Polar Bears and Combustion

The biggest danger to polar bears may not be combustion, but incomplete combustion.  Inefficient or incomplete combustion can lead to carbon particles or dense hydrocarbons going up the smokestack (or exhaust pipe).  We commonly call this soot.  It is one reason white marble buildings in cities look so dingy, and it is a pollution problem we have done a lot with in the US but is way down the priority scale in places like China.

It turns out, though, that soot may have more to do with melting ice and rising arctic temperatures than CO2, and this is actually good news:

“Belching from smokestacks, tailpipes and even forest fires, soot—or black carbon—can quickly sully any snow on which it happens to land. In the atmosphere, such aerosols can significantly cool the planet by scattering incoming radiation or helping form clouds that deflect incoming light. But on snow—even at concentrations below five parts per billion—such dark carbon triggers melting, and may be responsible for as much as 94 percent of Arctic warming.

“Impurities cause the snow to darken and absorb more sunlight,” says Charlie Zender, a climate physicist at the University of California, Irvine. “A surprisingly large temperature response is caused by a surprisingly small amount of impurities in snow in polar regions.”

Zender, physicist Mark Flanner and other colleagues built a model to examine how soot impacts temperature in the Arctic and Antarctic regions. Temperatures in the northern polar region have already risen by 1.6 degrees Celsius (2.88 degrees Fahrenheit) since the dawn of the Industrial Revolution. The researchers incorporated information on soot produced by burning fossil fuels, wood and other biofuels, along with that naturally produced by forest fires and then checked their model predictions against global measurements of soot levels in polar snow from Sweden to Alaska to Russia and in Antarctica as well as in nonpolar areas such as the Tibetan Plateau….

Whereas forest fires contribute to the problem—the effect noticeably worsens in years with widespread boreal wildfires—roughly 80 percent of polar soot can be traced to human burning, adding as much as 0.054 watt of energy per square meter of Arctic land, according to the research published this week in the Journal of Geophysical Research. When the snow melts, it exposes dark land below it, further accelerating regional warming. “Black carbon in snow causes about three times the temperature change as carbon dioxide in the atmosphere,” Zender says. “The climate is more responsive to this than [to] anything else we know.”

If correct, this is an incredibly powerful finding, for a couple of reasons.  First, over the last 30 years since we have had good satellite temperature measurements, the vast majority of the warming has been in the Arctic, with temperatures flat to down in the tropics and the Antarctic.  This has never made much sense in the context of greenhouse warming theory (though its proponents have tied themselves into pretzels trying to explain it) since global warming theory (as embodied in the last IPCC report) holds that the largest temperature gains should be in the lower troposphere over the tropics, and offers no reason why the warming in the Artic should be orders of magnitude larger than in the Antarctic. 

But this soot theory turns it all around.  By this theory, the warming of the Arctic partially results from the loss of ice, rather than the other way around.  And no one would deny that the Artic should have much more soot than the Antarctic, since Northern Hemisphere industrial output dwarfs that of the Southern Hemisphere (and most all soot stays in the hemisphere in which it was created).  This would help explain the differential vs the tropics (soot has less effect on warming when it falls on a rain forest than on snow) as well as the differential between Artic and Antarctic.

But the theory is powerful for another reason:  It would be MUCH easier to engage in a global effort to reduce soot substantially.  While CO2 is a necessary bi-product of combustion, soot is not.  Better furnace design and exhaust gas scrubbing, as well as some gasoline reformulations and internal combustion tweaks, would make an enormous dent in soot production, an effort I would gladly support.

Postscript:  You may actually have heard of black carbon in the context of global warming.  Over the last decade, when climate alarmists began running their catastrophic warming models backwards, they found they vastly over-predicted past warming.  To save their models (god forbid anyone would rethink the theory) they cast about for potential man-made cooling effects that might be masking or offsetting man-made warming.  In this context, they settled on sulfur dioxide aerosols and black carbon as cooling agents (which they are, at least to some extent).  Not having a good theory on how much cooling the cause, they could assign arbitrarily large numbers to them, in effect making them the "plug" to get their models to fit history.

