Global brightening

Per the NYT, the amount of sunlight reaching the ground has been
increasing over the past 10 year or so reversing a dimming trend.
(Local dimness in Hong Kong/India remain).

http://www.nytimes.com/2005/05/06/science/06bright.html

May 6, 2005
Earth Has Become Brighter, but No One Is Sure Why
By KENNETH CHANG

Reversing a decades-long trend toward "global dimming," Earth's surface
has become brighter since 1990, scientists are reporting today.

The brightening means that more sunlight - and thus more heat - is
reaching the ground. That could partly explain the record-high global
temperatures reported in the late 1990's, and it could accelerate the
planet's warming trend.

"We see the dimming is no longer there," said Dr. Martin Wild, a
climatologist at the Swiss Federal Institute of Technology in Zurich and
the lead author of one of three papers analyzing sunlight that appear in
today's issue of the journal Science. "If anything, there is a brightening."

Some scientists have reported that from 1960 to 1990, the amount of
sunshine reaching the ground decreased at a rate of 2 percent to 3
percent per decade.

In some places, the brightening of the 1990's has more than offset the
dimming, Dr. Wild said. In other places, like Hong Kong, which lost more
than a third of its sunlight, the dimming has leveled off, but skies
remain darker than in the past. In a few places, like India, the dimming
trend continues, he said.

The new papers also call attention to a major gap in the understanding
of climate. Scientists do not exactly know what caused the dimming and
the brightening, or how they affect the rest of the climate system.

Earth reflects about 30 percent of the incoming sunlight back into
space. Slight changes in the reflectivity, possibly caused by changes in
cloud cover and air pollution, can have as much impact on the climate as
heat-trapping greenhouse gases like carbon dioxide.

Some scientists say that the dimming and the brightening might explain
why for many years temperatures on Earth lagged what was predicted by
many climate models and then shot upward more recently.

"I think what could have happened is the dimming between the 60's and
80's counteracted the greenhouse effect," Dr. Wild said. "When the
dimming faded, the effects of the greenhouse gases became more evident.
There is no masking by the dimming anymore."

But Dr. Rachel T. Pinker, a professor of meteorology at the University
of Maryland who led the team that wrote one of the other papers, said
the picture might not be so simple. More sunlight should increase
evaporation rates, leading to more clouds, and the additional cloud
cover could then increase Earth's reflectivity, limiting the warming effect.

"I think that's a complex issue," Dr. Pinker said. "There are many
feedbacks involved."

The findings of Dr. Wild and his colleagues are based on data through
2001 from a network of ground-based sensors that directly measure the
sunlight hitting the ground. But the sensors are not evenly distributed,
with the greatest number in Europe, few in Africa and South America, and
none covering the 70 percent of Earth's surface that is water.

Dr. Pinker's team analyzed satellite data from 1983 to 2001 that covered
the globe. Its findings about brightening, which basically agree with
Dr. Wild's, rely on computer models to estimate how much sunlight
reaches the surface.

Finally, a team led by Dr. Bruce A. Wielicki of NASA's Langley Research
Center in Virginia reports that measurements from the agency's Aqua
satellite show a slight decrease in the amount of light reflected off
Earth since 2000, which corresponds to a brightening on the surface.

The NASA findings conflict with measurements, reported last year,
suggesting that Earth had resumed dimming since 2000. Those measurements
looked at the illumination of the dark side of the Moon by light
reflected off Earth.

Dr. Philip R. Goode, a professor of physics at the New Jersey Institute
of Technology who was one of the researchers behind last year's report,
said it was not clear why the findings differed so markedly. "We've been
working with them to understand the origins of the differences," Dr.
Goode said of the Wielicki group.

Dr. Wielicki said his data supported a report last month by a team led
by Dr. James E. Hansen of the Goddard Institute for Space Studies in New
York. In a paper published on Science's Web site, Dr. Hansen and his
colleagues said much of the excess heat generated by global warming has
been stored in the oceans. Even if no more greenhouse gases are added to
the atmosphere, they said, Earth will continue to warm by 1 degree
Fahrenheit over the coming decades, as the heat in the oceans is
released into the air.

