I thought TangoMan would find this article amusing. It describes a
situation that is bad for PV and is potentially argument for SSPS or
other large space developments (as well as maybe for burning more fossil
fuels). I'm sure anti-environmentalists out there will have some fun
with it. :-)

http://www.guardian.co.uk/life/feature/story/0,13026,1108853,00.html

Excerpt:

"Each year less light reaches the surface of the Earth. No one is sure
what's causing 'global dimming' - or what it means for the future. In
fact most scientists have never heard of it.

In 1985, a geography researcher called Atsumu Ohmura at the Swiss
Federal Institute of Technology got the shock of his life. As part of
his studies into climate and atmospheric radiation, Ohmura was checking
levels of sunlight recorded around Europe when he made an astonishing
discovery. It was too dark. Compared to similar measurements recorded by
his predecessors in the 1960s, Ohmura's results suggested that levels of
solar radiation striking the Earth's surface had declined by more than
10% in three decades. Sunshine, it seemed, was on the way out.

The finding went against all scientific thinking. By the mid-80s there
was undeniable evidence that our planet was getting hotter, so the idea
of reduced solar radiation - the Earth's only external source of heat -
just didn't fit. And a massive 10% shift in only 30 years? Ohmura
himself had a hard time accepting it. "I was shocked. The difference was
so big that I just could not believe it," he says. Neither could anyone
else. When Ohmura eventually published his discovery in 1989 the science
world was distinctly unimpressed. "It was ignored," he says.

It turns out that Ohmura was the first to document a dramatic effect
that scientists are now calling "global dimming". Records show that over
the past 50 years the average amount of sunlight reaching the ground has
gone down by almost 3% a decade. It's too small an effect to see with
the naked eye, but it has implications for everything from climate
change to solar power and even the future sustainability of plant
photosynthesis. In fact, global dimming seems to be so important that
you're probably wondering why you've never heard of it before. Well
don't worry, you're in good company. Many climate experts haven't heard
of it either, the media has not picked up on it, and it doesn't even
appear in the reports of the Intergovernmental Panel on Climate Change
(IPCC).

"It's an extraordinary thing that for some reason this hasn't penetrated
even into the thinking of the people looking at global climate change,"
says Graham Farquhar, a climate scientist at the Australian National
University in Canberra. "It's actually quite a big deal and I think
you'll see a lot more people referring to it.""

Discussed and first seen at:
http://science.slashdot.org/article.pl?sid/12/18/1350226&mode=thread&tid4&threshold=2

======

I read a Scientific American article a decade or so ago that argued the
Sun has been increasing in brightness over its life, and C02 in the
Earth's atmosphere strangely has been decreasing enough year to year to
offset this over the past few billion years (from an initially very high
level), but that in about 100 million years or so this effect would end
(when C02 reached zero) and the Earth would soon become uninhabitably
warm. [So maybe Gaia or the Bacterianet decided to risk making smart
tool using creatures to make daughter space habitats? :-)] Ice ages and
such were smaller cycles within this larger trend. Unfortunately, adding
CO2 to counter a local ice age won't help in the long term as this will
just heat up things more as the sun continues to brighten.

Anyway, I'll be interested to see how this solar dimming thing plays out...

I'm definitely all for considering solar shades or mirrors placed in
orbit around Earth long term if this is a big problem. If people want to
make a case for global presence in space managed by a big centralized
concern for addressing a specific short term global problem to drive the
development of space habitats for orbital construction, this might be it
(more than SSPS IMHO).

