Fewer aerosols may step up global warming
Photo by farl
Scientists believe they’ve seen a thinning of the aerosols found in Earth’s atmosphere.
That’s important because aerosols – which come from industrial pollution as well as natural causes – help shield us from the effects of global warming. Some refer to them as a global “sunscreen.” Aerosols cool Earth by reflecting sunlight. So, fewer aerosols mean more warming.
Earth & Sky spoke to Michael Mishchenko at the Goddard Institute of Space Studies in New York. His study shows a decrease in aerosols in the lower atmosphere since 1991.
Michael Mishchenko: All of a sudden we saw a change in the background value, globally by as much as 20 percent. And this is a very significant change.
With fewer aerosols, the effects of global warming will be felt more intensely, according to Mishchenko.
A reason for the decrease may be the steps taken in the 1970s by industrialized nations to curb emissions.
Mishchenko: There are fewer particles to reflect the sunlight and so the global warming produced by the greenhouse gases … may have become more obvious because of this decrease in aerosols.
He also said Earth’s temperature is increasing now at a faster rate than the models predicted some time ago. It could be that those models didn’t take the potential for this aerosol decrease into account.
Our thanks today to NASA: explore, discover, understand.
Referring to national efforts to curb industrial emissions at the end of the 1970s, Mishchenko added, “In this case, we believe that this change in aerosol amount is a man–made change, most likely. Simply because, if you look at what happened to the countries of the former Soviet Union and what is the effect of the Clean Air Acts in the United States and in Europe, this combined effect was to reduce the amount of aerosols.”
He continued, “If you look at what we can do to aerosols on a global basis and what the effect of this change may be, you can start to believe in global warming being the result of human activities.”
Scientists will have more answers when NASA launches an instrument designed to determine the composition of the aerosols – whether they’re natural or manmade – at the end of 2008. It will be part of NASA’s Glory mission.
Global ‘Sunscreen’ Has Likely Thinned, Report NASA Scientists
Our thanks to:
Michael Mishchenko
Senior Scientist
NASA Goddard Institute for Space Studies
We know that industrial pollution contributes to man-made global warming by increasing atmospheric carbon dioxide. Reducing pollution lowers carbon dioxide production and slows down global warming. If at the same time, reducing industrial pollution reduces atmospheric aerosols and increases global warming, then what matters is the relative effect of these opposite influences on global warming Nothing in this article addresses that aspect of the situation. Please follow up on this. It is important, because as reported, your article might be cited support the ridiculous conclusion that increasing industrial atmospheric emissions will lessen global warming. All direct evidence is to the contrary.
Gene,
Thank you for your input, and for raising this point. We’re worried about this too. The aerosol issue is one that’s very complex and not easily explained in a 60 or 90 second spot. Here is a transcription of a part of my interview with Michael Mishchenko:
Michael Mishchenko: We should absolutely cut aerosols. That we have fewer aerosols is good. But the unintended consequence of this is that there are fewer particles to reflect the sunlight and so the global warming produced by the greenhouse gases … may have become more obvious because of this decrease in aerosols. Of course, this means we have to cure the emissions of the greenhouse gases, first of all the carbon dioxide methane contributions.
Lindsay Patterson: So what’s happening is that aerosols have delayed us actually seeing and recognizing global warming.
Michael Mishchenko: Exactly, that’s what we think, yes. That’s what you see if you look at the global temperature record, it’s out of control. When it started to be quite obvious was almost exactly the same time as there were fewer aerosols in the atmosphere… The temperature is growing at a faster rate than the models predicted, and this is because the models didn’t take into account the potential decrease in aerosols population.
I hope this provides some clarification.
we need factories to start belching out more oxygen. more oxygen in an atmosphere allows more of the suns energy to be reflected into space thus less trapped heat.of course the down side is a more flammable atmosphere,but much cooler temperatures even in summer
i am confused. i thought the less particles in the atmosphere the more suns energy was reflected back into space resulting in lower temperatures. and that co emissions were actually particals that trappped heat from the sun resulting in a warming of our atmosphere. could mr mishenko clear this up?
scratch that idea i just visited his site. it made me think up a joke. how many nasa engineers scientists and administrators does it take to screw a bolt?....all of them. it also reminds me of a gary larson cartoon where a bunch of scientists are standing around a rocket that looks like its made of cardboard and duct tape and one says lets face it gentelmen were not rocket scientists. before you get mad at the joke nasa people would love it. because they get it.
today i read some of his work and this is actually good science. although i learned that this is even more complex than i could ever imagine. i found there were heavy carbon isotopes light carbon isotopes and their effects were good and bad depending on the study.if anyone cares to truly learn about this topic simply buy used college text books on metorology,the atmosphere, and the best being,an atlas of life on earth .im very pleased that this blog has me looking things up again, and in real books for that matter. what a thought provoking pursuit.
