Climate change affects greenhouse gas emissions from stream networks

Photo Credit: Mitchell Kmetz

Natural greenhouse gas emissions from streams and lakes are strongly linked to water discharge and temperature according to a new study led by Linköping University, Sweden. This knowledge is necessary to assess how man-made climate change is altering greenhouse emissions from natural landscapes and has large implications for climate change mitigation measures.

“The study is a big step forward towards increased understanding of the greenhouse gas fluxes in stream networks, providing potential to predict future fluxes", says David Bastviken, professor at Thematic Studies Environmental Change. Charlotte Perhammar

“The use of agriculture and forestry as carbon sinks is debated at the moment and the question is how effective such carbon sinks are for mitigating climate change. Our new study shows that with increased precipitation, a larger amount of carbon may be washed into streams and lakes and an increased share of this carbon also ends up in the atmosphere. Hence, landscape carbon sinks may become less effective in the future,” says David Bastviken, professor at the Department of Thematic Studies Environmental Change at Linköping University.

Why natural gas is not a bridge technology

The expansion of the natural gas infrastructure poses a risk to the energy transition, since natural gas is not a bridge technology towards a 100 percent renewable energy system within the meaning of the Paris climate agreement. This is the result of a study by an interdisciplinary German research team. July 2022 in the journal Nature Energy. The researchers examine the natural gas question from five perspectives and provide the gas with a similarly poor climate balance sheet as coal or oil. They recommend politics and science to revise the current assumptions about natural gas.

The study was led by Prof. Dr. Claudia Kemfert from the German Institute for Economic Research (DIW) and the Leuphana University of Lüneburg in collaboration with Franziska Hoffart from the Ruhr University Bochum, Fabian Präger from the Technical University of Berlin and Isabell Braunger and Hanna Brauers from the European University Flensburg.

Energy crisis is only one side of the problem

In the wake of the Russian war of aggression, the government in Germany faces the challenge of reducing Russia's energy dependency and continuing to ensure an affordable and secure energy supply that is in line with climate targets. Efforts are currently underway to balance Russian natural gas, the delivery of which is throttled and unsafe, by building new gas trading relationships and new infrastructure. Claudia Kemfert, head of the study, explains: “Fossil natural gas is neither clean nor safe. The too long adherence to fossil natural gas has led Germany into an energy crisis, from which now only decisive action for consistent decarbonization can lead to a full supply of renewable energies”.

What Is: A Greenhouse Gas

Image Credit: Skeptical Science
(CC BY 4.0)

A greenhouse gas (GHG) is a constituent of the atmosphere that absorbs and emits longwave radiation, impeding the flow of heat from the Earth's surface into space. This process is the physical basis of the greenhouse effect, formally defined as "the infrared radiative effect of all infrared absorbing constituents in the atmosphere," which includes greenhouse gases, clouds, and some aerosols.

It is essential to distinguish between two distinct phenomena:

The Natural Greenhouse Effect: This is the baseline, life-sustaining process. Greenhouse gases, particularly water vapor and carbon dioxide, are a crucial component of the climate system. Without this natural insulating layer, the heat emitted by the Earth would "simply pass outwards... into space," and the planet's average temperature would be an uninhabitable -20°C.

The Enhanced Greenhouse Effect: This refers to the anthropogenic, or human-caused, intensification of the natural effect. The accumulation of greenhouse gases in the atmosphere, primarily from the burning of fossil fuels and other industrial and agricultural activities, is trapping additional heat, driving the rapid warming of the planet's surface and lower atmosphere.

The term "greenhouse" is a persistent and somewhat misleading analogy. A physical greenhouse primarily works by a mechanical process: its glass walls stop convection, preventing the warm air inside from rising and mixing with the colder air outside. The Earth's greenhouse effect is not a physical barrier; it is a radiative one. Greenhouse gases do not trap air. Instead, they absorb outgoing thermal radiation and re-radiate a portion of it back toward the surface, slowing the planet's ability to cool itself. This radiative mechanism, not a convective one, is how a relatively tiny fraction of the atmosphere can have a planet-altering effect.

