Dirty Birds Are Refining Climate Models

By Nathaniel Scharping | October 9, 2017 3:26 pm
A comparison of Horned Larks collected inside and outside of industrial areas during the early twentieth century. The specimens on the left were collected in Illinois, inside the U.S. Manufacturing Belt. The specimens on the right were collected along the western coast of North America, away from industry. (Credit: Carl Fuldner and Shane DuBay)

A comparison of Horned Larks collected inside and outside of industrial areas during the early twentieth century. The specimens on the left were collected in Illinois, inside the U.S. Manufacturing Belt. The specimens on the right were collected along the western coast of North America, away from industry. (Credit: Carl Fuldner and Shane DuBay)

Enterprising researchers working at the Field Museum in Chicago dusted off a collection of Horned Larks to get a better look at the dirt trapped in their wings.

That’s because these birds, some more than a century in age, together form a unique, physical record of industrial-era air pollution. Using soot that billowed from smokestacks and onto feathers during the factory boom, two University of Chicago graduate students updated estimates of atmospheric soot levels in the early 20th century, something previously based largely on models.

Time Travel

As far back as the 1930s, scientists and collectors noted something odd — some birds appeared darker then they used to. The culprit was quickly determined to be tiny particles of soot from the soft, bituminous coal that was powering the growing Rust Belt factory boom, and science moved on.

Shane DuBay is an evolutionary biologist and Carl Fuldner studies art history; they were brought together by a grant program that pairs the arts and sciences to promote innovative research. Based on a shared interest in the ways history collections reveal past environments, they stumbled across the museum’s sooty birds and realized that they had hundreds of winged, atmospheric time capsules from the 19th and 20th centuries.

“All living organisms don’t exist within a vacuum, and any species, humans included, you might find in a natural history collection, if it was collected from an environment, that means it was interacting with that environment,” Fuldner says.

They found several species of birds from the Midwest that contained soot particles picked up during their final year or so of life, and which remained embedded in their plumage. The Field Museum contains hundreds of specimens of some bird species, collected as time-series collections. This creates an unbroken record of a species over a span of years — perfect for the kind of work DuBays and Fuldner wanted to do. Crucially, specimens at the museum are painstakingly labeled with dates and location information — sometimes down to the street corner, according to Fuldner

“It gives us an incredible opportunity to basically map the distribution of atmospheric black carbon over space,” DuBay says.

Clouds of Soot

They photographed over a thousand birds of five different species, the main requirement being that they have light-colored breast and belly feathers. Ranking the birds according to reflectance — in other words, how dark they were — gave them a good proxy for levels of soot in the air. They noted peak levels in the early 20th century and a big dip during the Great Depression, when factory production slowed. As soon as WWII broke out, soot levels rose again with wartime industry, and then tapered off afterwards as legislators began demanding pollution reduction. Matching their results to known events gave them confidence that the model worked, and they took it a step further.

Our previous estimates of atmospheric soot levels between 1880 and 1910 are too low, they say, in a paper published Monday in the Proceedings of the National Academy of Sciences. The birds show soot levels to be much higher than thought, important information given that we use historical records of air pollution to inform our current predictions about climate change. Those previous estimates were based on a model that combined coal consumption numbers with information about the relative efficiency of coal burning at a given time. These remain approximations, however. The birds’ plumage is hard evidence.

DuBays and Fuldner were also able to pinpoint locations where soot levels were the highest thanks to bird specimens collected nearby. Joliet, Illinois stood out immediately; looking back through historical records, they found that it was home to the second-largest steel-producing plant in the U.S. at the time. The find serves as further evidence that museum birds are part specimen, part atmospheric measuring device.

Continues Today

The technique is filling in gaps in our historical knowledge, but it could find use even today, in places like Beijing where air pollution continues to be an issue. Though the species may differ, the fact remains that animals there are inextricably linked to their environment and the changes it goes through.

“Time and time again there are examples of the value of historical collections of specimens from the past that help us to address our present-day environmental challenges,” Dubay says.

