Andrew Yee[_1_]
February 2nd 07, 01:12 PM
ESA News
http://www.esa.int
1 February 2007
Satellite data vital to UN climate findings
The most authoritative report on climate change to date will be released
tomorrow in Paris, France, and is expected to warn of rising global sea
levels and temperatures. Earth observation from space plays an invaluable
role in helping scientists advance our understanding of climate change and
capability to model its evolution.
The Intergovernmental Panel on Climate Change (IPCC) developed the report,
'Climate Change 2007', over six years with a panel of 2 500 scientific
expert reviewers from 130 countries. Predictions for the future of global
warming in the report, intended as a summary for policymakers, are based on
19 computer models.
Many scientists and policy makers agree climate change is the biggest
problem facing the planet today. A better understanding of global-warming
phenomena requires sophisticated models of the Earth System including the
atmosphere, ocean, biosphere and cryosphere.
The ability of satellites to deliver global data on the Earth System makes
them particularly useful to study climate change and to validate and assess
the quality of climate models. In addition, long-term and consistent Earth
observation (EO) data sets enable scientists to identify significant trends
and patterns in the climate. ESA's Envisat, the world's largest
environmental satellite, affords this to scientists by providing continuity
of data initiated in the early 1990s with previous ESA satellites ERS-1,
ESA's first observation satellite launched in 1991, and ERS-2.
A space-borne instrument known as a radar altimeter offers valuable
information on the state of the ocean by providing measurements of the
height of the ocean surface. Data acquired by radar altimeters aboard
Envisat and ERS show sea levels have been rising by three mm a year since
the early 1990s.
Other evidence of global warming can be found in the melting of polar
sea-ice and ice caps. Satellites are often the only means of studying the
Earth's Polar Regions because of their remoteness, darkness and cloudiness.
An instrument known as the Advanced Synthetic Aperture Radar (ASAR) allows
Envisat to produce high-quality images of ice sheets in Greenland and
Antarctica because it is able to pierce through clouds and darkness.
Using satellite data collected by ESA's ERS-1, ERS-2 and Envisat and
Canada's Radarsat-1, Eric Rignot of NASA's Jet Propulsion Laboratory (JPL)
in California and University of Kansas scientist Pannir Kanagaratnam made a
discovery in 2006 that the Greenland Glaciers are melting at a pace twice as
fast as previously thought. Such a rapid pace of melting was not considered
in previous simulations of climate change, therefore showing the important
role of Earth observation in advancing our knowledge of climate change and
improving climate models.
"Satellites have produced major advances in our understanding of the
evolution of ice sheets in a warmer climate. In particular they documented
large changes taking place in polar regions, e.g. Greenland and Antarctica,
which result from climate warming, over the most inaccessible regions of the
world," Rignot said.
Satellites are useful for helping build scenarios of greenhouse gas
emissions, such as methane -- the second most important greenhouse gas after
carbon dioxide. Using the Scanning Imaging Absorption Spectrometer for
Atmospheric Chartography (SCIAMACHY) instrument aboard Envisat, researchers
at the University of Heidelberg in 2005 were able to confirm increased
methane concentrations induced mainly by human activities.
Satellites also help scientists to better understand the carbon cycle by
providing measurements of some of the variables required as inputs to
carbon-cycle models, such as daily global albedo (the fraction of sunlight
reflected back from the Earth), fires and mapping of land-use change and
forestry activities.
Climate change also poses a great threat to the world economy. 'The
Economics of Climate Change' report, also called the Stern review, compiled
by Sir Nicholas Stern for the UK government and released on 30 October 2006,
estimates that if we do nothing about climate change, the overall costs and
risks will be equivalent to losing at least 5% of global gross domestic
product (GDP) each year. In contrast, Stern says, the costs of reducing
greenhouse gas emissions can be limited to around 1% of global GDP each
year.
ESA's Living Planet Programme, through the development of satellite missions
like the Earth Explorer series and new missions such as the Sentinel
missions that support Global Monitoring for Environment and Security (GMES),
will continue to advance our understanding of the Earth System, predict
environmental changes and help mitigate the negative effects of global
change on the population.
