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Global Dimming
wiredog writes "The Guardian reports on research which shows that the amount of sunlight reaching the Earth's surface has decreased by 10% in 30 years. This has implications for global warming models and, especially, agricultural output."
I would say this is directly linked to our obesity problems
badum DUM
This is not a sig
my landlord told me not to touch that dial on the wall, but i couldn't resist
i'll set it back to the way i found it
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
of Global Warming, we have to worry about Global Cooling. Is that why it is 45F out in S. Florida? :-)
Since agricultural output has already multipled and skyrocketed over the years thanks to technology and IPM, this isn't necessarily a burning crisis..
Hokey statistics and ancient misconceptions are no match for a good thought in your head, kid!
This makes me wonder about the drive towards a hydrogen-powered economy. All that water vapour coming out of car exhaust pipes, etc. Probably a better form of pollution from a health perspective, but will it also result in limiting sun light or producing clouds that trap heat?
I always felt that the world was a brighter place when I was a kid, now I have proof!
Surely the price will go down, as there is less demand. I would have thought it would be a better idea to invest in tanning salons.
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. By David Adam
Thursday December 18, 2003
The Guardian
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."
That's not to say that the effect has gone unnoticed. Although Ohmura was the first to report global dimming, he wasn't alone. In fact, the scientific record now shows several other research papers published during the 1990s on the subject, all finding that light levels were falling significantly. Among them they reported that sunshine in Ireland was on the wane, that both the Arctic and the Antarctic were getting darker and that light in Japan, the supposed land of the rising sun, was actually falling. Most startling of all was the discovery that levels of solar radiation reaching parts of the former Soviet Union had gone down almost 20% between 1960 and 1987.
The problem is that most of the climate scientists who saw the reports simply didn't believe them. "It's an uncomfortable one," says Gerald Stanhill, who published many of these early papers and coined the phrase global dimming. "The first reaction has always been that the effect is much too big, I don't believe it and if it's true then why has nobody reported it before."
That began to change in 2001, when Stanhill and his colleague Shabtai Cohen at the Volcani Centre in Bet Dagan, Israel collected all the available evidence together and proved that, on average, records showed that the amount of solar radiation reaching the Earth's surface had gone down by between 0.23 and 0.32% each year from 1958 to 1992.
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 inacc
No, thats what is probably causing this....
The light from the sun is absorbed by the junk we blow into the atmosphere and thus doesn't reach earth. The energy is still absorbed by the earth as a whole....
Jeroen
Secure messaging: http://quickmsg.vreeken.net/
So the pollution that pumps out of power stations is making it too dark to switch to solar power. How convenient.
If you read the article, global dimming does not equal global cooling. It is, in fact, compatible with global warming. The theory is either that (as stated above) atmospheric pollutants are blocking sunlight, or that global warming is resulting in more water vapour being carried in the air - in other words, it's getting cloudier.
evil math within Nature's Cubic Creation!
There is no accurate model of the environment. Worse, its obvious a few of these guys have a serious attitude problem.
What it comes down to is, whose policies are most in favor with the scientific community will get results from that community supporting their position. Screw the fact they don't have all the facts, it doesn't prevent either camp from making claims.
Its Global Warming this pas 15 years, before then it was Global Cooling.
Environmentalism is much more about ideaology than realism.
* Winners compare their achievements to their goals, losers compare theirs to that of others.
We can thus conclude that we know nothing. Weather patterns haven't been recorded for a long enough time to make any valid long time prediction of such things as global warming or freezing. Once they manage to consistently predict tomorrows weather successfully they may go onwards and claim they have a clue how the weather will be 100 years from now. For those screaming "Kyoto!" etc: yes, reducing pollution is good and should be something to strive for for every somewhat intelligent human being, but I wouldn't draw a conclusion about global warming from what was presented yet.
Quite weird - there was an elderly farmer saying much the same thing this morning on my bus to work.
I'm pretty sure he wasn't a guardian reader, it's just something he'd noticed over the years.
At the time, I thought he was talking crazy talk...
research which shows that the amount of sunlight reaching the Earth's surface has decreased by 10%
Maybe we already have that considering that the study has a margin of error of 10%
No, dimming and warmimg are not mutually exclusive... They go together quite happily...
Less light to the ground does not mean a colder climate, the heath from the sun is simply absorbed somewhere else like in an atmosphere full of greenhouse gasses.
