What do you guys think about "Global DIMMING"??

Question

I just saw a fascinating show the other day about Global Dimming, the phenomenon that occured when we were pumping "DIRTY" smoke into the air from our powerplants and cars before catalitic converters and cleaners to reduce polution. The effect of this smoke was a COOLING effect, but it also caused acid rain, and serious health problems.

What the show pointed out was that the reason warming has really sped up in the past 30 years is because of all the steps we have taken to clean up air polution. This cleaning does nothing to the CO2 produced, so the warming started.

Couldn't we develop a safe additive for powerplants that has the same dimming effect as the polution from years ago but doesn't cause acid rain and health problems?

Answer 1

What about Global Dumbing? Nevermind big powerplants... our elected Federal government officials are the real culprits.

In particular, Congress.

Answer 2

The idea may be necessary in the future as a last resort if global warming gets into a positive feedback loop. There is no evidence that this measure is needed now. A better approach would be to avoid getting into a positive feedback loop by moderating our emissions of greenhouse gasses. Aerosols have a short lifetime in the atmosphere. The same effect could be achieved with plants. There are many instances of biological colouration achieved by interference. Plants use only a small part of the solar spectrum for photosynthesis and could be engineered to reflect more of the less useful wavelengths in the visible range back into space.

Answer 3

Actually, if you research a little further you will see that these aerosols that caused global dimming concerns are still being generated by the power plants and cars and airplanes.

The same people who made a big deal of global dimming are the same people who make a big deal of global warming.

But the atmospheric scientists often will talk about how they don't know if the net effect of human generated chemicals is a net cooling or warming effect. We simply don;t know which way the balance is.

So if you decide to purposefully add more stuff you could be making global cooling worse!


It is well known that most of the heat that is re-radiated by the earth is already absorbed by the atmsophere (about 95%). Which is why even if we dramaticaly increase the green house gases their is a hard limit to how much extra heat can be trapped.

However, aerosols could potentially decrease the amount of heat getting to the surface much more dramatically. Theoretically, they could stop it all. This is why global dimming is more serious I think. I don't think you want to do it on purpose.

Answer 4

I think it is a crock, the reason for the apparent speed up in warming over the last 30 years, is Agung 1962, 1980 St Helens, 1982 El Chichon and the 1991 Pinatubo eruption. There has not been an eruption that has effected climate in over 16 years. The SO2 emissions from these eruptions damaged ozone and caused more acid rain than any industrialization side effects.

Answer 5

This was an outstanding NOVA episode (see first link below) on PBS this past week. Most PBS stations are airing this again over the coming weekend.

I think the key point we need to take away from this is the amount of particle pollution we have been pumping into the air actually served to temper the impacts of global warming. An odd double edged sword -- man made pollution has both created global warming while also slowing its most damaging aspects.

Mankind's goal is to figure out how to reduce CO2 admissions as efficiently as we've managed to reduce particle pollution -- a much more challenging task, but one I think is achievable.

Growing acceptance and the realization that global warming is happening are the first steps (which I hope we're accepting now). Serious concerted efforts to reverse the effects of global warming by ALL countries is where we need to be headed next.

Answer 6

Well, Nature has experimented with it and proven it works, for up to a year at at a time. Look up "The Year Without a Summer". Mid 1890's, so is reasonably current.

Man has shown it is feasible, but then the Environmentalists put the kibosh on that and "Global Warming" was shown to shoot up very rapidly after the Environmentalists got done. As you correctly noted.

But before then these were pretty much the same folks screaming about we were returning to the ice ages from the "dimming" as holler about the world being destroyed by heat now that it is nice and "bright"!.

I would suggest it would indicate we are barking up the wrong tree, in terms of restricting the development of the under-privileged nations, raping the jungle for Carbon Credits, and trying to force through laws to stop dead a natural cycle, tho we can perhaps do it. But we do not know it all, or what happens if the natural cycles are interrupted. And the CO2 stays in the deep seas indefinitely, for example.

I think it might well be we could powder something like fertilizer, maybe, or something innocuous, and sow it into the very upper atmosphere, where it would stay suspended for a very long time, and so reduce the sun's heat reaching the earth's surface.

Just this does not help the politicians and others take over the earth, nor does it benefit the developed nations only, but helps everybody.

However, you should consider that historically periods of global warming were NOT catastrophic, but made for better times, in terms of more food, less crowding, and the ability to get away from mere subsistence farming to times of advancement in culture.

I question why when History tells us one thing, our leaders want to take us the other way, into poverty, rigid controls, treating different nations differently, maintaining the gap between "haves" and "have nots"...so many of the ills that are more typical of the times of global cooling.

But yeah, why not see if science can make something to be a factor 50 sunscreen for the earth? Then we would not have to worry about especially good times! Just keep on keeping on, keeping the same old problems, and same old political and economic repressions. Until the Malthusian Dilemma solves all our problems for most of us by famine, or disease, or war...and we can start over again! And do it all over again in another 90,000 years or so.

And as a warning, the scientists that were shushed and driven out were the ones who were warning that the computer models were flawed...and THEY turned out to be right! Maybe we ought not to have a "consensus" of scientists, public figures, politicians, rapacious heads of big companies, setting our policies and lifestyles?

Listen to freedom for a change?? Maybe?