Study finds large new source of greenhouse gas emissions

An international team has discovered hundreds of large bursts of methane from oil and gas production activities across the globe. The bursts account for 10% of global oil and gas methane emissions and are missing from most greenhouse gas emissions inventories.

Carbon Mapper, a nonprofit organization that partners with the University of Arizona to mitigate methane and carbon emissions and accelerate climate conservation, contributed to the study, which is published in the journal Science.

The team performed a systematic analysis of thousands of images produced daily by the European Space Agency satellite mission Sentinel-5P to estimate the amount of methane released into the atmosphere by oil and gas production activities.

Over a two-year period, they detected 1,200 "ultra-emitters" attributed to oil and gas facilities and long major transmission pipelines that sporadically release greater than 25 tons of methane per hour over most of the largest oil and gas basins worldwide.

Together, these facilities represent more than 50% of the total onshore natural gas production. Most of these ultra-emitters were short-lived, and many are likely due to planned maintenance activities.

The study revealed that in total, these unreported ultra-emitters contribute to approximately 10% of all methane emissions from the oil and gas sector across the six major oil and gas producing countries – an incredibly large contribution for such a limited number of events.

Tropical rivers emit less greenhouse gases than previously thought

Lowland tropical rivers emit large quantities of greenhouse gases, with rates influenced by seasonal flooding.
Photo Credit: Jenny Davis

Tropical inland waters don’t produce as many greenhouse gas emissions as previously estimated, according to the results of an international study, led by Charles Darwin University and involving researchers from Umeå University.

The study, published in Nature Water, aimed to better understand greenhouse gas emissions in tropical rivers, lakes and reservoirs by collating the growing amount of observations from across the world’s tropics – including many systems that were previously less represented in global datasets.

Researchers from Umeå University played a key role in the work, estimating the surface area of rivers and contributing to the data analysis that underpins the study’s findings.

Greenhouse gas emissions in Global South countries linked with IMF lending policies

New research by sociology professor Matthew Soener links loans from the International Monetary Fund to increased greenhouse gas emissions in Global South countries within several years. 
Photo Credit: Fred Zwicky

Greenhouse gas emissions significantly increase in countries in the Global South within a few years after initially borrowing from the International Monetary Fund using structural loans, but not when more flexible lending conditions are involved. 

However, with countries’ second or subsequent IMF loans, their emissions spike almost immediately, regardless of the lending conditions involved, a recent study suggests.

Structural loans, one of IMF’s two primary lending instruments, specify the precise changes borrowers are required to make to obtain the funds. By contrast, quantitative loans require that borrowers achieve quantifiable benchmarks – such as reducing their deficit by 5%, for example – but give them autonomy in deciding how they accomplish it, said study author Matthew Soener, a professor of sociology at the University of Illinois Urbana-Champaign.

Structural conditions impose coercive market constraints, reforms that pressure borrowers to increase their exports, indirectly raising countries’ greenhouse gas emissions through greater agricultural or manufacturing activities, Soener said.

“As a way to maintain growth and repay that loan, countries might decide, ‘Well, we can export more bananas, forest products or other agricultural products’ – or whatever specialty they might have,” he said. “In doing that, the country might be solving one problem, but they are causing another by increasing their greenhouse gas emissions.” 

Methane from manholes and historic landfills: significant sources of gas go unrecognized

Montreal’s municipal greenhouse gas inventory presents an incomplete picture of methane emissions
Photo Credit: Mohammad Rezaie

Cities are responsible for almost 1/5th of the global methane emissions caused by human activities. But most cities don’t capture information about the full range of sources of this powerful greenhouse gas. In 2020, a team led by McGill University, measured methane emissions from various sources across the city of Montreal. The researchers found that two of the four most important sources of methane emissions in the city (historic landfills and manholes) are not included in the city’s municipal greenhouse gas inventories, making it difficult to tackle the problem fully, or reach the city’s goal of being carbon neutral by 2050.