With a bit more research, scientists are beginning to admit the cooling effect can’t be that great.  The reason is that unlike CO2, black carbon and aerosols break down and come to earth  (as soot and acid rain) relatively quickly, so that they have only limited, local effects in the areas in which they are produced.  At most, a third of the world’s land area or about 8% of the entire earth’s surface had any kind of concentrations of these in the atmosphere.  To have a cooling effect of .5-1.0C (which is what they needed, at a minimum, to make their models work running backwards) would imply aerosols were cooling these selected areas of effect by 6-12 degrees Celsius, which was totally improbable.  Besides, almost all of these aerosols are in the norther hemisphere, but it has been the southern hemisphere that has been cooler. 

  • Scientist

    global warming theory (as embodied in the last IPCC report) holds that the largest temperature gains should be in the lower troposphere over the tropics, and offers no reason why the warming in the Artic should be orders of magnitude larger than in the Antarctic. – you obviously haven’t read, or at least haven’t understood, any climate science at all. That warming should be most rapid in the Arctic has been known for decades. Only a true idiot or someone deeply dishonest could make such a howler. Which are you?

  • Stevo

    Go on then. Tell us in what chapter and page in the latest IPCC report we can find the reason for the warming in the Arctic being orders of magnitude greater. And while you’re there, why the interior of the Antarctic continent is cooling slightly relative to the oceans around it. The quantified physics, if you would.

    Chapter and page.

  • Leon Brozyna

    Now that’s where the focus of responsible conservation need be — on soot and particulate matter. It is something far easier to quantify, study, and, ultimately, solve and clean up.

  • The cooling effects can’t be all that great because they rain out quickly. This means on the converse side, that the black soot melting effect would end almost immediately after smoke stack scrubbers are installed across the NH. This could be a good bargain especially for any Democratic Senators who are having buyers remorse over the AGW thing.
    They can propose the soot scrubbers, the wishy washy GOPer (thinking McCain here) can agree, and the Arctic will rebound almost immediately. The Dems can claim victory and hold up their badge of ecologic bonifidies for their more hot headed constituency, and the Republicans can wave their bi partisan “we might sit on different sides of the aisle, but we’re all from the same country” slogans for their conservative base.
    Plus, unlike the all out assault on carbon, this just might actually do something positive for the environment.

  • Scientist

    Stevo – are you trying to say that you are not capable of reading the IPCC report yourself? Or that you don’t believe it discusses the different responses to climate forcing in the Arctic and Antarctic?

    Leon Brozyna – the focus of responsible conservation should be on the main cause of the environmental problem you want to solve. Soot is not the main cause of global warming.

  • Stevo

    “are you trying to say that you are not capable of reading the IPCC report yourself?”

    No. I haven’t said that at all. In fact, I’m well aware of what the IPCC report says about it, and that it does in fact allude to a possible reason. But I don’t think you are, and I’m testing my hypothesis.

    I predicted that you wouldn’t be able to give chapter and page, and that instead you would try to divert everyone’s attention from the failure by trying to tell me to do it, claiming that I hadn’t or couldn’t do it, criticising me for not already having done it, saying it was too trivial and well-known a matter to require references, or dodging the fact that it was only the IPCC version being criticised here by citing other non-IPCC references/authorities of questionable relevance as you’ve done in the past.

    So far… hypothesis confirmed. 😀

  • Scientist

    In another thread you said you don’t like to create HTML links because “I’ve no intention of doing his work for him“. Why, then, would you have any expectation that I’ll provide any information that you request in any kind of convenient form? Instead, how about you tell me what you think the IPCC says about it, and why that is not adequate in your view, and I’ll tell you why you’ve yet again not managed to grasp what is being said.

    My hypothesis is that you are scientifically illiterate, and not just that but smugly proud of your ignorance, that you will only ever quote papers that you think support your preconceived views, that you will generally wildly misunderstand and misinterpret those papers anyway, and that you have no capability of learning or understanding anything about the science of climate studies. So far… hypothesis confirmed.

