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Earth

Atmospheric Dust May Have Hidden True Extent of Global Heating (theguardian.com) 115

Posted by BeauHD from the climate-crisis dept.
An anonymous reader quotes a report from The Guardian: Dust that billows up from desert storms and arid landscapes has helped cool the planet for the past several decades, and its presence in the atmosphere may have obscured the true extent of global heating caused by fossil fuel emissions. Atmospheric dust has increased by about 55% since the mid-1800s, an analysis suggests. And that increasing dust may have hidden up to 8% of warming from carbon emissions. The analysis by atmospheric scientists and climate researchers in the US and Europe attempts to tally the varied, complex ways in which dust has affected global climate patterns, concluding that overall, it has worked to somewhat counteract the warming effects of greenhouse gasses. The study, published in Nature Reviews Earth and Environment, warns that current climate models fail to take into account the effect of atmospheric dust.

About 26m tons of dust are suspended in our atmosphere, scientists estimate. Its effects are complicated. Dust, along with synthetic particulate pollution, can cool the planet in several ways. These mineral particles can reflect sunlight away from the Earth and dissipate cirrus clouds high in the atmosphere that warm the planet. Dust that falls into the ocean encourages the growth of phytoplankton -- microscopic plants in the ocean -- that absorb carbon dioxide and produce oxygen. Dust can also have a warming effect in some cases -- darkening snow and ice, and prompting them to absorb more heat. But after they tallied everything up, it seemed clear to researchers that the dust had an overall cooling effect.
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Atmospheric Dust May Have Hidden True Extent of Global Heating More

Atmospheric Dust May Have Hidden True Extent of Global Heating

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  • If only there existed some kind of feedback mechanism where more extreme weather led to more dust in the atmosphere, which leads to less energy reaching the surface. But even if that were the case indirectly, it's nowhere near enough.

  • Hidden seems like the wrong word (Score:4, Insightful)

    by 93 Escort Wagon ( 326346 ) on Wednesday January 18, 2023 @12:07AM (#63218622)

    The dust didn't "hide" anything - the extra heat isn't there.

    The summary uses the word "countered" as well... which seems much more accurate - and less agenda-driven.

    • If the dust is expected to return to the previous levels, then it's accurate to say that it temporarily masked the warming we face. If the phenomenon causing the dust increase were expected to continue indefinitely, then you'd have a point.

      Unfortunately, the article clarifies that the dust levels are falling since the 1980s -- so the use of "hidden" is absolutely correct, since it appears the dust (which was caused partly by human impacts) isn't sticking around.

    • Yes, but saving the world is too important to allow room for people to ask questions. Better they be kept frightened and compliant.

  • Article exaggerates claims of article (Score:3)

    by FuzzMaster ( 596994 ) on Wednesday January 18, 2023 @12:33AM (#63218670)

    The total effect of dust interactions on the global energy budget of Earth — the dust effective radiative effect — is -0.2±0.5W/m^2 (90% confidence interval), suggesting that dust net cools the climate. Global dust mass loading has increased 55±30% since pre-industrial times, driven largely by increases in dust from Asia and North Africa, leading to changes in the energy budget of Earth. Indeed, this increase in dust has produced a global mean effective radiative forcing of -0.07±0.18W/m^2, somewhat counteracting greenhouse warming. Current climate models and climate assessments do not represent the historical increase in dust and thus omit the resulting radiative forcing, biasing climate change projections and assessments of climate sensitivity. Climate model simulations of future changes in dust diverge widely and are very uncertain. Further work is thus needed to constrain the radiative effects of dust on climate and to improve the representation of dust in climate models.

    (I had to edit the quote slightly to make it legible with slashdot's html handling.)

    Both the effective radiative effect and effective radiative forcing could be positive or negative in the 90% range. Only the global dust mass loading has increased since pre-industrial times with 90% confidence.

    I don't doubt that dust could have an effect on the climate, but this paper doesn't provide much insight into its positive or negative overall impact.

  • ...scuff your feet! And not just on Mondays.

  • Dust probably is just one more control loop (Score:4, Insightful)

    by LordHighExecutioner ( 4245243 ) on Wednesday January 18, 2023 @03:27AM (#63218908)
    - Earth warms
    - Wind increases
    - More dust is raised
    - Dust attenuates warming

    There are plenty of these control loops in our ecosystem. No need to worry for this. What we really need is to understand correctly how much of these control loops exist, and how much humans are perturbing them.

  • Sensationalist (Score:4)

    by physicsphairy ( 720718 ) on Wednesday January 18, 2023 @04:32AM (#63218984)

    But after they tallied everything up, it seemed clear to researchers that the dust had an overall cooling effect.

    Is that a fair rewording of the paper?

    In the modern climate, the global mean effective radiative effect of dust, R, is estimated as 0.2±0.5Wm2 (Fig. 3). As such, despite considerable uncertainty in the sign and magnitude of R, which arises from the numerous uncertain and sometimes opposing mechanisms, it is more likely that dust cools the climate than warms the climate.

