Climate Change – Geobites

March 13, 2023March 13, 2023

Eunice Foote, the original founder of climate change dynamics

Featured Image: Artist rendition of Eunice Foote conducting research on compressed gasses. Image courtesy Carlyn Iverson, NOAA. Featured image courtesy GNU Free Documentation License

Papers: Circumstances affecting the heat of the Sun’s rays; Understanding Eunice Foote’s 1856 experiments: heat absorption by atmospheric gases

Authors: Eunice Foote; Joseph Ortiz and Ronald Jackson

“An atmosphere of [carbon dioxide] would give our Earth a high temperature.”

These words were spoken out loud in August of 1856 at the 10^th annual meeting of AAAS, though not by their author. The speaker continues on to suggest that, “[if] at one period of its history the air had mixed with [carbon dioxide] a larger proportion than at present, an increased temperature…must have necessarily resulted.” This paper was the first recorded finding of the link between carbon dioxide and global warming, and was discovered by the female physicist and scientist, Eunice Foote. While these findings were remarkable on their own, she synthesized the implications to correctly state that carbon dioxide concentrations in the atmosphere both increase global warming and can explain Earth’s geologic history, specifically regarding the Devonian period^1,2. Despite being on the sidelines of science at the time because of her gender, Eunice Foote provided fundamental and groundbreaking knowledge in the field of gaseous physics.

November 15, 2022November 15, 2022

Forests under (mega)fire in the Pacific Northwest

Accompaniment to the Third Pod from the Sun Episode

Featured Image: “Forests under fire” original artwork by Jace Steiner. Used with permission.

Paper: Cascadia Burning: The historic, but not historically unprecedented, 2020 wildfires in the Pacific Northwest, USA

Authors: Matthew Reilly, Aaron Zuspan, Joshua Halofsky, Crystal Raymond, Andy McEvoy, Alex Dye, Daniel Donato, John Kim, Brian Potter, Nathan Walker, Raymond Davis, Christopher Dunn, David Bell, Matthew Gregory, James Johnston, Brian Harvey, Jessica Halofsky, Becky Kerns

The natural legacy of fire in the Pacific Northwest (PNW) is complex. The variable geography of the wet, westside temperate rain forests, to the dry, high elevation forests beyond the Cascade crest make it difficult to find a “catch-all” description of PNW forest fires. For instance, drier forests of ponderosa pines in eastern Washington experience more frequent, low-severity fires while the temperate rain forests of western Oregon rarely see fires. However, scientists can reconstruct historical fire regimes and identify centuries-long patterns of burning related to precipitation, temperature, and ignition frequency to define what are historical patterns and what is modern climate change. In 2020, multiple megafires (a wildfire that burnt more than 100,000 acres of land) broke out in the typically wet parts of Oregon and Washington, burning more than 700,000 acres combined. This event is called the 2020 Labor Day Fires, and Matthew Reilly and colleagues have revealed these fires were likely part of historical regimes and not a product of accelerated climate change.

September 2, 2022September 2, 2022

We’re Here Because We’re Here Because… of Chance?

A painting of many stars as in a night sky, surrounded by planets, with their orbits drawn out.

Featured image: An artist’s depiction of many, many possible planets. This image was created by the European Southern Observatory (ESO).

Paper: Tyrrell, T. Chance played a role in determining whether Earth stayed habitable. Commun Earth Environ 1, 61 (2020). https://doi.org/10.1038/s43247-020-00057-8

Have you ever stayed up at night and wondered, why am I here? Or, more broadly, why are we here, including all living things on this Earth? Don’t worry, you’re not alone, and scientists like Professor Toby Tyrrell of the University of Southampton (UK) have been trying to answer these questions using the scientific method.

His conclusion? It may have just been the luck of the draw. After all, if we weren’t here in the first place, we couldn’t wonder why we were. (Scientists call this the weak anthropic principle.)

Climate scientists often describe their models as alternate (climate) histories. Tyrrell’s 2020 paper takes this idea to its ultimate conclusion, running 100 alternate climate histories on 100,000 randomly generated planets within the habitable zone of their randomly generated stars for 3 billion years. The question he’s trying to help answer is this: how likely was it that the Earth’s climate stayed habitable for the 4 billion years between the evolution of the first prokaryotic cells and us? Was it due to some intrinsic properties of planet Earth, or of life, or was it merely chance?

April 27, 2022April 27, 2022

Methanotrophs: Nature’s catalytic converters

Featured image: A car exhaust pipe, by Matt Boitor on Unsplash.

