climate change – Page 3

February 3, 2022February 3, 2022

Rapidly growing lakes are changing the drainage of the Tibetan Plateau

MODIS view of the Tibetan Plateau showing numerous lakes

Featured image: MODIS-Aqua image of the Qinghai-Tibet Plateau via NASA Earth Observatory, created by Jesse Allen.

Article: Ongoing drainage reorganization driven by rapid lake growths on the Tibetan Plateau
Authors: Kai Liu, Linghong Ke, Jida Wang, Ling Jiang, Keith S. Richards, Yongwei Sheng, Yunqiang Zhu, Chenyu Fan, Pengfei Zhan, Shuangxiao Luo, Jian Cheng, Tan Chen, Ronghua Ma, Qiuhua Liang, Austin Madson, Chunqiao Song

Whether we recognize it or not, the land surface around us is organized into watersheds or drainage basins–areas that share a common outlet for precipitation. On human timescales, drainage basins are typically fixed, because they are defined by the slopes and contours of topography that change very slowly or very infrequently. In the Tibetan Plateau, however, rapid climate change is altering drainage basins before our eyes. Recently, Liu and colleagues from China, the United States and the United Kingdom used satellite data to identify dramatic changes in drainage basins over a period of only 18 years.

February 2, 2022February 2, 2022

Defining and Contextualising the Anthropocene

Feature Image: Huge amounts of waste symbolise the impact of human activity on the Earth System. Public domain image by Antoine Giret

Paper: The Anthropocene: Comparing Its Meaning in Geology (Chronostratigraphy) with Conceptual Approaches Arising in Other Disciplines

Authors: Jan Zalasiewicz et al.

Journal: Earth’s Future

We are now entering a new geologic time due to the planetary-scale impact of human activity. The Anthropocene is widely accepted as this new epoch, but debate is still ongoing about its scientific basis and when this new epoch began. As so many different disciplines are involved in defining and characterizing the Anthropocene, it has become difficult to properly define. A recent paper by Jan Zalasiewicz and colleagues aims to provide context as the broad subject spills over into other areas of science, art and the humanities. They emphasise that future studies should stick to the original stratigraphic and Earth System Science meaning of the term to avoid confusion around the term.

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.

December 7, 2021December 7, 2021

Carbon to carbonates: capturing CO2 with rocks

Featured image: a field of basalt in Hawai’i Volcanoes National Park (National Park Service, public domain)

Paper: Potential CO2 removal from enhanced weathering by ecosystem respnses to powdered rock
Authors: Daniel S. Goll et al.

In the 2015 Paris Agreement, nations pledged to work toward a common goal of limiting global warming to less than 2°C compared to pre-industrial times. The Agreement doesn’t specify how the signatories should do this, though: levy a carbon tax? Shut down coal-fired power plants? Use a stainless steel straw? According to the best available climate science, we will need to be doing all of the above and then some. In fact, meeting the target of the Paris Agreement will require negative emissions, removing greenhouse gases from the atmosphere via some form of Negative Emissions Technology (NET).

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 19, 2021October 18, 2021

What can a delta’s history tell us about groundwater’s future?

Feature image: Mosiac of the the Ganges Delta in false color created with imagery from the Sentinal 2 satilite. CC-By Annamaria Luongo, via Wikimedia Commons

Article: Linking the Surface and Subsurface in River Deltas—Part 2: Relating Subsurface Geometry to Groundwater Flow Behavior
Authors: Xu, Z., Hariharan, J., Passalacqua, P., Steel, E., Paola, C., & Michael, H. A.

Deltas are striking features on Earth’s surface, where rivers meet large water bodies. Their flow spreads out into many channels, depositing the sediment they have been carrying, potentially since their headwaters. This sediment creates and sustains the delta, which can be hundreds of miles across. Beyond being mesmerizing, deltas are essential to human civilization, past and present. Nearly half a billion people live on deltas around the world, where the deposited sediment hosts some of the most fertile agricultural land available.

October 13, 2021October 26, 2021

ExxonMobil and Climate Change Communications: A Case Study in Propaganda

Feature image from Pixabay

Article: Rhetoric and Frame Analysis of ExxonMobil’s Climate Change Communications

Authors: Geoffrey Supran & Naomi Oreskes

It’s no secret that ExxonMobil is a major architect of the climate crisis. The oil giants have allocated incredible amounts of time and resources to undermining climate science while continuing to pollute the planet. Now, a recent One Earth publication by Geoffrey Supran and Naomi Oreskes unpacks the way Exxon has so successfully spread propaganda while borrowing techniques from another destructive industry: that of tobacco. Exxon and other oil companies (often supported by powerful right-wing think tanks) have embarked on a propaganda campaign that has morphed from outright denial into a campaign aimed at distracting us, dividing political opinion, and convincing us that climate action is hopeless. Supran and Oreskes delve into the evolution of Exxon’s harmful contribution to this narrative.

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?