--Paul Fernhout

> I thought TangoMan would find this article amusing. It describes a
> situation that is bad for PV and is potentially argument for SSPS or
> other large space developments (as well as maybe for burning more fossil
> fuels). I'm sure anti-environmentalists out there will have some fun
> with it. :-)
>
> http://www.guardian.co.uk/life/feature/story/0,13026,1108853,00.html

Oops, looked like I missed this part of the story in my eagerness to
post this (and my having heard of sun output changes):

"So what causes global dimming? The first thing to say is that it's
nothing to do with changes in the amount of radiation arriving from the
sun. Although that varies as the sun's activity rises and falls and the
Earth moves closer or further away, the global dimming effect is much,
much larger and the opposite of what would be expected given there has
been a general increase in overall solar radiation over the past 150
years. That means something must have happened to the Earth's atmosphere
to stop the arriving sunlight penetrating. The few experts who have
studied the effect believe it's down to air pollution. Tiny particles of
soot or chemical compounds like sulphates reflect sunlight and they also
promote the formation of bigger, longer lasting clouds. "The cloudy
times are getting darker," says Cohen, at the Volcani Centre. "If it's
cloudy then it's darker, but when it's sunny things haven't changed much.""

So, maybe some of those environmentalists were right after all about the
"precautionary principle" and air pollution? :-)
http://www.biotech-info.net/precautionary.html
http://www.sehn.org/precaution.html

Anyway, still it is another argument for TangoMan & SSPS -- or for a
crash program in R&D in zero emissions manufacturing and local PV. :-)
In any case, it's a strong argument for doing something sooner rather
than later about fossil fuel use and/or air pollution.

[And long term, a change in solar output upward (over millions of years)
is still an argument for sun shades for the Earth. But short term, it
looks like mirrors might be problematical -- they would bring in more
light, but would also heat things up if the problem is air pollution.]

--Paul Fernhout

--- In ssi_list@... "Paul D. Fernhout"

> I thought TangoMan would find this article amusing.

Not amusing, but very interesting. I'd never heard of this before.

> I'm sure anti-environmentalists out there will have some fun
> with it. :-)

Maybe as a stick to poke at the bad science of the climatologists
who didn't know it was going in, but if it is particulate pollution
that is causing the dimming, it'll be industry that is to blame. All
in all, I'd say it's a wash for the anti-environmentalists. Heads or
tails, they lose.

From the article:

"Many climate experts haven't heard of it either, the media has not
picked up on it, and it doesn't even appear in the reports of the
Intergovernmental Panel on Climate Change (IPCC)."

Doesn't it strike you as odd that many haven't heard of it before
but they can speak with a high degree of certainty about their
models, models which I might add don't account for this process.
Isn't it a climatologist's business to know this kind of thing?

"The problem is that most of the climate scientists who saw the
reports simply didn't believe them. "

On what basis do they not believe the reports? Gut feel? Or an
invalidation of the results through a process of seeking to
reproduce the experiment? No, that would take too much time, better
to just go with gut feel. Yeah, that's much better than scientific
method.

"This forced more scientists to sit up and take notice, though some
still refused to accept the change was real, and instead blamed it
on inaccurate recording equipment."

On what basis do they make the claim that the results are equipment
error? Sounds like they're just shooting off their mouth. That's not
to say that they'r wrong or that this couldn't be a source of error,
but they haven't proved it. They're substituting a hypothesis for a
testable conclusion.

All in all, a very thought provoking post. Thanks Paul. But it
doesn't bolster my confidence in the professionalism of
environmental scientists if this process is unknown to many of them.
For them to claim their climate models are accurate smacks of hubris.

TangoMan

that may explain what causes Ice ages, except of course we should still have
to find out what causes the dimming in the first place... :)