The global warming fad won't be put away. The new data will simply be integrated into the models and will likely proove we screwed our environment up even further than we thought.
Jeroen
Secure messaging: http://quickmsg.vreeken.net/
I suspect that some of this global dimming is due to pollution from sulfates (coal), jet contrails, and dust from wind-borne erosion. Sulfate and particulate pollution provides nice nucleation sites for cloud formation. These pollution-created artificial clouds probably reduce global warming (the article mentions this effect and a correlated decrease in cloudiness and increase in temperatures in the 1990s).
The scary part comes if we reduce these forms of pollution, reduce cloudiness, and thus accelerate global warming. Whether we like it or not, humanity is changing the climate -- as attractive as it seems, preservation is impossible. At this point, it might be better to think about climate engineering -- deciding how we want to change the climate rather than holding on to the false hope that we can avoid changing the climate.
Two wrongs don't make a right, but three lefts do.
sounds like complete bull to me... If ANYTHING there would be MORE now since the 70's when they implemented all the anti-smog and pollution laws. Whoever came up with these results is likely just trying to make a name for themself. Sounds like a pathetic attempt...
... the math ain't hard.
Did you RTFA? That's almost exactly the reaction a lot of senior scientists had, but it looks like the evidence is pretty overwhelming. (With the usual caveats about popular journalism being hard to trust when it comes to science reporting, etc.) The thing about pollution laws is, they've helped a lot, but a) a lot of pollution comes from Third World countries that have no pollution laws, or don't enforce the ones they have, and b) the effects of the laws have been pretty much overwhelmed by the fact that we have a lot more people now than we did two or three decades ago.
We've seen this on a small scale where I live, in Denver, the city that gave the world the phrase "brown cloud." When I was a kid in the Seventies, the population of the Denver metro area was about half what it is now, and the pollution was just terrible. During the Eighties, as tougher laws kicked in (AFAIK, Colorado was the second state in the western US, after California, to really get serious about this) things improved dramatically. But through the Nineties, air quality started to get worse again, and we're now just about back to where we were when the laws came into effect. Halve the average emissions, double the population
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
Look, while there are plenty of documented cases of faking data, I think this is the exception, rather than the rule. Most scientists aren't in it for the money; if they were, they wouldn't bother being scientists- they'd become sell-outs like myself, or study a more lucrative field like economics.
As for your logic that this doesn't make sense, consider the possibility that the increase in global sulphur emissions from, say, 1940 to 1990, induced enough reduced sunlight to roughly offset the potential warming effect of CO2 emissions, but since 1990 CO2 emissions have increased more rapidly as advanced economies move to less carbon-intensive (coal->oil->nat. gas) fuels. I don't have the data to back this up, but it's one possible reason that the observed warming patterns don't match what you might expect from increased CO2 concentrations alone (global warming critics love to point out that there was disproportionately more warming in the 1st half of the century than the 2nd).
I admit that this is a half-cocked theory. But my point is that you failed to understand all of the factors at hand. Climate science is complicated; that's whay no one knows for sure what the f--- is going on.
Simple Unexpected Concrete Credible Emotional Stories
Didn't you people see Animatrix? We HAD to do this to prevent the robot takeover, but it will only cause them to come after us for batteries.
So, if I get this right, global dimming and global warming are compatible, possibly complementary phenomena. This would mean that the world is getting warmer & darker.
Now, I'm not a scientist, but this sort of implies to me that things will get more humid as well. So, we're setting up for living in a big ole' sauna. So, let's look at the ups and downs:
Good: We'll all have great skin for starts.
Bad: Lots of very fat men walking around in flip-flops with small towels around their waists.
Good: Girls will wear less clothing to cope with the heat & humidity--we'll have a population of nice-skinned chicks dressed like the love-slaves from planet Triton. Misquoting Mary Carey: "Global warming? Never heard of it, but I guess we'll all have to wear less". Woo!
Bad: Killer hangovers, massive ring around the collar.
Cole's Law: Thinly sliced cabbage
Every day, we get enough sunlight to power 27 years worth of the world's energy needs. Now, I thought about the implications of that. Obviously, we couldn't absorb/store the entire amount, but if we could put a dent in it, we'd have some global cooling. That is what this article is about.