The study provides the first set of direct measurements of methane emissions in Montreal and in the province of Quebec.

The study provides detailed and specific measurements of methane emissions by source – such as the type of manhole or the type of natural gas infrastructure. The results, which highlight the importance of gathering information about the specific sources of methane emissions to set in place mitigation strategies that are adapted to each specific situation should be of interest not only to researchers across Canada and around the world but also to policy makers.

Biodegradable medical gowns may add to greenhouse gas

Photo Credit: National Cancer Institute

The use of disposable plasticized medical gowns – both conventional and biodegradable – has surged since the onset of the COVID-19 pandemic. Landfills now brim with them.

Because the biodegradable version decomposes faster than conventional gowns, popular wisdom held that it offers a greener option by less space use and chronic emissions in landfills.

That wisdom may be wrong.

Biodegradable medical gowns actually introduce harsh greenhouse gas discharge problems, according to new research published Dec. 20 in the Journal of Cleaner Production.

“There’s no magic bullet to this problem,” said Fengqi You, the Roxanne E. and Michael J. Zak Professor in Energy Systems Engineering, in the Smith School of Chemical and Biomolecular Engineering.

“Plasticized conventional medical gowns take many years to break down and the biodegradable gowns degrade much faster, but they produce gas emissions faster like added methane and carbon dioxide than regular ones in a landfill,” said You, who is a senior faculty fellow in the Cornell Atkinson Center for Sustainability. “Maybe the conventional gowns is not so bad.”

Air Pollution Hides Increases in Rainfall

Humans have an impact on rainfall through both air pollution and greenhouse gas emissions.
Photo Credit: Patrick Hendry

We know that greenhouse gas emissions like carbon dioxide should increase rainfall. The emissions heat the atmosphere, causing a one-two punch: warmer oceans make it easier for water to evaporate, and warmer air can hold more water vapor, meaning more moisture is available to fall as rain. But for much of the 20th century, that increase in precipitation didn’t clearly show up in the data.

A new study led by researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) finds that the expected increase in rain has been largely offset by the drying effect of aerosols – emissions like sulfur dioxide that are produced by burning fossil fuels, and commonly thought of as air pollution or smog. The research is published today in the journal Nature Communications.

“This is the first time that we can really understand what’s causing extreme rainfall to change within the continental U.S.,” said Mark Risser, a research scientist at Berkeley Lab and one of the lead authors for the study. He noted that until the 1970s, the expected increases to extreme rainfall were offset by aerosols. But the Clean Air Act caused a drastic reduction in air pollution in the United States. “The aerosol masking was turned off quite suddenly. That means rainfall might ramp up much more quickly than we would have otherwise predicted.”

Unchecked global emissions on track to initiate mass extinction of marine life

Princeton University researchers report that unless greenhouse gas emissions are curbed, marine biodiversity could be on track to plummet to levels not seen since the extinction of the dinosaurs. The study authors modeled future marine biodiversity under projected climate scenarios and found that species such as dolphinfish (shown) would be imperiled as warming oceans decrease the ocean’s oxygen supply while increasing marine life’s metabolic demand for it. 
Credit: Evan Davis

As greenhouse gas emissions continue to warm the world’s oceans, marine biodiversity could be on track to plummet within the next few centuries to levels not seen since the extinction of the dinosaurs, according to a recent study in the journal Science by Princeton University researchers.

Princeton University researchers report that unless greenhouse gas emissions are curbed, marine biodiversity could be on track to plummet to levels not seen since the extinction of the dinosaurs. The study authors modeled future marine biodiversity under projected climate scenarios and found that species such as dolphinfish (shown) would be imperiled as warming oceans decrease the ocean’s oxygen supply while increasing marine life’s metabolic demand for it.