Cheers,

Claudio

>
> I thought TangoMan would find this article amusing. It describes a
> situation that is bad for PV and is potentially argument for SSPS or
> other large space developments (as well as maybe for burning more fossil
> fuels). I'm sure anti-environmentalists out there will have some fun
> with it. :-)
>
> http://www.guardian.co.uk/life/feature/story/0,13026,1108853,00.html
>
> Excerpt:
>
> "Each year less light reaches the surface of the Earth. No one is sure
> what's causing 'global dimming' - or what it means for the future. In
> fact most scientists have never heard of it.
>
> In 1985, a geography researcher called Atsumu Ohmura at the Swiss
> Federal Institute of Technology got the shock of his life. As part of
> his studies into climate and atmospheric radiation, Ohmura was checking
> levels of sunlight recorded around Europe when he made an astonishing
> discovery. It was too dark. Compared to similar measurements recorded by
> his predecessors in the 1960s, Ohmura's results suggested that levels of
> solar radiation striking the Earth's surface had declined by more than
> 10% in three decades. Sunshine, it seemed, was on the way out.
>
> The finding went against all scientific thinking. By the mid-80s there
> was undeniable evidence that our planet was getting hotter, so the idea
> of reduced solar radiation - the Earth's only external source of heat -
> just didn't fit. And a massive 10% shift in only 30 years? Ohmura
> himself had a hard time accepting it. "I was shocked. The difference was
> so big that I just could not believe it," he says. Neither could anyone
> else. When Ohmura eventually published his discovery in 1989 the science
> world was distinctly unimpressed. "It was ignored," he says.
>
> It turns out that Ohmura was the first to document a dramatic effect
> that scientists are now calling "global dimming". Records show that over
> the past 50 years the average amount of sunlight reaching the ground has
> gone down by almost 3% a decade. It's too small an effect to see with
> the naked eye, but it has implications for everything from climate
> change to solar power and even the future sustainability of plant
> photosynthesis. In fact, global dimming seems to be so important that
> you're probably wondering why you've never heard of it before. Well
> don't worry, you're in good company. Many climate experts haven't heard
> of it either, the media has not picked up on it, and it doesn't even
> appear in the reports of the Intergovernmental Panel on Climate Change
> (IPCC).
>
> "It's an extraordinary thing that for some reason this hasn't penetrated
> even into the thinking of the people looking at global climate change,"
> says Graham Farquhar, a climate scientist at the Australian National
> University in Canberra. "It's actually quite a big deal and I think
> you'll see a lot more people referring to it.""
>
> Discussed and first seen at:
> http://science.slashdot.org/article.pl?sid/12/18/1350226&mode=t
hread&tid4&threshold=2

======

I read a Scientific American article a decade or so ago that argued the
Sun has been increasing in brightness over its life, and C02 in the
Earth's atmosphere strangely has been decreasing enough year to year to
offset this over the past few billion years (from an initially very high
level), but that in about 100 million years or so this effect would end
(when C02 reached zero) and the Earth would soon become uninhabitably
warm. [So maybe Gaia or the Bacterianet decided to risk making smart
tool using creatures to make daughter space habitats? :-)] Ice ages and
such were smaller cycles within this larger trend. Unfortunately, adding
CO2 to counter a local ice age won't help in the long term as this will
just heat up things more as the sun continues to brighten.

Anyway, I'll be interested to see how this solar dimming thing plays out...

I'm definitely all for considering solar shades or mirrors placed in
orbit around Earth long term if this is a big problem. If people want to
make a case for global presence in space managed by a big centralized
concern for addressing a specific short term global problem to drive the
development of space habitats for orbital construction, this might be it
(more than SSPS IMHO).

--Paul Fernhout

--- In ssi_list@... "Paul D. Fernhout"

> So, maybe some of those environmentalists were right after all
> about the "precautionary principle" and air pollution? :-)
> http://www.biotech-info.net/precautionary.html
> http://www.sehn.org/precaution.html

Maybe they were. It's hard to tell at the stage of hypothesis.

It might be interesting to speculate about the causes.

* Particulates in the air.
* Higher water vapor content leading to increased albedo of clouds.
* Earth in a zone of more meteorites which burn up in the atmosphere
and add their particulates.

You know, it might be interesting to have a multi-year study of
light penetration at varying heights. Send up high altitude balloons
to measure light intensity at various heights. Then over a long
enough period see whether light is dropping off uniformly of is
blocking at a certain region. Proceed with further experimentation
from those conclusions.

TangoMan

Hi All,

Please pardon my long post.

Here is my 'unscientific' reasoning on the subject of
dimming for all that are interested.

I took on the problem in college 20 years go of why
Antarctica was largely ice free 20 million years ago
while the ancestors for humans were scratching out a
living in Africa. My premise is that the world did
not get dramatically hotter (or it would have shown up
in other sediments) so it must have has much better
circulation between the poles and tropics.

