways and the rivers immediately downstream of dams, in addition to
reservoir surfaces. Lima's paper does not address dam emissions of
carbon dioxide or another greenhouse gas, nitrous oxide.
Lima has also produced the first published estimates of methane
emissions from dams at the national level in Brazil, China and India.
These estimates show dams in Brazil and India are responsible for a
fifth of these countries' total global warming impact. Dams in China
are estimated to produce 1% of the country's climate pollution,
although for methodological reasons this is likely an underestimate.
--30--
More information:
? Ivan B.T. Lima et al. (2007) "Methane Emissions from Large Dams
as Renewable Energy Resources: A Developing Nation Perspective,"
Mitigation and Adaptation Strategies for Global Change, published
on-line March 2007. http://tinyurl.com/2bzawj
? "FAQ: Greenhouse Gas Emissions from Dams."
http://www.irn.org/pdf/greenhouse/GlobalResGHGsFAQ.pdf
? IRN web pages on reservoir emissions.
http://www.irn.org/programs/greenhouse/index.php?id=resemissions.html