On a similar note, the US could obtain all energy from the sun if it were to install a 200 mile square solar installation (assuming 15 percent efficiency... easily doable today). I say, put a dime of tax on each gallon of gas and use this money to subsidize solar generation - one of the only energy producers out there with net positive energy (more energy produced in the cell's lifetime than it takes to produce the cell itself). Hydro, wind and solar... I can't wait for the day.
On yet another related note, I'm in the process of building a solar/NiMH PC. I'm simply going to use store-bought NiMH rechargables to store excess daytime solar input. It certainly won't be cost effective but it'll be pretty high on the geek factor.
Life is the leading cause of death in America.
Don't kid yourself. The US is responsible for a very large chunk of the greenhouse gas output of the world. It is something like 40%. That is despite the fact that the US has around 5% of the world's population.
Don't forget that average fuel economy of cars sold in the US is at its lowest level in 20 years. Think about that for a moment. The average car sold today has roughly the same fuel economy as a car sold in 1983! Why? Looser resrtictions on "light trucks", because they were used for work purposes. Then the automakers realized they could make glorified station wagons and call them SUVs and sell them as "light trucks", as though they were being used for work. Heck, the Chevy Suburban is so big that it isn't even considered a "light truck" and is therefore not subject to fuel economy regulations at all. For fuel economy purposes, a Suburban is treated as though it were the same type of vehicle as a dump truck.
--
The internet is the greatest source of biased information in the history of mankind.
1. In general, studies of this type are very difficult to do. One has to take into account:
-
the non-continuity of the measurements (they're not measuring everywhere, they are probably tending to measure near cities; cities cause definite local effects over time, but they are only a small percentage of Earth's surface area.
- astonishingly few "scientists" actually understand how to use instrumentation. (Yeah, flame me - but it's true - I've done a lot of teaching and mentoring in this area). One of the problems of our age is that we all have access to sophisticated equipment, but few actually know what the results mean.
2. It occurs to me that if the Earth's atmosphere were soaking up all of that energy, astronemers (one group that actually does know how to use instrumentation) would have noticed spectral changes years ago. But we haven't heard from them. (They could be part of a vast right-wing conspiracy to prop up the Bush and Cheney crew, I suppose, and are just not telling us.)3. I haven't done the calculations (has anybody?) but it also occurs to me that if Earth's atmosphere were soaking up all of that energy, there'd be some SERIOUS global warming occuring.
4. In the article, the "discoverer" of our newest Earth-dooming catastrophe seems to indicate that he was amazed to have found this issue in the mid-80's when "there was undeniable evidence that our planet was getting hotter". As some of us will recall, the dominant paradigm in the mid-80's was global cooling. Global cooling in the '80s was as obvious and well-proven as global warming is today. And, actually, diminishing sunlight reaching the Earth would be consistent with global warming (see point 3).
Dimming != Cooling
The article is about less sunlight reaching the earth's surface. Nothing about the earth cooling down....
Lets have an experiment:
1 Take a black (or very dark) plastic bag.
2 Go stand in the sun.
3 Pull the bag over your head (not to tight you are not going for a Darwin Award)
4 Stand for a while
You will notice the following:
1 You don't see much since the sunlight does not reach your eyes. (Lets call this 'dimming')
2 It gets hot in the bag. (Lets call this 'warming')
Conclusion:
You can have dimming and warming at the same time.
Jeroen
Secure messaging: http://quickmsg.vreeken.net/
[...] a lot of pollution comes from Third World countries that have no pollution laws, or don't enforce the ones they have [...]
Yeah, right! Sure it's those ultra-developed industries in unregulated Third World countries producing all the polution. I'm sure that the fact that countries like the USA or Russia are conveniently not abiding by the Kyoto Treaty has nothing to do with it.
"Enjoy your job, make lots of money, work within the law. Choose any two."
Actually, when one puts it that way, it doesn't sound too bad ...
So I blame jet airplane contrails.
- "History shows again and again how nature points out the folly of men" -- Blue Oyster Cult, 'Godzilla'
Don't kid yourself. The US is responsible for a very large chunk of the greenhouse gas output of the world. It is something like 40%. That is despite the fact that the US has around 5% of the world's population.
Ok, then just replace "Third World country" by "country whose leader has not been democratically elected", and it again fits...