Dr. Wielicki said the amount of energy coming from the Sun matched the
gain in heat in the oceans reported by Dr. Hansen. "It is consistent
with the ocean heat storage that the oceanographers are seeing," Dr.
Wielicki said, "and it is consistent with the climate models'
predictions of what the heat storage should be."

Dr. Robert J. Charlson, a professor of atmospheric sciences at the
University of Washington and an author of a commentary that accompanied
the three papers, said, "This set of papers, taken together, calls
attention for more emphasis on research in these topics."

But he added, "Unfortunately, impediments have come up." Four years'
worth of data from the Earth Radiation Budget Satellite is unanalyzed,
he said, because there is no money for scientists to work with it.

Another satellite, the Deep Space Climate Observatory, which was
scheduled to be launched on a space shuttle, awaits in storage. Proposed
budget cuts in earth science research at NASA could limit the analysis
of data from other satellites, Dr. Charlson said.

--
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-- e-meil: Remove FreeLunch.

From: "Alan Browne"

|
| Per the NYT, the amount of sunlight reaching the ground has been
| increasing over the past 10 year or so reversing a dimming trend.
| (Local dimness in Hong Kong/India remain).
|
| http://www.nytimes.com/2005/05/06/science/06bright.html
|
| May 6, 2005
| Earth Has Become Brighter, but No One Is Sure Why
| By KENNETH CHANG
|
| Reversing a decades-long trend toward "global dimming," Earth's surface
| has become brighter since 1990, scientists are reporting today.
|
| The brightening means that more sunlight - and thus more heat - is
| reaching the ground. That could partly explain the record-high global
| temperatures reported in the late 1990's, and it could accelerate the
| planet's warming trend.
|
| "We see the dimming is no longer there," said Dr. Martin Wild, a
| climatologist at the Swiss Federal Institute of Technology in Zurich and
| the lead author of one of three papers analyzing sunlight that appear in
| today's issue of the journal Science. "If anything, there is a brightening."
|
| Some scientists have reported that from 1960 to 1990, the amount of
| sunshine reaching the ground decreased at a rate of 2 percent to 3
| percent per decade.
|
| In some places, the brightening of the 1990's has more than offset the
| dimming, Dr. Wild said. In other places, like Hong Kong, which lost more
| than a third of its sunlight, the dimming has leveled off, but skies
| remain darker than in the past. In a few places, like India, the dimming
| trend continues, he said.
|
| The new papers also call attention to a major gap in the understanding
| of climate. Scientists do not exactly know what caused the dimming and
| the brightening, or how they affect the rest of the climate system.
|
| Earth reflects about 30 percent of the incoming sunlight back into
| space. Slight changes in the reflectivity, possibly caused by changes in
| cloud cover and air pollution, can have as much impact on the climate as
| heat-trapping greenhouse gases like carbon dioxide.
|
| Some scientists say that the dimming and the brightening might explain
| why for many years temperatures on Earth lagged what was predicted by
| many climate models and then shot upward more recently.
|
| "I think what could have happened is the dimming between the 60's and
| 80's counteracted the greenhouse effect," Dr. Wild said. "When the
| dimming faded, the effects of the greenhouse gases became more evident.
| There is no masking by the dimming anymore."
|
| But Dr. Rachel T. Pinker, a professor of meteorology at the University
| of Maryland who led the team that wrote one of the other papers, said
| the picture might not be so simple. More sunlight should increase
| evaporation rates, leading to more clouds, and the additional cloud
| cover could then increase Earth's reflectivity, limiting the warming effect.
|
| "I think that's a complex issue," Dr. Pinker said. "There are many
| feedbacks involved."
|
| The findings of Dr. Wild and his colleagues are based on data through
| 2001 from a network of ground-based sensors that directly measure the