Paper: Microbial methane oxidation efficiency and robustness during lake overturn

Authors: M. Zimmerman, M. Mayr, H. Bürgmann, W. Eugster, T. Steinsberger, B. Wehrli, A. Brand, D. Bouffard

If you own a car, you’re likely aware that your engine emits greenhouse gases to the atmosphere. Although we usually think of cars and other human activities as the primary source of such greenhouse gases, living ecosystems can also produce these gases through natural processes. For example, lakes are an important global source of methane, a potent greenhouse gas produced in lake sediments as organic matter decomposes. In their recent paper, Zimmerman and colleagues focus on a small but mighty team of microbes that work hard to limit the amount of methane emitted from lakes.

January 27, 2022January 27, 2022

The surprising effects rivers have on our atmosphere

Featured Image: Rio Bermejo meeting up with the Paraguay River, on the boarder of Formosa and Chaco Provinces. Image by Mapio. Used with permision.

Paper: Fluvial organic carbon cycling regulated by sediment transit time and mineral protection

Authors: Marisa Repasch, Joel S. Scheingross, Niels Hovius, Maarten Lupker, Hella Wittmann, Negar Haghipour, Darren R. Gröcke, Oscar Orfeo, Timothy I. Eglinton, and Dirk Sachse

In our current era of rapid climate change, it is critical we understand how every aspect of the Earth system affects carbon cycling. New work by Marisa Repasch and colleagues shows that rivers, under the right conditions, might be able to sequester more carbon in the sediments than released into the atmosphere. However, these findings may reveal how human impacts to rivers will likely increase the amount of carbon released to the atmosphere.

December 14, 2021December 14, 2021

Metal-Eating Microbes Who Breathe Methane

Featured Image: Murky pond in Alaska with “rusty” iron-filled sediments. Image courtesy Jessica Buser. Used with permission.

Paper: Sulfate- and iron-dependent anaerobic methane oxidation occurring side-by-side in freshwater lake sediment

Authors: Alina Mostovaya, Michael Wind-Hansen, Paul Rousteau, Laura A. Bristow, Bo Thamdrup

The table has been set and the food is all prepared. But this is no ordinary dinner party, it’s a microbe party! The guests sit down and proceed to dig into the main course; sulfur, rusty iron, and methane. Curiously, the guests are feeding each other, not themselves! This image seems pretty weird to us humans, but it’s a delight to these microbes. This collaborative method of eating occurs in pond and lake mud all around the world. In a new study, Mostovaya and colleagues describe one such feast in Danish Lake Ørn, that is not only collaborative but may mitigate climate change.

November 16, 2021November 16, 2021

Highway Maintenance “Drives” Carbon Release in Forests

Featured Image: Forest and highway between Trójmiasto and Gdynia, Northern Poland. Image courtesy Robin Hammam.

Paper: The proximity of a highway increases CO₂ respiration in forest soil and decreases the stability of soil organic matter

Authors: Dawid Kupka, Mateusz Kania, Piotr Gruba

There has been a lot of talk about transportation as of late with America’s “Build Back Better Act”. While these political decisions are partially informed by scientific research around climate change, particularly in the United States (where 30% of greenhouse gas emissions result from transportation by road, rail, and air each year), the negative impacts of transportation infrastructure on the climate and local ecosystems are often lost in political discussions. In a new study in Scientific Reports, Kupka and colleagues discuss the broader impacts of highway maintenance on nearby forest soil ecosystems, finding that roadways themselves can increase carbon dioxide emissions by disrupting local carbon cycles.

November 4, 2021November 16, 2021

The Charney Report vs IPCC6: What’s changed in climate science in the last 40 years?

NASA satellite image of Earth from space, showing California wildfire smoke visible in the atmosphere.

Papers: Carbon Dioxide and Climate, a Scientific Assessment by Charney et. al (1979);
Climate Change 2021: The Physical Science Basis by the IPCC (2021)

Right now in Glasgow, Scotland, representatives of world governments and other parties are currently gathering yet again to negotiate political solutions to climate change at COP26. This is the 26th semi-annual Conference of the Parties on climate change, but the history of our understanding of the problem — and attempts to deal with it — goes back even further than that. Speaking strictly of the science of global warming and its effects, what do we know now that the participants of the first COP did not?

October 12, 2021October 12, 2021

Ancient trees tell the story of modern climate change

Featured Image: Larch trees. Image courtesy North Cascades National Park, used with permission.

Paper: Spring arctic oscillation as a trigger of summer drought in Siberian subarctic over the past 1494 years

Authors: Olga V. Churakova Sidorova, Rolf T. W. Siegwolf, Marina V. Fonti, Eugene A. Vaganov, Matthias Saurer

Seemingly straight out of a fairytale, ancient trees are able to convey details about Earth’s complex history to the scientists willing and able to listen. Deep in the Siberian Arctic lie the secrets of past weather events, ocean currents, and droughts that occurred thousands of years ago, locked away in petrified wood and in the oldest living larch trees. We often hear in the news how the Siberian forest is victim to extreme drought and fire—something that is new as of the recent century. But how “new” are these events, and what exactly is perpetuating this new cycle?