    Note that the error is twice as large as the effect size and ranges over both positive and negative effects. But the authors are very open that there is an uncertainty issue

    Climate model simulations of future changes in dust diverge widely and are very uncertain. Further work is thus needed to constrain the radiative effects of dust on climate and to improve the representation of dust in climate models.

    Overall, the Guardian write up seems rather sensationalized. The effect could very possibly swing the other way. And when the speculation is "well maybe models didn't account for this" how do you directly attribute that to "fossil fuels" vs other heating factors such as methane, how do you rule out additional unknown factors? I didn't see any claim like that in the actual paper, or in quotes from the author in the write up. Seems like the person who wrote the Guardian article just thought they personally "knew enough" to extend and embolden the conclusions.

  • Global dimming has been known about for ages.

  • ...the smoke from coal generations helps to cool the planet while killing people?

    • Worse, the scrubbers put on the smokestacks to keep the smoke from killing people made global warming worse.

  • Hey, that's a pretty alarmist headline for the following sequence of events:

    Principle Investigator: I propose that atmospheric dust may have an effect on climate. (*does research*) Whoa. Looks like my hypothesis is true.

    Climate Science Academic Community: Our models are incomplete according to this research. We need to adjust them.

    Wow, they found another variable. What exactly is being "hidden?"

    I swear, science press headlines need to die in a fire. Clickbait sucks.

  • Er (Score:4, Interesting)

    by cascadingstylesheet ( 140919 ) on Wednesday January 18, 2023 @07:58AM (#63219230) Journal

    But after they tallied everything up, it seemed clear to researchers that the dust had an overall cooling effect.

    Then how is that "hiding"? It's literally "counteracting".

    It's like saying you "hid" how dirty you are by taking a bath.

  • Anyone else noticed they're consistently finding new things that affect the climate which affect current modelling? One wonders just how worthwhile the models are. What worries me is they're planning on deliberately interfering with the climate based on flawed data with no true idea of just how flawed it is. It is reasonable to think that some of the things they're planning to do may making things worse, not better but the problem is we're likely to not find out for many years after we've started.

    • This is science marching onward. Models just get better and usually more complex.
      Duh, you use the BEST answer you have at the time.

      This is OLD stuff, current modeling factored in global dimming for at least a decade now - particle pollution (cooling) is largely tied to chemical pollution (warming) and as we phase the worse one out the other will at it's own speed go away as well. I would guess particles will leave faster than chemical gasses so if we stop overnight there will be a period of warming that a

  • The entire thing is written as if there is some sort of deception or trickery going on.

    The dust has a cooling effect.

    Shouldn't we be glad it did this? Isn't this exactly the intent of some geo engineering proposals: to loft chemicals or particulates to block solar heating?

    Are those projects being described as projects to "hide" warming?

    • I agree, 100%. Actual WTF.
    • It is indeed good thing.
      Though the problem is this: We are slowly reducing particle emissions (filters and stuff like that), so in time the dust amount goes down.
      And with it, the cooling effect goes down.

      • One might hypothesize that this is really the key cause of the purported recent 'spike' in warming due to CO2.

        If particulates have been a major issue since the start of the industrial revolution, and we relatively recently started doing things that actually reduced them then a gradual multi-century warming trend would instead look like a hockey-stick with 'sudden' recent warming coinciding with the clearing.

    • GLOBAL DIMMING has been around for probably a few decades now.

      At 1st it was controversial as it looked like the deniers may be funding more junk science to tell us smoking is good for your health. It proved to align with global warming science in the end.

      The dimming does help but this particle pollution is largely generated by the SAME warming chemical pollution and it does not just cancel out which is why we still had a huge problem. What it showed:
      1) humans are the cause (already known but in the denial p

  • The effect the dust has is actually part of the total. It's not that it's faking, or masking anything. It's a fully fledged participant in the system, and just because someone forgot to keep it out of their calculations before, doesn't mean it doesn't count. If it moderates the heating, great, count our lucky stars. What's the deal here? Are we only allowed to calculate carbon based on the models, and NOT based on the effect it has on our actual measured temprature?

  • Why is it framed as "hid the true extent of" rather than "has been reducing the severity of". Is the dust variable on of noise or of signal?

  • Once upon a time, the earth was hit by a giant rock. It was so big as to make a shockwave that rippled the entire crust from once end to the other, to the other...The oceans by then filled with new liquid frozen for thousands of years sloshed freely about the coasts of the continents, washing all of humankind's dross into the abyss. When this new creation was complete, there existed a very large number of rock surfaces exposed to the atmosphere. All these fresh surfaces immediately begin reacting carbon out

  • Wait, does global heating cause global warming? Or the other way around? Maybe they mean glow-ball heating? Warming? Frying? Roasting? It's all so confusing. The only certain thing is that the sky is surely falling.

  • I remember in the 70's, they were conserned about a new "ice age" because the smog/pollution was blocking out the sun. Now they are worried about global warming. Then bring back smog & pollution. Boy, you just can satisfy these climate types.
  • Would read the headline and say, wow we really need to reduce emissions even more! I say, why in the world would I ever listen to climate scientists and thier models if they can't account for dust? What else are they missing?

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