Several years ago, the learned among us said that all the soot and other particulates in the atmosphere would shade us and kill us. Then, the carbon dioxide from our oil fired economy is going to heat us up (during some of the coldest and snowiest weather in years) and kill us. Now the lack of pollution is going to heighten the effect of the other, more evil, pollution and kill us.
Might it be that there is no truth to any of this? I think that is the case. These so called problems are political and economic, not physical.
Sam, I’m glad to hear that this website has encouraged you to learn more about science. Indeed, this is a very complex issue, and not easily reduced to one problem lessening or heightening the other.
What aerosols in the atmosphere have done is provide us with not only a physical, but also a mental, shield from global warming. According to Mishchenko, the effects of global warming are occurring regardless of aerosols, it’s just that the aerosols have kept us from recognizing it on the surface of the Earth. They’ve given us the luxury of having this debate at this late stage.
thanks to both of you
i work here at the cape and anyone would laugh most especially bruce to learn that things are not as clear as the media makes it out to be. except of course for mathmaticians. at least their field of study can be verified on paper.bruce is closer to the truth by understanding it could be we are in pusuit of a feathered elephant
That story sounds quite contradictory to what the scientist have been telling us in the past. And it seems like the GLOBALISTS and the NEW WORLD ORDER have put out this story to gear us up to accept the next story…“We can intentionaly spray aerosols into the lower atmosphere to reduce global warming”...hence…CHEMTRAILS. Which in effect is also a way to reduce global population. No conspiracy theory, it is a proven fact that chemtrails contain virus’s and other very harmful junk that makes people very sick.
In 1983, Dansgaard & Oeschger were among the first people to examine two ice cores, each approximately one mile long, brought up from the Greenland Ice Sheet. Laborious studies of the cores proved that global warming occurs every 1500 to 2500 years – even during the Ice Ages and interglacial climate swings the 1500-year cycle was superimposed in the core.
The Earth’s elliptical orbit is on a 100,000-year cycle. The axial tilt variation is on a 41,000-year cycle. The “wobble” of the Earth on its axis is on a 23,000-year cycle. But it is the 1,500 year solar-driven cycle that is responsible for our “global warming” – which cannot be prevented. However, history proves that it will bring benefits to man, especially a reduction in famine/hunger, species survival, and a longer worldwide life expectancy.
The “sky is not falling”.
What a bunch of fly in the eye stuff is this. Trees cause could be causing more pollution. I have flown in Alaska for over 12 years and in the winter in the northern most part of the state at about FL350 is a red band of pollution that goes from horizon to horizon and moves daily up higher in latitude or lower, it’s right around the Arctic Circle on the latitude. It’s following the Jet stream. You can not pump 100s of tons of pollution into the air everyday and not expect some day to pay the price. It’s not just us, but we produce a lot for our population %. Our atmosphere, that is the air we breath, is only 2 miles thick. You go above 10,000 feet it gets hard to breath, a pilot can only go for 30 minutes with out supplemental oxygen. 15,000, you will pass out in a few hours, 20,000 you have a few minutes, 30,000 a few seconds. So really were not talking thousands of feet into space. Sort like washing in the toilet after the fact. We need clean energy. Alaska has enough known reserves of Natural Gas to run this country for 150 years. Run the vehicles, produce your electricity, heat your homes, the factories, if any are left. The oil companies , which happens to be British Petroleum is the largest “owner” of the pipeline, refuses to allow the State of Alaska to build the line ourselves. Oil would drop to 10 dollars a barrel. There is no oil shortage now. They have slowed down the amount being pumped out of Alaska because their getting it cheaper in Iraq. This aerosol stuff is because China is going to produce cars, a lot of them and the people who make freon and aerosols would just love to supply that to the 1 billion Chinese who will own a car in the next 10 years. But don’t plant trees because that could be messing up the air. Some said this will extend life??? . Air pollution will extend life. Caution , discuss this with medical help before testing YOUR theory. I invite everyone who believes the gases that cars give off are not harmful, to take your favorite can of aerosol, hook a hose up to your cars tail pipe and put the hose in your car in a locked garage and see how long the aerosol keeps you alive. For those who would do this, do not do this with out speaking to at least 2 Doctors consulting you on why you think you would not die.
It’s simple we have 10,000 feet of clean air, once we fill it with enough toxic junk, we will die. The earth will go on and clean it’s self up. We are a virus and mother nature will just take so much. Be smart. This is serious stuff, you can’t eat more then one fish a week in the most remote places of Eastern Canada because of the mercury that comes out of bleaching the paper white, it comes out the stack and lands in the lakes and streams and the land. We are killing ourselves.
Geoffrey