| sunlight hitting the ground. But the sensors are not evenly distributed,
| with the greatest number in Europe, few in Africa and South America, and
| none covering the 70 percent of Earth's surface that is water.
|
| Dr. Pinker's team analyzed satellite data from 1983 to 2001 that covered
| the globe. Its findings about brightening, which basically agree with
| Dr. Wild's, rely on computer models to estimate how much sunlight
| reaches the surface.
|
| Finally, a team led by Dr. Bruce A. Wielicki of NASA's Langley Research
| Center in Virginia reports that measurements from the agency's Aqua
| satellite show a slight decrease in the amount of light reflected off
| Earth since 2000, which corresponds to a brightening on the surface.
|
| The NASA findings conflict with measurements, reported last year,
| suggesting that Earth had resumed dimming since 2000. Those measurements
| looked at the illumination of the dark side of the Moon by light
| reflected off Earth.
|
| Dr. Philip R. Goode, a professor of physics at the New Jersey Institute
| of Technology who was one of the researchers behind last year's report,
| said it was not clear why the findings differed so markedly. "We've been
| working with them to understand the origins of the differences," Dr.
| Goode said of the Wielicki group.
|
| Dr. Wielicki said his data supported a report last month by a team led
| by Dr. James E. Hansen of the Goddard Institute for Space Studies in New
| York. In a paper published on Science's Web site, Dr. Hansen and his
| colleagues said much of the excess heat generated by global warming has
| been stored in the oceans. Even if no more greenhouse gases are added to
| the atmosphere, they said, Earth will continue to warm by 1 degree
| Fahrenheit over the coming decades, as the heat in the oceans is
| released into the air.
|
| Dr. Wielicki said the amount of energy coming from the Sun matched the
| gain in heat in the oceans reported by Dr. Hansen. "It is consistent
| with the ocean heat storage that the oceanographers are seeing," Dr.
| Wielicki said, "and it is consistent with the climate models'
| predictions of what the heat storage should be."
|
| Dr. Robert J. Charlson, a professor of atmospheric sciences at the
| University of Washington and an author of a commentary that accompanied
| the three papers, said, "This set of papers, taken together, calls
| attention for more emphasis on research in these topics."
|
| But he added, "Unfortunately, impediments have come up." Four years'
| worth of data from the Earth Radiation Budget Satellite is unanalyzed,
| he said, because there is no money for scientists to work with it.
|
| Another satellite, the Deep Space Climate Observatory, which was
| scheduled to be launched on a space shuttle, awaits in storage. Proposed
| budget cuts in earth science research at NASA could limit the analysis
| of data from other satellites, Dr. Charlson said.
|
| --
| -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
| -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
| -- [SI] gallery & rulz: http://www.pbase.com/shootin
| -- e-meil: Remove FreeLunch.

It's prabably due to the erruption of Mount Pinatubo in the Philippines mid '91. That was a
major erruption, It dropped the avg. Earth temperature and blocked a small percentage of
light from reaching the earth due to the large quantity of dust thrown into the upper
atmosphere.

--
Dave
http://www.claymania.com/removal-trojan-adware.html
http://www.ik-cs.com/got-a-virus.htm

"David H. Lipman" wrote in message
news:QtOee.124$_g1.26@trnddc04...
[SNIP]

It's prabably due to the erruption of Mount Pinatubo in the
Philippines mid '91. That was a major erruption, It dropped the avg.
Earth temperature and blocked a small percentage of light from
reaching the earth due to the large quantity of dust thrown into the
upper atmosphere.


There was an almost immediate, and statistically significant, rise in
average light levels all over North America in the three days after 9/11 -
so I think the dimming is due to air pollution. Air travel is the single
most air-polluting thing man does, and the grounding of flights seems to
have had an almost instant impact. Bad news either way.