"This new evidence proves global warming is bunk because now we know the scientists don't know everything."
To me this makes just as much sense as rejecting biology as soon as scientists discover a new species. "See! The proves the bible was right!"
Being bitter is drinking poison and hoping someone else will die
Also, it seems that the assumption has been made that the sun produces constant output. I don't think we can make this assumption. The sun, as a system, is way bigger than our atmosphere. Until we have thousands of years worth of data, observed from outside the atmosphere, we can't prove that solar radiation is a constant. In fact, since solar flares temporarily increase solar output, you could postulate that thousand year trends in flare frequency and magnitude could affect the overall output of the sun.
So, while global dimming may or may not affect us in the short term (on the scale of centuries) and pollution is still bad (again very long term effects are unrecorded, but it's obviously very bad in the short term (again measured in centuries) and it is ugly), I'm still not all that concerned that the world is going to ice over or boil away any time soon.
i don't like my old sig.
The important point here is: we are altering the planetary system, but can not predict the effects.
There is no doubt that we are changing the planetary system. If nothing else, CO2 concentrations are rising dramatically and human activity is definitely the culprit. And global temperatures are definitely rising. Humans may or may not be the culprit, but a back-of-the-envelope calculation suggests that more CO2 should cause higher temps.
The problem is that we can't predict the effects of these changes. It isn't like there's a global thermostat that we can turn up or down a half-degree by altering our industrial output. Rather, it is like throwing random chemicals into a bowl in a closed room, hoping you don't create toxic fumes. You might, you might not, but you don't know one way or the other, and you can't get out in any case.
I spent several months looking into climate models and concluded that they're complete bunk. We can't predict the weather a week out, but people use the very same techniques to "predict" the climate a century out. Consider this: if you believe in a human activity-climate link, then in order to predict climate, you have to predict human activity. So predicting the behavior of the entire world economy is just one small source of the uncertainty in these models! They're garbage! Computer climate models just create a false sense of predictability about climate change.
So this leaves us in a scary place. Here we are on earth. If we screw it up, we have nowhere else to go. We're making changes, but we don't know the effects. Since we don't understand the planetary system, we can't necessarily undo the effects. It's like remodeling an aircraft in flight.
If we make it easier for the stupid people to survive, then of course Global Dimming will occur.
Play Well
You are quite correct; I don't think any educated person would disagree with your assertion that environmentalism is not a science. :
From WordNet (r) 2.0
environmentalism
n 1: the philosophical doctrine that environment is more
important than heredity in determining intellectual
growth [ant: hereditarianism]
2: the activity of protecting the environemnt from pollution or
destruction
The inductive approaches to physics, biology, and chemistry are sciences. These form the basis of all scientific research concerning the environment of our planet.
To learn more about the scientific method you will want to read this article about Francis Bacon and his advocacy of an inductive method (which is now generally called "the scientific method"), and a more detailed article describing the scientific method in some detail.
I'm no climate scientist, or climate engineer, but it seems to me that dark |= cold. A greenhouse can be dark but hot. The gasses keep in the heat, yet keep out the light. Venus springs to mind.
Scientists have been debating this one quite a bit -- whether cloud's reflection of the sun light creates more cooling than the cloud's night-time heat-trapping abilities. The suspension of airtravel around 9-11 gave scientists a chance to study this. They found that the absence of contrails created pronounced higher daytime highs and slightly lower nighttime lows. At least for contrails, the net effect seems to be a reduction in average temperture.
Admittedly, this is only a single study. The point is that intuitions about clouds reflecting energy vs. greenhouses retaining energy only provide insight into potential qualititive outcomes. The real quantitative answer may be different depending on the numerical balance of all the effects.
Two wrongs don't make a right, but three lefts do.
You are correct -- your meteorology is not that great, and your physics is rusty.
Bemopolis
"I guess the moral of the story is, don't paint your airship with rocket fuel." -- Addison Bain
Damn it, I knew trying to close that ozone hole was a mistake
Unfortunately, real environmental problems are usually created locally*. Fixing them means taking the economic hit locally -- losing factory jobs in your own city, reducing the fertilizer-driven crop yield on your own farm, having a smaller engine in your own car, whatever.
It's much better to deal with global environmental issues, which are, by definition, somebody else's fault. "It's not me, it's those darned Amazonian loggers! I can't do anything by myself, the world's governments need to get together and make everyone do things differently."