This fits into a very simple model that heat seeks the
poles in a giant convection cell not too unlike what
can be simulated in an ordinary terrarium at home.
The trick is that the world is curved (meaning that
things spin if they travel North or South) and the
ratio of height to length is about 1/500 give or take
(20km by 10,000km).

In most weather literature up to the 80's the global
weather pattern is displayed as having three cells of
air rising at the Equator, sinking at 30 degress North
(Sahara, Mojave deserts) rising at 60 degrees and
sinking at the pole. Add in that moisture really
cannot cross the himalayan - Tibet complex of mountain
ranges and you have a really simplified world weather
diagram or so people thought.

This is what the majority of the big weather
simulations are based on published by a great many
organizations that accuse carbon dioxide as being the
prime greenhouse gas. There is an interesting problem
with these if you examine them as the Sahara was a
grassland as little as 5,000 years ago. How did the
global circulation patterns change so radically 5,000
years ago that air rose at 30 degrees North instead of
consistently sinking as it does now.

Since there was no great change in carbon levels
associated with the drying of the Sahara 5K years ago,
I have never seriously considered carbon dioxide as a
powerful causitive agent in changing global climate.
I reasoned something else has to be at work and the
climate had was far more unstable than most people
gave it credit for.

My focus has been on the plants because of the
behavior in Brazil when they cut down the rainforest
to farm it. As rainforest the are gets some 200
inches a year of rain. As farmland or grassland it is
lucky to get 30 inches of rain. Better yet rainforest
are swathed in clouds which are highly reflective
which contributes to the condensation of rain
droplettes. Grasslands and farmland by comparison are
quite a bit darker and give off significantly less
moisture as evaporation. To me this means that the
clouds follow the plants.

The ancient peoples of the Sahara are depicted as
grazing large herds of animals as a way of life.
Assuming that they grew their herds until the ecology
had trouble supporting them then you are going to see
a great deal of range destruction - denuded forests,
etc. As they did this did the clouds move North and
gradually turn the place into a desert? There is
quite a bit of evidence that the early peoples did
just that and everywhere they lived in numbers the
forests and soil was damaged. Look at modern rocky
Palestine or Greece and noticed how the ancient
stories talk of forests.

So I conjecture that cutting down forests and turning
grassland into dark fields will yield a huge change in
the local climate. Add in that you incinerated them
with fire and you yield billions of tones of soot and
fine dirt in the atmosphere which has as big a heat
signature as anybody could ever wish for. This is the
fog of pollution that surrounds many areas of the
world - part Nitrogen compounds, part soot, part
water, part dirt. All of it has a vast heat
absorption ability.

I live in Seattle area and noticed one summer day that
the hood of my white car looked a bit pink. There had
been a duststorm the week before in rural China and it
was reported to have reached the US. I saw that as a
measure the trails of pollution (described above)
extended out thousands of miles from the source. If
dust could cross the Pacific then dirt and various
other things smaller would do so even easier.

The question was raised of why I had not seen this in
the global warming calculations. The answer is that
the majority of this dust is rained out of the
atmosphere. This makes sense only it takes a runway
of several thousand miles to do so. Better yet dirt
and soot make for excellent water dropplet nucleation.
What better way to seed rast amounts of clouds.

This added the idea that the cloud cover has been
reduced over and to the East of the more densly
populated parts of the world. That would mean that a
lot more sunlight is getting through to the ocean and
ground than it ever did except that it isn't according
to the mentioned study on dimming. I see that the
heat got lower in the atmosphere than before and got
absorbed quickly. Hot air rises very quickly meaning
that the heat would hang out at the top of the
atmosphere and not the bottom. At high altitudes all
sorts of things would happen so it does not surprise
me that dimming has been recorded.