Peter

"Alan Browne" wrote in message
.. .
[SNIP]

Dr. Robert J. Charlson, a professor of atmospheric sciences at the
University of Washington and an author of a commentary that
accompanied the three papers, said, "This set of papers, taken
together, calls attention for more emphasis on research in these
topics."

But he added, "Unfortunately, impediments have come up." Four
years' worth of data from the Earth Radiation Budget Satellite is
unanalyzed, he said, because there is no money for scientists to work
with it.

Another satellite, the Deep Space Climate Observatory, which was
scheduled to be launched on a space shuttle, awaits in storage.
Proposed budget cuts in earth science research at NASA could limit
the analysis of data from other satellites, Dr. Charlson said.


Funny how the most spendthift administration the US has ever had wants to
make cuts in those programmes that might reveal the facts that are
unpapteable to their pro-oil and never-mind-about-climate-change agenda...

;-)


Peter

David H. Lipman wrote:


It's prabably due to the erruption of Mount Pinatubo in the Philippines mid '91. That was a
major erruption, It dropped the avg. Earth temperature and blocked a small percentage of
light from reaching the earth due to the large quantity of dust thrown into the upper
atmosphere.

The article states that they're trying to figure out the "why".

Cheers,
Alan

PS: A little snipping would have gone a long way there David.


--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.

Bandicoot wrote:

There was an almost immediate, and statistically significant, rise in
average light levels all over North America in the three days after 9/11 -
so I think the dimming is due to air pollution. Air travel is the single
most air-polluting thing man does, and the grounding of flights seems to
have had an almost instant impact. Bad news either way.

There was a similar drop in measured air pollution following the
blackout of the northeast a couple years ago. A lot of coal is used in
places like Ohio and surrounds to move electrons.

Cheers,
Alan


--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.

Bandicoot wrote:

Funny how the most spendthift administration the US has ever had wants to
make cuts in those programmes that might reveal the facts that are
unpapteable to their pro-oil and never-mind-about-climate-change agenda...

Never get between a failed oilman and reality.


--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.

From: "Alan Browne"


|
| The article states that they're trying to figure out the "why".
|
| Cheers,
| Alan
|
| PS: A little snipping would have gone a long way there David.
|
| --
| -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
| -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
| -- [SI] gallery & rulz: http://www.pbase.com/shootin
| -- e-meil: Remove FreeLunch.

Considering it was a 1st level quote I didn't think snipping was warranted.

--
Dave
http://www.claymania.com/removal-trojan-adware.html
http://www.ik-cs.com/got-a-virus.htm

From: "Bandicoot"


| There was an almost immediate, and statistically significant, rise in
| average light levels all over North America in the three days after 9/11 -
| so I think the dimming is due to air pollution. Air travel is the single
| most air-polluting thing man does, and the grounding of flights seems to
| have had an almost instant impact. Bad news either way.
|
| Peter
|

Please show me that information.

--
Dave
http://www.claymania.com/removal-trojan-adware.html
http://www.ik-cs.com/got-a-virus.htm

Bandicoot wrote:
"Alan Browne" wrote in message
.. .
[SNIP]

Dr. Robert J. Charlson, a professor of atmospheric sciences at the
University of Washington and an author of a commentary that
accompanied the three papers, said, "This set of papers, taken
together, calls attention for more emphasis on research in these
topics."

But he added, "Unfortunately, impediments have come up." Four
years' worth of data from the Earth Radiation Budget Satellite is
unanalyzed, he said, because there is no money for scientists to work
with it.

Another satellite, the Deep Space Climate Observatory, which was
scheduled to be launched on a space shuttle, awaits in storage.
Proposed budget cuts in earth science research at NASA could limit
the analysis of data from other satellites, Dr. Charlson said.



Funny how the most spendthift administration the US has ever had wants to
make cuts in those programmes that might reveal the facts that are
unpapteable to their pro-oil and never-mind-about-climate-change agenda...

;-)


Peter


A redneck is not a redneck without a rifle and a V8 truck...