  • Stevo


    Still no chapter and page number, I see.

  • Scientist

    Tell me what you think the IPCC says about it, and why that is not adequate in your view.

  • Stevo

    “Tell me what you think the IPCC says about it, and why that is not adequate in your view.”

    “I predicted that you wouldn’t be able to give chapter and page, and that instead you would try to divert everyone’s attention from the failure by trying to tell me to do it,…”

    The experiment is going very well, don’t you think?

    I didn’t say anything about thinking it was adequate or not adequate. We can start to discuss that (if you like) once we’ve determined whether your challenge was based on any knowledge on your part, or whether it was just a faith-based leap in the dark. Do you actually know and understand the physics, or are you merely parroting the appeals to authority you’ve heard in AGW propaganda? You have challenged a statement that the version of AGW physics based on the latest IPCC report doesn’t offer a reason for the orders-of-magnitude difference between Arctic and Antarctic warming. Chapters and page numbers, please.

  • Scientist

    Your debating style is thoroughly infantile. If you don’t think the discussion of this issue in the IPCC’s latest report is inadequate, why are you even talking about it? If you haven’t read it, you can track it down with google. Put ‘site:ipcc.ch’ in the search box to get only results from the IPCC’s website.

  • Stevo

    Still waiting…

  • Scientist

    Either you think the IPCC has explained it just fine, or you can point out what the IPCC report hasn’t explained properly.

  • Stevo

    Chapters and page numbers, if you please.

  • Mike

    I’ve always been a proponent of reducing pollution. While others around me, including my father, are against pollution control devices on motor vehicles because they “steal power” from the engine, I’ve always supported them.

    Of course, there have been mistakes made in the `70s whereas the EPA mandated pollution control devices without giving enough time for auto makers to properly engineer the controls, thus causing driveability and performance problems. This has left a bitten taste in the mouths of “old timers” who would deactivate controls to regain some of the lost horsepower.

    Of course today, with computer controlled fuel injection, internal combustion engines are far cleaner. I believe that we should continue to control such pollutants as HC, SO2, CO, and NOx. CO2, even if considered a greenhouse gas, is NOT a pollutant. No matter how many times the newspaper calls it a pollutant, it is not.

    At least the website “www.fueleconomy.gov” gets it right. While they push the whole “carbon footprint” concept, at least I can give them points to using the terms “pollutant” and “greenhouse gas” when referring to real pollutants and CO2.

  • I recall hearing about some Soviet research from the 70’s when the ‘new ice age’ was the scare in vogue. The then Soviet Union had (So I am informed) conducted some fairly successful experiments in creating large scale ice melt by covering the ice with soot.

    Seems like these scare stories are like an old suit, they become fashionable again every thirty years or so.

  • Mikey

    Interesting little pissing contest you’ve got going here concerning the statement, “global warming theory (as embodied in the last IPCC report) holds that the largest temperature gains should be in the lower troposphere over the tropics, and offers no reason why the warming in the Artic should be orders of magnitude larger than in the Antarctic.

    I took the guys advice on searching, and yeah the guy who said the IPCC went into that appears to be if not completely correct, the more correct in spirit at least of the two.

    It doesn’t solve anything, but I think I found what he was talking about here (not the most recent IPCC report)…


    “The IPCC, in its Special Report on Regional Impacts of Climate Change (RICC), produced an assessment of the impacts of climate change on the Arctic and the Antarctic (Everett and Fitzharris, 1998). In addition, the impact of climate change on the cryosphere is discussed in the IPCC Second Assessment Report (SAR) (Fitzharris, 1996). The main points arising from the regional assessment were that the Arctic is extremely vulnerable to projected climate change—major physical, ecological, sociological, and economic impacts are expected. Because of a variety of positive feedback mechanisms, the Arctic is likely to respond rapidly and more severely than any other area on Earth, with consequent effects on sea ice, permafrost, and hydrology. On the other hand, the Antarctic would respond relatively slowly to climate change, with much smaller impacts expected by 2100, except in the Antarctic Peninsula.”