Collections of bird eggs and raptor observations were crucial to unveiling the harmful effects of DDT in the 1960s, and bird feathers served as an early alarm for elevated levels of mercury in the Atlantic. Who knows what other trends might await discovery still, locked away in museum collections?

“All of these specimens that exist in collections; at the time they were incorporated into the museum, no one could have ever known how we would have used them now to address this question,” Fuldner says. “It’s hard to know how the specimens we collect now are going to be used in the future.

Likewise, the meticulous ornithologists of the 19th century never anticipated this day. They simply trusted in the importance of their work.

CATEGORIZED UNDER: Environment, Living World, top posts
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  • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

    Sooo…Enviro-whiners will now demand we return atmospheric soot content to “normal” levels to combat Global Warming? Turn of the 20th century, the Hudson River froze to ice more than three feet thick. Chilly/

    Did avian feather soot deposits suppress ectoparasites? Birds today add cigarette filters to their nests for nicotine parasite suppression, DOI:10.1111/jav.01324, DOI:10.1038/nature.2012.11952

    • Sven_Golly

      It’s called science Al. People create a hypothesis, test it, and publish their results for other people to examine, duplicate or refute.

      They weren’t studying “ectoparasites”, cigarette butts or the Hudson River because that’s not how science works.

      If you want people to reduce soot levels you will need to prove that there would (or wouldn’t) be a benefit to it because that wasn’t the issue they were studying.

      I look forward to your published study.

      • OWilson

        Thankfully we don’t need to get “peer reviewed” study approved to comment in a “join the discussion” thread!

        All it takes here is a little logic, common sense and (hopefully) a sense of humor! :)

        • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

          Social intent is about ideas not facts because all voices are equal: “My ignorance is better than your knowledge.” By majority vote, there is certainly more of it.

          WHAT DO WE WANT? Evidenced-based science.
          WHEN DO WE WANT IT? After peer review.

          “8^>)

          • OWilson

            Just keep posting the facts, and watch ’em dance! :)

      • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

        It’s called science [sic] Al.” Do you know what a DOI number is? Clearly not.

        They weren’t studying “ectoparasites”, cigarette butts or the Hudson River because that’s not how science works.” giggle There are more than a trillion (with a “t”) cigarette butts in the oceans. Enviro-whiners take a deep puff, exhale, then debate as to their source.

    • Conuly

      The only person I see whining here is you.

      • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

        Pay your Carbon Tax on Everything, everywhere, over all time.

        • Conuly

          See? There you are, whining.

          • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

            Pay my Carbon Tax on Everything, too.

          • Conuly

            Whining in the most tired and repetitive fashion.

    • orwellianfuture

      And what does the study on birds using cigarette butts have to do with industrial soot in bird feathers?

      If you can read research studies like this, I’d assume you’d be intelligent enough to distinguish the difference between birds ability to utilize a resource and birds NOT utilizing an environmental factor?

  • OWilson

    In my industrial home town in the 40s, the sun rarely broke through the smoke, and every building in the city was covered in a thick layer of permanent soot that the rain could not wash away.

    The entire city scape was jet black. You could not brush up against it without it transferring to your clothes.

    Today with the burning of domestic coal banned, and succeeding efforts over the years to sand blast the old brick and stone facades, there is little evidence of those Charles Dickens days. The limestone and brick building now shine. The black poisonous rivers are now run clear and are lined with trees and bushes.

    I still look for it though, and find evidence of it under archways, on old buildings and remember the killing smoke and smog.

    I smile a little when this current generation go beserk about the quality of air, water and constant talk of the planet dying in their own particular lifetime. :)

    • orwellianfuture

      As I pointed out to the other ‘fellow’ above, not all pollution is of the same kind. CO2 is doing damage to our environment and causing problems. And there is the plastic, 91% of all plastic manufactured is still in existence. The rest has been incinerated. That’s a lot of plastic leeching its chemicals.

      Making a claim that some clean up has taken place is better than all clean up still needs to take place is a logic fallacy of argumentation.