The paper’s authors modeled future marine biodiversity under different projected climate scenarios. They found that if emissions are not curbed, species losses from warming and oxygen depletion alone could come to mirror the substantial impact humans already have on marine biodiversity by around 2100. Tropical waters would experience the greatest loss of biodiversity, while polar species are at the highest risk of extinction, the authors reported.

Greenhouse gas emissions at ‘an all-time high’, warn scientists

Photo Credit: Chris LeBoutillier

Human-caused global warming has continued to increase at an “unprecedented rate” since the last major assessment of the climate system published two years ago, say 50 leading scientists.

The research, published in the journal Earth System Science Data, found that human-induced warming averaged 1.14°C over the last decade and a record level of greenhouse gases is being emitted each year, equivalent to 54 billion tons of carbon dioxide. The remaining carbon budget - how much carbon dioxide can be emitted to have a better than 50% chance of holding global warming to 1.5°C - has halved over three years  

One of the researchers said the study was a “timely wake-up call” that the pace and scale of climate action has been insufficient, and it comes as climate experts meet in Bonn to prepare the ground for the major COP28 climate conference in the UAE in December, which will include a stock take of progress towards keeping global warming to 1.5°C by 2050.   

Given the speed at which the global climate system is changing, the scientists argue that policymakers, climate negotiators and civil society groups need to have access to up-to-date and robust scientific evidence on which to base decisions.

Researchers invent "Methane Cleaner": could become a permanent fixture in cattle and pig barns

A look inside the MEPS reactor (Methane Eradication Photochemical System), where chlorine atoms are formed by UV light and react with methane gas.
Photo Credit: Morten Krogsbøll.

In a spectacular new study, researchers from the University of Copenhagen have used light and chlorine to eradicate low-concentration methane from air. The result gets us closer to being able to remove greenhouse gases from livestock housing, biogas production plants and wastewater treatment plants to benefit the climate. The research has just been published in the journal Environmental Research Letters. 

The Intergovernmental Panel on Climate Change (IPCC) has determined that reducing methane gas emissions will immediately reduce the rise in global temperatures. The gas is up to 85 times more potent of a greenhouse gas than CO2, and more than half of it is emitted by human sources, with cattle and fossil fuel production accounting for the largest share.

A unique new method developed by a research team at the University of Copenhagen’s Department of Chemistry and spin-out company Ambient Carbon has succeeded in removing methane from the air.

"A large part of our methane emissions comes from millions of low-concentration point sources like cattle and pig barns. In practice, methane from these sources has been impossible to concentrate into higher levels or remove. But our new result proves that it is possible using the reaction chamber that we’ve have built," says Matthew Stanley Johnson, the UCPH atmospheric chemistry professor who led the study.

Earlier, Johnson presented the research results at COP 28 in Dubai via an online connection and in Washington D.C. at the National Academy of Sciences, which advises the US government on science and technology.

The inequalities of low-carbon electricity

UNIGE researchers evaluated the consequences of 248 decarbonization scenarios on 296 European regions.
Photo Credit: Rob Martin

Greenhouse gas reduction, new jobs, new investment opportunities: the benefits of decarbonizing the electricity sector - one of the most polluting - are obvious. However, a transition to lower-carbon electricity production could have a negative impact on some regions, depending on their vulnerabilities and their capacity to adapt, while it could have a positive impact on others. A team from the University of Geneva (UNIGE) has precisely mapped the socio-economic consequences of electricity decarbonization for 296 regions in Europe by 2050. It shows that the southern and south-eastern regions of the continent could be the most vulnerable. These results can be found in Nature Communications.

The electricity consumed in Europe is largely produced by highly polluting fossil fuel power plants (coal, gas). This sector alone is responsible for a quarter of the continent’s greenhouse gas (GHG) emissions. Decarbonizing electricity has therefore become a priority. It is also a prerequisite for the decarbonization of other sectors that need to be electrified, such as heating and transport.