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEMRJTSMTWE_index_1.html ]
http://www.esa.int
1 February 2007
Satellite data vital to UN climate findings
The most authoritative report on climate change to date will be released
tomorrow in Paris, France, and is expected to warn of rising global sea
levels and temperatures. Earth observation from space plays an invaluable
role in helping scientists advance our understanding of climate change and
capability to model its evolution.
The Intergovernmental Panel on Climate Change (IPCC) developed the report,
'Climate Change 2007', over six years with a panel of 2 500 scientific
expert reviewers from 130 countries. Predictions for the future of global
warming in the report, intended as a summary for policymakers, are based on
19 computer models.
Many scientists and policy makers agree climate change is the biggest
problem facing the planet today. A better understanding of global-warming
phenomena requires sophisticated models of the Earth System including the
atmosphere, ocean, biosphere and cryosphere.
The ability of satellites to deliver global data on the Earth System makes
them particularly useful to study climate change and to validate and assess
the quality of climate models. In addition, long-term and consistent Earth
observation (EO) data sets enable scientists to identify significant trends
and patterns in the climate. ESA's Envisat, the world's largest
environmental satellite, affords this to scientists by providing continuity
of data initiated in the early 1990s with previous ESA satellites ERS-1,
ESA's first observation satellite launched in 1991, and ERS-2.
A space-borne instrument known as a radar altimeter offers valuable
information on the state of the ocean by providing measurements of the
height of the ocean surface. Data acquired by radar altimeters aboard
Envisat and ERS show sea levels have been rising by three mm a year since
the early 1990s.
Other evidence of global warming can be found in the melting of polar
sea-ice and ice caps. Satellites are often the only means of studying the
Earth's Polar Regions because of their remoteness, darkness and cloudiness.
An instrument known as the Advanced Synthetic Aperture Radar (ASAR) allows
Envisat to produce high-quality images of ice sheets in Greenland and
Antarctica because it is able to pierce through clouds and darkness.
Using satellite data collected by ESA's ERS-1, ERS-2 and Envisat and
Canada's Radarsat-1, Eric Rignot of NASA's Jet Propulsion Laboratory (JPL)
in California and University of Kansas scientist Pannir Kanagaratnam made a
discovery in 2006 that the Greenland Glaciers are melting at a pace twice as
fast as previously thought. Such a rapid pace of melting was not considered
in previous simulations of climate change, therefore showing the important
role of Earth observation in advancing our knowledge of climate change and
improving climate models.
"Satellites have produced major advances in our understanding of the
evolution of ice sheets in a warmer climate. In particular they documented
large changes taking place in polar regions, e.g. Greenland and Antarctica,
which result from climate warming, over the most inaccessible regions of the
world," Rignot said.
Satellites are useful for helping build scenarios of greenhouse gas
emissions, such as methane -- the second most important greenhouse gas after
carbon dioxide. Using the Scanning Imaging Absorption Spectrometer for
Atmospheric Chartography (SCIAMACHY) instrument aboard Envisat, researchers
at the University of Heidelberg in 2005 were able to confirm increased
methane concentrations induced mainly by human activities.
Satellites also help scientists to better understand the carbon cycle by
providing measurements of some of the variables required as inputs to
carbon-cycle models, such as daily global albedo (the fraction of sunlight
reflected back from the Earth), fires and mapping of land-use change and
forestry activities.
Climate change also poses a great threat to the world economy. 'The
Economics of Climate Change' report, also called the Stern review, compiled
by Sir Nicholas Stern for the UK government and released on 30 October 2006,
estimates that if we do nothing about climate change, the overall costs and
risks will be equivalent to losing at least 5% of global gross domestic
product (GDP) each year. In contrast, Stern says, the costs of reducing
greenhouse gas emissions can be limited to around 1% of global GDP each
year.
ESA's Living Planet Programme, through the development of satellite missions
like the Earth Explorer series and new missions such as the Sentinel
missions that support Global Monitoring for Environment and Security (GMES),
will continue to advance our understanding of the Earth System, predict
environmental changes and help mitigate the negative effects of global
change on the population.
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEMRJTSMTWE_index_1.html ]