Global Dimming 637
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."
Re:So instead (Score:5, Insightful)
Agricultural output (Score:2, Insightful)
Comment removed (Score:2, Insightful)
Re:Sunglasses (Score:5, Insightful)
Re:Sunlight (Score:5, Insightful)
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
Kind of emphasizes a major point. (Score:4, Insightful)
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.
Re:How will H usage affect this? (Score:5, Insightful)
Re:yeah right (Score:5, Insightful)
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
Hasn't happened yet (Score:1, Insightful)
It hasn't happened yet. The "man-made global warming" allegations are all politics and are not science, since there is no evidence of human effects and what they are (if there even ARE any). The "global warming" fad IS on its way out: the cooling claims are already starting. They will gain ground when these can be used by someone to blame on political enemies. Just like the global warming claims have been.
The "global cooling" fad of the 1970s too was put forth by ideologically-minded scientists who were so sure that they were right. Just like today's ideologically-minded global warming scientists.
It is all politics. No where is this more apparent than the Kyoto Accords, where the "good" countries are allowed to greatly increase their supposedly global-warming causing pollution while the "bad" countries must damage their economies and cut their emissions. If Kyoto was serious about its environmental claims, it would have demanded reductions on all countries involved.
Re:So instead (Score:4, Insightful)
Not necessarily. Venus, hottest planet in the system, is completely covered in clouds. They act as a blanket to keep heat in (cloudy nights are warmer).
Re:So instead (Score:3, Insightful)
Re:Agricultural output (Score:5, Insightful)
Since those yields are not sustainable, we're headed for trouble with or without global dimming.
Saying industrial agriculture is the solution to feeding our overcrowded planet is rather like saying that getting more credit cards is the solution to personal financial problems.
Re:yeah right (Score:2, Insightful)
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.
Driving a Truck Through This One (Score:5, Insightful)
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).
Re:yeah right (Score:3, Insightful)
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.
Re:The unintended benefits of pollution (Score:5, Insightful)
Re:How will H usage affect this? (Score:2, Insightful)
Re:So instead (Score:2, Insightful)
Que the argument from ignorance fallacies (Score:5, Insightful)
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!"
The price of uncertainty. (Score:5, Insightful)
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 [noaa.gov]. 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.
Re:Kind of emphasizes a major point. (Score:5, Insightful)
From my point of view it is about:
Those seem pretty practical demands to me.
Re:The First Church of Environmentalism (Score:3, Insightful)
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 [web.uvic.ca] (which is now generally called "the scientific method"), and a more detailed article describing the scientific method in some detail [ucr.edu].
Dratted Dubya, it is his fault! (Score:1, Insightful)
Tell me about it. I was happily driving along on a pollution-free highway in my wind-powered automobile when I heard on the radio that Bush had been elected. In a matter of minutes, the police pulled me over and then escorted me to a Ford dealership, where they then forced me to buy something never seen before the year 2000: something called an SUV.
Re:Interesting Statistic (Score:3, Insightful)
I don't believe this statement is factual. Source, please.
C//
Re:Driving a Truck Through This One (Score:1, Insightful)
2. Astronomers have been pissing and moaning about crappy atmospheric effects on their telescopes for decades. When the Hubble was being built and launched, they did say that the problems were getting worse, and that many low-land observatories, which had been serviceable in the 50's, were nearly useless in the 80's and 90's.
3. Well, for one, we do. Places that havn't been above freezing in centuries or more not just getting above freezing, but staying there long enough to melt ice sheets that were once thick enough to support heavy cargo jets landing on them. But that's a different matter alltogether.
This is mainly dealing with visible light, from what the article says, so talking about heat is a moot point. If it were heating the atmosphere, or just being radiated off into space, either way, the point it, it's not reaching the ground. Plants get most of their energy from blue light (between Infrared, ultraviolet, and visible light, blue light is absorbed far more than any other wavelength by chlorophyl. Red light is absorbed somewhat, but it's lower energy and not effective for photosynthesis).
Even that aside, reflection and reemission into space are contributing factors here too.
4. Global cooling was not the dominant paradigm in the 80's. There was belief that we were headed to an ice age for a simple reason: timeframe. Ice ages ran in cylces, and we should be on our down the cooling phase. Evidence that we were breaking the cylce started showing up in the 50's, and was getting to be pretty damning by the 80's. Global cooling was just a nice little trend that petered out because it didn't fit any of the present-day measurements.
Re:Interesting Statistic (Score:2, Insightful)
On the roofs of buildings. Along side roadways. On the Moon.
Also remember that the bigger you make something, the more difficult is to maintain.
That's why you have a distributed system. A snow storm in new york city doesn't cause a traffic jam in seattle.
Old-style environmentalism (Score:5, Insightful)
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]
Re:Interesting Statistic (Score:2, Insightful)
Re:Agricultural output (Score:3, Insightful)
HIV drugs can be used to stave off the disease, but the cost of drugs deplete funds that would ordinarily be spent on fuel and fertilizer.
The loss of strong laborers may tempt families to engage in unsustainable agriculture, as crop cycling and the like is less financially rewarding in the short term.
There may be other negative effects upon agricultural production as well.
Re:Well of course (Score:5, Insightful)
In laboratory animals, chronic consumption of preservatives and free glutamate affects the hypothalamus and causes obesity, among a large number of other problems. The amount of this in our food has skyrocketed enormously over the last 50 years. In certain countries, such as the US, we eat nearly toxic levels of these compounds without taking notice.
Re:Interesting Statistic (Score:3, Insightful)
How else do you think, the following produciton plant is possible. Even if it only gets 10-20% of the energy from the solar panels on the building, it still produces far, far more panels than are installed on the building.
Solarfabrik [solarfabrik.de]
And also see this study [uni-kassel.de].
The energetic amortization for a solar powerplant is 6-7 years!!! And this is a pessimistic study, others even say it is only 3 years.
Re:Interesting Statistic (Score:1, Insightful)
Payback time is on the order of 18 months to five years, depending upon how it is calculated (and that DOES include disposal). Do you really think that a 190 watt panel takes more energy to manufactur than it provides over a 25-30 year lifespan? Don't believe me - check out www.nrel.gov.
Re:Interesting Statistic (Score:1, Insightful)
ARRRRRGGGG! Stop using this phrase. Either say it is the "only" or say it is "one of the few", but it is impossible for anything to be "one of the only"!
Re:How will H usage affect this? (Score:5, Insightful)
Automobiles are one of the more dirty ways of converting fossil fuel energy into usable energy, specifically because really good filters, and very high temperature combustion are not desirable (for both portability and usefulness reasons).
However, if this is done at a plant, these issues go away. The burning process will be much cleaner.
Why less light doesn't mean cooling down. (Score:3, Insightful)
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.
Re:The unintended benefits of pollution (Score:2, Insightful)
(emphasis by me).
That can't happen, if pollution is the cause of global warming.
Is it? I know only two things: a) we are changing the composition of the atmosphere b) the climate is undergoing sudden changes.
Some say that you need to prove a) and b) are related, I think that before going further with a) we should prove they're unrelated.