The benefits of such a transition are obvious (reduced air pollution, new employment opportunities). However, the process could also maintain or lead to some new inequalities between regions. For example, an area with a coal-fired power plant will lose many jobs and tax revenues if the plant closes. It will be doubly penalized if there is little land available to build new renewable energy plants.

Flaring allows more methane into the atmosphere than we thought

Multiple flares observed in operation in the Bakken Formation in the Williston Basin in North Dakota, 2021.
Image credit: Alan Gorchov Negron, University of Michigan and Yulia Chen of Stanford University

Oil and gas producers rely on flaring to limit the venting of natural gas from their facilities, but new research led by the University of Michigan shows that in the real world, this practice is far less effective than estimated—releasing five times more methane in the U.S. than previously thought.

Methane is known to be a powerful greenhouse gas, but burning it off at oil and gas wells was believed to effectively keep it from escaping into the atmosphere.

Unfortunately, data published in the journal Science shows we overestimate flaring’s effectiveness and, as a result, underestimate its contribution to methane emissions and climate change. But if we fix flaring issues, the payoff is huge: the equivalent of removing 3 million cars from the roads.

Industry and regulators operate under the assumption flares are constantly lit and that they burn off 98% of methane when in operation. Data taken via aerial surveys in the three U.S. geographical basins, which are home to more than 80% of U.S. flaring operations, shows both assumptions are incorrect. Flares were found to be unlit approximately 3%-5% of the time and, even when lit, they were found operating at low efficiency. Combined, those factors lead to an average effective flaring efficiency rate of only 91%.

Burping bacteria: Identifying Arctic microbes that produce greenhouse gases

Sandia National Laboratories technologist Jenna Schambach working with a sample of Alaska lakebed soil. By studying the microbes in the soil, and the gases they emit, Schambach and project lead Chuck Smallwood hope to improve our understanding of the rapidly melting Arctic permafrost and improve computer models of climate change.
Photo credit: Craig Fritz

As greenhouse gases bubble up across the rapidly thawing Arctic, Sandia National Laboratories researchers are trying to identify other trace gases from soil microbes that could shed some light on what is occurring biologically in melting permafrost in the Arctic.

Sandia bioengineer Chuck Smallwood and his team recently spent five days collecting lakebed soil and gas samples. They were joined by international collaborators led by professor Katey Walter Anthony from the University of Alaska, Fairbanks, including researchers from the University of Colorado Boulder, University of Quebec in Rimouski and Ben-Gurion University of the Negev in Israel.

“The Arctic is rapidly changing, releasing large amounts of greenhouse gases; we just don’t know how much greenhouse gases are released every year,” Smallwood said. “Our work at Sandia seeks to improve our understanding of how much greenhouse gases soil microbes are producing, without going out and destructively sampling permafrost soils. The goal is to use sensitive gas detection devices to sample microbial volatile compounds coming out with the methane and CO2 gases instead.”

Both methane and CO2 are greenhouse gases, and methane actually traps more heat in the atmosphere than the commonly discussed CO2. In fact, it is 30 times more potent than CO2, Smallwood said.

New Study Could Help Reduce Agricultural Greenhouse Gas Emissions

Researchers developed a first-of-its-kind knowledge-guided machine learning model for agroecosystem, called KGML-ag that includes less obvious variables such as soil water content, oxygen level, and soil nitrate content related to nitrous oxide production and emission.
Credit: University of Minnesota College of Science and Engineering

A team of researchers led by the University of Minnesota has significantly improved the performance of numerical predictions for agricultural nitrous oxide emissions. The first-of-its-kind knowledge-guided machine learning model is 1,000 times faster than current systems and could significantly reduce greenhouse gas emissions from agriculture.

The research was recently published in Geoscientific Model Development, a not-for-profit international scientific journal focused on numerical models of the Earth. Researchers involved were from the University of Minnesota, the University of Illinois at Urbana-Champaign, Lawrence Berkeley National Laboratory, and the University of Pittsburgh.