Where the heat has shown up is at the polar regions
where it is deposited by the convection cell.
Northern polar ice has thinned some 40% in the last 40
years as recorded in annual sub logs that rise through
the icepack in mid winter. Better yet there is an
increase incidence of fogs forming in wintertime.
Fogs are highly insulating and reflective meaning that
the pole does not radiate as much heat into space as
it once did. All around the Arctic the permafrost is
melting as if a giant heat lamp had been pointed at
the region. There is no similar effect in Antarctica
to match as far as I know which makes sense as most
people in the world live in the Northern Hemisphere.

So it sure looks to me that the big change in the
world would be to move the plants from the tropics to
the poles as the clouds would follow. The heat
radiated from the poles would be less and what was
received in the tropics would rise very quickly. I
saw a strange confirmation of this in the surprise
freezing of the monarch butterfies in Mexico one
winter day. The temperature unexpectedly plunged to
10 degrees F which was a record by 20 degress. This
made sense as a area of polar air had stayed intact on
the top of the Southern directed air cell between 60
and 30 degrees latitude and simply dropped out of a
clear sky on the jungle.

I hope this has made sense as I don't write that much
and often leave out relevant details. Here is the
punchline.

The world is rapidly heating up as measured by wind
velocity (air moving between pole and equator) and the
amount of water moved (evaporated or deposited). I do
not use actual measured temperature to mean much as it
is measured at the bottom of the air column and not at
the top where all the action is. The irony fo this
assertion is that it will become more even between
Alaska and Florida for temperature extremes as the air
moves faster to equalize things. With the longer
growing season at the poles forests are forming where
is was priorly a rocky and desolate wasteland making
it darker and more heat absorbant.

The easiest confirmation is that number of exceptional
storms, droughts, heatwaves, coldfronts will increase
as the polar fronts go increasingly South and warm
fronts North. With more energy in the atmosphere you
will see lower low pressures and more coherent high
pressure systems. I see all of these things though
many do not or claim not to.

This fits nicely with the arguments of the Skeptical
Environmentalists as he points out that there are more
forests now than there were a hundred years ago. I
see them forming where you don't want them to form
namely the polar regions. Various global warming
texts have indicated that the average cloud cover of
the earth has stayed roughly the same over time. I
see that moving the clouds from the tropics to the
polar regions will insulate where you are cooling off
and increase where you are picking up heat.

Even the satellites may not show changes in the global
humidity as it is there to carry heat from one place
to another and does not have to increase in a snapshot
view to have a big effect. For sure the polar bears
will notice as their habitat becomes unlivable. A
white bear cannot hide on land and will starve.

My conjecture is that the Northern ice pack will
completely melt off in the summers in as little as 20
years leading to an area the size of China going from
essentially white to black as far as heat absorbtion.
This is to say that the system is tapping a reserve of
cold that once gone will lead to a strikingly
different weather pattern than anyone seen before.
Where this relates to space development I do not know.
What comes next I am sure it will.

Once you melt off the Northern icecap, the increased
heat will seek the remaining icecap namely Antarctica.
At an average height of several thousand meters, it
is currently inplausible that heat would cause the
bulk of Antarctica to melt. Unfortunately the breakup
of the Larson sheets pointed to a dynamic that you do
not need to melt the glacier to remove it - you only
need to melt the top of it for two weeks in five
consecutive years. If warm fronts start riding up on
Antarctica in 30 years the Ross iceshelf may not be as
stable as everybody claims. If I am right and it is
not then you have a real potential for sea level rise.

To combat sealevel rise there is not enough energy on
the earth in any useable form to make enough concrete
to protect the land from flooding. To do this you
will have to get it from something like SPS built on
such a monumental scale that it dwarfs all prior human
accomplishments. With this kind of power and the
manufacturing base to produce it all the material
problems of the earth are solvable.

I sincerely hope that people recognize the changes
around them and put in motion such a solution for the
day that they will need it.

Sincerely, Thor Olson

> Hi All,
>
> Please pardon my long post.
>
> Here is my 'unscientific' reasoning on the subject of
> dimming for all that are interested.
>

Thanks for the detailed post. I'd like to respond in detail but am
currently pressed for time.

I look forward to reading all related comments over the next few
weeks.

Happy Holidays to all.

TangoMan