[* important exception: rivers. Rivers carry and in some cases even concentrate pollution from large distances upstream]
initial planning, design, materials and implementation, maintenance and repair...good idea but I doubt it would come close to paying for itself.
Is the juice worth the sqeeze?
I thought for a minute there that "Global Dimming" was referring to the decrease in average human intelligence in proportion to the global increase in lawyers!
Please note here, much of this 10% is being reflected. There are people in this thread pointing out how untrue the observations must be because if 10% of the sun's energy was being absorbed by the atmosphere, the Earth would be getting a heck of a lot warmer than it is. Instead, the Earth should be getting 10% brigher from the moon or anywhere else in space. Particulates are reflecting and clouds are forming (which look very bright to me when I fly over them).
I've been wondering about this. Would global warming end up creating enough clouds to reflect enough energy from the sun that it balances itself out after a few decades? Or will global warming cause an imbalance in the sun's reflected energy after a few decades that causes a swing on the cold side? How much does the CO2 green house effect compare to the particulate / cloud reflector effect?
I wonder if this will have any sort of noticeable effect on Seasonal Affective Disorder. It has been shown that people feel more depressed with less exposure to the sun (this disorder is especially common in winter).
It's funny, everyone talks about how people seem sadder and grumpier "these days". I wonder if there could be an actual link to this "global dimming".
"Reality is merely an illusion, albeit a very persistent one " -Albert Einstein
No, the radioactive elemants in the earth's core did not come from the sun. They formed from the same cloud of gas as the sun did (from the remains of a supernova IIRC).
As to saying that radioactive decay is non-renewable, that is rediculous. It will always be there (unless you're looking at millions/billions of years in the future, and you might as well be worried about the sun burning out or exploding by then. You might as well consider the sun to be non-renewable on that timescale, as well.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
Some of the quotes in the article indicate some pretty narrow thinking.
First, less light == cooling down? "If that was the case then we'd all be freezing to death."
There isn't less radiation coming from the sun, just less reaching the earth's surface ("there has been a general increase in overall solar radiation over the past 150 years"). This means it's probably being absorbed in the atmosphere, probably being converted to heat. By preventing that sunlight from being converted to non-heat energy (photosynthesis, evaporation), this might be heating up the atmosphere even more. I don't know where this heat goes, but it *might* be possible that less surface light means increased global warming. I guess the real questions regarding surface light and temperature is: How does a decrease in surface light affect the amount of energy that escapes the earth?, and Are we storing energy and remaining cool, or letting more energy be converted to heat?
Second, "I don't think that aerosols by themselves would be able to produce this amount of global dimming." Aerosols "by themselves" might not filter that much light, but pollution does lead to "bigger, longer lasting clouds." It sounds like the "global dimming" just means less direct sunlight, not necessarily dimmer direct sunlight.
Actually, the entire electricity requirements of the United States could be served by wind turbines with a combined land-use footprint of only 14,000 acres, including enough grid redundancy to provide 99.5% uptime through long grid transmission to areas experiencing calm winds. (The remaining 0.5% backup could be hydro or whatever.) That area is only twice the size of the Stanford campus, and as large as the amount of Oak forest that California loses each year.
Some people consider turbines ugly at first glance, but more people want wind turbines in their neighborhood than want mercury-spewing coal smokestacks in their state.
Wind power is the fastest growning renewable industry and is expected to be the dominant form of power production in less than 30 years.
Please see the Windpower FAQ for more information.
It's interesting to note that Earth's closest twin planet in terms of position and size is Venus, where a runaway Greenhouse Effect keeps surface temperatures around Venusian a toasty 480C (894F) but the entire planet is mired in a perpetual twilight gloom (verified by the Russian landers) due to the extraordinarily thick atmosphere (around 9000 kPa or around 90 times Earth's atmospheric pressure). Venus's oceans long ago boiled away in this runaway Greenhouse Effect. The oceanographic runaway Greenhouse Effect begins to occur over large bodies of water at around 27C (80F). Even ignoring current human-directed climate change, the increasing solar output of the Sun as it moves along a typical Main Sequence stellar evolutionary path means that sooner or later the Earth's oceans will also vaporise and temperatures soar quickly to Venusian levels. Strange days indeed lie ahead of us...
Da Blog