      • OWilson

        According to NASA, Scientific American, LiveScience, Nature, and most other expert institutions, Co2 is “Greening the Earth”, “Greening the Deserts”, “Greening Africa”.

        According to the U.N., World Agricultural Production is setting records, your after year, to feed a hungry world.

        Go argue your Orwellian claims with them. :)

        • orwellianfuture

          That is not what they’re talking about. And it is also causing desertification. So… which one would you like to tackle?

        • orwellianfuture

          We could start with the Kerbs cycle and ATP.

  • Crunchy2k

    What amazes me is 1970s-80s soot emission controls were effective. The study says the birds hit their cleanest in the 70s-80s. The bird cannot tell us about other pollutants coming out of the stack. But, we can see the SOx and NOx emission controls are effective by the recovering forests once hit badly by acid rain.

    That leaves the question of why Obama thought he needed to shut the clean-burning coal plants down by excessive regulation. I guess we can only assume it was the Al Gore science he was following. Obviously, Pruitt is right to abandon the Obama era regulations.

    • orwellianfuture

      Carbon particulates are not the only things coming out of coal stacks. CO2 is also being emitted. CO2 is warming the climate. And despite what people think, forests can only uptake so much of any gas before it affects their growth and their ability to produce nutrients. The same goes for fruit and vegetables and the humans and animals that feed off them.

      Obama did not shut down anything with regulation. Coal was on its way out anyway due to economics. Coal was getting too exspensive. With fracking becoming cheaper, it just made monetary sense for companies to go with NG. (Natural gas).

      And Al Gore had nothing to do with the science. It was the Scientists. Al Gore just presented what the scientists had been studying for over 120 years.

      • Crunchy2k

        If you wish to believe CO2 is a pollutant, then you might as well go ahead and declare water a pollutant. Water is a powerful solvent that carries dissolved heavy metals, dissolved gases, fungi, bacteria, viruses, dandruff, etc. and it reaches over 90% in the air around us.

        Obama’s EPA was going to only they were going to use the term PM2.5 particles. They even have a webpage that can scare the bejabbers out of anyone who has never read the biological sciences. The Obama EPA has been working with similar thinking minds in the EU to set PM2.5 particle limits. In other words, every rainy day will become Red Alert pollution day. LOL

        Since the hockey stick graph became a thing and attracted a large romantic following, archeology on Greenland’s lost Viking settlement has progressed. They landed in Greenland during the beginning of the modern warming period in 900AD. It was every bit as hot then as now. The modern warming period didn’t start in the 1700s with industrialization. It started hundreds of years earlier and was paused by a large enough phenomena, it caused what we call the mini ice age during the medieval period. The last recorded Greenland Viking was in 1485.

        • OWilson

          According to The Danish Meteorological Institute, (DMI) Greenland has been recently ADDING net mass to the ice cap and the main two famously “melting” glaciers are growing again.

          • Crunchy2k

            I certainly can see why. Warm water evaporates and falls as snow in cold areas. I was hoping to see the Northwest Passage open in my lifetime, though.

        • orwellianfuture

          I never said CO2 was a pollutant, although it can be. It is a greenhouse gas. There are only two atmospheric gases that are NOT classified as trace gases. Do you know what they are? Of course water vapor makes up most of the atmosphere, duh. And not one climatologist would say otherwise. And water vapor is about 75%.

          Now, if you wish to throw around Debunked claims of Medieval Warming Periods, because they only occurred in Europe and not globally, and stick to the actual science, fine but I won’t partake in the same regurgitated ‘hypothesis’ of deniers that have been debunked, repeatedly.

          • Crunchy2k

            If you are interested in that time period, may I suggest the Angkor Wat dig in Cambodia. It rose is 1100AD only to be abandoned by the 1400s. The archeology is far from finished, but there is evidence of dramatic weather events there.

    • jug

      Obama was out to put this country on the skids, any way hr could.

      Communist all his life, hell, his whole family was! And I mean “his real father”!
      Who was a card carrying member of the Communist Party of the USA!
      (CPUSA!)

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