    I’m not sure it matters though. The idea soot melts ice still makes sense. The arctic section of that 2001 IPCC report also mentioned how melting ice releases latent heat, which adds support to the comment in the article that goes…

    “By this theory, the warming of the Arctic partially results from the loss of ice, rather than the other way around.”

  • Stevo


    Thanks for helping out. I had asked the question because I wanted to know whether my opponent was simply asserting that of course the IPCC had discussed it, without himself knowing whether it was true or not or what they had said, as a way of scoring a cheap point. If they had, he ‘wins’ the point for no effort. If they haven’t, it’d cost someone a lot of time and effort to prove it – to no profit, since he never acknowledges any fault. I’m not arguing about whether the IPCC has offered an explanation, I’m arguing about whether he knows what it is.

    That said, the section you present doesn’t really help. Firstly, as you note, it isn’t the latest report. Has this science been superseded since? Secondly, most of the paragraph is talking about a report on the greater damage that climate change would do in the Arctic, so the reference is unlikely to help. The only part that comes close to answering the question is “Because of a variety of positive feedback mechanisms,…” which is vague and uninformative in the extreme.

    What are these positive feedbacks? How do they stack up against the negative feedbacks? How do we know that the drivers are positive? (A positive feedback magnifies whatever effect other forcers have, so warming is made warmer and cooling is made cooler. For example, if aerosols caused net cooling in the industrial Northern hemisphere, the positive feedback would magnify the cooling effect.) Why do these positive feedbacks not apply in the Antarctic? Is the effect quantified well enough to explain why the Arctic effect is “orders of magnitude” greater? What are the physical mechanisms involved here? How much confidence is there: to what extent is it a plausible hypothesis, versus solid, established science?

    The extract you quote answers none of these. If that was the best the IPCC reports had to offer, I’d consider the original claim vindicated.

    But as it happens, and as I said above, the latest report does allude to at least one possible reason for the difference. However, it isn’t so easy to find that not knowing of it could be regarded as evidence that “you obviously haven’t read, or at least haven’t understood, any climate science at all.” As demonstrated by the fact that the person who made this statement apparently hasn’t found it either.

    As you say, it doesn’t matter in the slightest. I’m simply entertaining myself here, baiting our resident troll.

  • Scientist

    Stevo, I hope you’re having lots of fun. If this is the best entertainment you can think of for yourself, then that’s a bit tragic really. Do you realise that the IPCC only summarises the state of current research, in a format that is (or aims to be) easily digestible by the interested amateur? If their summaries do not satisfy you, then read the papers they reference.

  • Stevo

    Oh, I am! 🙂 Although it’s not my only source of fun by any means, so you can save your sympathy. Yes, I did realise that actually – although it’s entirely irrelevant to the debate here. It wasn’t the IPCC’s report that failed to satisfy me, but yours.

    Chapters and page numbers…? 🙂

  • Scientist

    Start with WG1, chapter one, page one, and work your way forward from there.

  • Corky Boyd

    I have oftern wondered why the northern hemisphere was warming faster than the southern. Soot may be one of the answers.

    Soot makes sense because it causes snowmelt bringing earlier thaws and lowered albedo. Indeed during the seventies, when the coming ice age was the current theory, there was a great deal of research for using finely powdered coal to do just that. Soviet scientists in particular conducted airdrops on glaciers with positive results.

    China’s massive coal based electrical generation expansion may account for this. While all this may be just be speculation, particulate carbon might well explain much of the NH temp increase.

  • Flowers4Stalin

    It is ridiculous to assume that most of the NH temp increase is due to soot pollution. The Northern Hemisphere always warms and cools faster than the Southern Hemisphere because it has more land. I am not denying the albedo effect, but Arctic soot pollution used to be worse in the 1900s-1950s and was almost intentional in more northern latitudes which would affect ice more. Yet the ice was high and the world cold in the early 1900s and 1950s-1970s.

  • Stevo

    I notice your time intervals left out 1920-1940. Was that deliberate?


    What sort of flowers?