I can say as long as all our energies and monies are devoted to enriching a few and giving them power, we will not be able to check global warming or check out Global Dimming, since it would not be in the best interests of the carbon credits industry, or the razing of the jungles for oil palms, or the builders of sea walls, or keeping the underdeveloped nations down, or the GW environmentalists in their fancy homes.

If people are not driven by panic, they can make considered and better decisions! And if science is not squelched by political correctness and innuendos against those who have questions, we can accomplish some good things. In my opinion.

Let's give this old planet, and the GW crews especially, a good dusting and lie back and chill out!!

Answer 7

There are a lot of ideas about how to counteract global warming by reducing solar radiation. I don't think they're good.

Until we messed things up with greenhouse gases the climate was reasonably stable.

Now we're exerting a major force on it, sufficient to cause harm. But we don't know exactly how much things will get out of hand, because of "feedback" mechanisms that we don't fully understand. Like, reflective ice melts, exposes dark ground, warming speeds up.

So to try and unleash a countering force, also huge, to cancel global warming out seems reckless. How can we know we'd get it right?

It seems to me far better that we simply stop messing around with climate and let nature take care of it. The Earth has self regulating mechanisms and can handle itself.

If we don't mess it up, like we're doing now.

Answer 8

Putting extra sulphur into the atmosphere has been proposed but I don't like the idea (it seems it'll cause drought).

If thing get bad enough that we need to reduce the insolation I think we're just going to have to spend the money to put a filter between the Earth and the Sun.

Answer 9

Lol, Sky. That is a good point. The same people extolling Coleman would be saying meteorology is the only profession where you can be wrong 50% of the time and still have a job had he supported climate change theory.

Answer 10

Well isn't this interesting? I follow all of these, and usually they all have the same progression. First, "It isn't happening at all. They made it up, or made arithmetic errors, or something". As that is being debunked, they'll waffle along sideways to "It's happening, but it's natural, don't you know? Happens all the time. People sure don't cause it" as the debunking ensues on that one we move along to "Why sure it's happening, but it's a good thing, don't ya know? Things just get better and better with air pollution. If we pollute enough, we'll reach Nirvana. " So you can always see how long a particular fairy tale has been around by which argument is being used. Since these folks like to recruit, you see people at all stages of evolution, and the level of white noise remains high.

Those are the things I've become used to hearing by the people who want you to believe Global Warming is a hoax, perpetrated by scientists all over the world being showered with money by their various governments. The people behind the whole thing are of course, the commie-pinko-leftist-etc., who upon close scrutiny, invariably can be found to possess horns and a tail.

What is now being called "dimming", on the other hand has been around at least 20 years under different names. The basic idea is that the greenhouse gases (especially the ones containing carbon) rob the incoming light and heat of the sun of some energy, proportional to their concentration in the atmosphere. Because of this, some of it isn't energetic enough to pass through the atmosphere a second time if it's reflected back, as a lot is. So, if you add more of these gases, more heat gets trapped, and the earth gets warmer. That's Global Warming. On the other hand, particulate pollution is a solid, including "black carbon". Light can't pass through it at all. So, if you start adding black carbon to the atmosphere, it acts as a sunshade, proportional to its concentration in the atmosphere. This was the basis of Carl Sagan's "Nuclear Winter" concept. By simple math he showed that even a fraction of the existing nuclear arsenal was more than enough to burn all the earth's cities and forests (that had been known for a long time). The amount of particulate matter that would be released was enough to shade the earth sufficiently that all plant life would die. Those conditions could be expected to prevail at least 2 years. Animal life would also die, simply running out of food. The bulk of the particulate matter would be black carbon. That's Nuclear Winter.

Immediately the contrarians of that day suggested that since the effects of the two were opposite, they would cancel each other out and nuclear war was in no way a bad thing for people and the planet. (Ice Cubes would actually get cheaper!) Carl's answer was that unlike the burning of fossil fuels, the amounts of both types of gaseous carbon released by burning all the cities and forests was, fixed, finite, predictable, and a couple of orders of magnitude less than what would be required to counter the effects of the black carbon particles. There are a couple of other reasons it wouldn't work, but that was sufficient.

Today, we seem to have the same argument used with the opposite set of conditions. It's proposed that if the temperature rises due to the release of gaseous carbon, we can fix it by releasing black carbon, or other solid particulates. In other words, pollution is a good thing, not in any way bad for people or the planet. (less fuel will be reqyuired to prepare fried foods!)

Yes, the earth is "dimming" (meaning that it's albedo, or the amount of reflected light is decreasing). That shows we're still releasing a whale of a lot of soot into the air, but not enough to block the passage of light entirely. As long as some light gets through the earth will continue to get warmer as long as we continue releasing gaseous carbon also. It will still at some point get "too hot" for our species, it will just take longer. ("Prolong the agony", as was once said) If we block all of the incoming light and heat, then it will get cooler, no matter how much gaseous carbon we release. Plants won't be able to grow, so we'll run out of food and die that way too.

What it comes down to is that energy is conserved, so there's no free lunch, no matter how hard we wish for it.

Here is what's interesting to me. I noticed a long time ago that the same people who seemed to like nuclear war also liked pollution. What this "dimming" business tells me is that in both cases something they deny is used to cancel the effects of something that can't be denied.