Compared to greenhouse gases such as carbon dioxide and methane, nitrous oxide is not as well-known. In reality, nitrous oxide is about 300 times more powerful than carbon dioxide in trapping heat in the atmosphere. Human-induced nitrous oxide emissions (mainly from agricultural synthetic fertilizer and cattle manure) have also grown by at least 30 percent over the past four decades.

Turning a climate problem into a food solution

Like a mirage on the horizon, an innovative process for converting a potent greenhouse gas into a food security solution has been stalled by economic uncertainty. Now, a first-of-its-kind Stanford University analysis evaluates the market potential of the approach, in which bacteria fed captured methane grow into protein-rich fishmeal. The study, published Nov. 22 in Nature Sustainability, finds production costs involving methane captured from certain sources in the U.S. are lower than the market price for conventional fishmeal. It also highlights feasible cost reductions that could make the approach profitable using other methane sources and capable of meeting all global fishmeal demand.

“Industrial sources in the U.S. are emitting a truly staggering amount of methane, which is uneconomical to capture and use with current applications,” said study lead author Sahar El Abbadi, who conducted the research as a graduate student in civil and environmental engineering.

“Our goal is to flip that paradigm, using biotechnology to create a high-value product,” added El Abbadi, who is now a lecturer in the Civic, Liberal and Global Education program at Stanford.

From greenhouse gas to value-added product

Dogukan Apaydin, Dominik Eder, Hannah Rabl, electrochemical cell (from left)
Photo Credit: Dogukan Apaydin / TU Wien

If one converts CO2 into synthesis gas, a valuable starting material for the chemical industry can be obtained. Researchers at TU Wien show how this works even at room temperature and atmospheric pressure.

Thinking of CO2, terms like climate-damaging or waste product probably quickly come to mind. While CO2 has been that for a long time – a pure waste product – more and more processes are being developed with which the greenhouse gas can be converted into valuable raw materials. Researchers then speak of "value-added chemicals". A new material with which this is possible was developed at TU Wien and recently presented in the journal Communications Chemistry.

Researchers at Dominik Eder's group developed a new material that facilitates the conversion of CO2. These are MOCHAs – organometallic chalcogenolate compounds that serve as catalysts. The result of the electrochemical conversion is synthesis gas, or syngas for short, which is an important raw material for the chemical industry.

MethaneMapper is poised to solve the problem of underreported methane emissions

A central difficulty in controlling greenhouse gas emissions to slow down climate change is finding them in the first place.

Such is the case with methane, a colorless, odorless gas that is the second most abundant greenhouse gas in the atmosphere today, after carbon dioxide. Although it has a shorter life than carbon dioxide, according to the U.S. Environmental Protection Agency, it’s more than 25 times as potent as CO2 at trapping heat, and is estimated to trap 80 times more heat in the atmosphere than CO2 over 20 years.

 For that reason, curbing methane has become a priority, said UC Santa Barbara researcher Satish Kumar, a doctoral student in the Vision Research Lab of computer scientist B.S. Manjunath.

“Recently, at the 2022 International Climate Summit, methane was actually the highlight because everybody is struggling with it,” he said.

Even with reporting requirements in the U.S., methane’s invisibility means that its emissions are likely going underreported. In some cases, the discrepancies are vast, such as with the Permian Basin, an 86,000-square-mile oil and natural gas extraction field located in Texas and New Mexico that hosts tens of thousands of wells. Independent methane monitoring of the area has revealed that the site emits eight to 10 times more methane than reported by the field’s operators.

Greenhouse gas emissions are responsible for more than half of human pathogenic diseases

Source/Credit: University of Hawaiʻi

More than half of known human pathogenic diseases such as dengue, hepatitis, pneumonia, malaria, Zika and more, can be aggravated by climate change. That eye-opening and startling finding is the topic of a research paper published on August 8 in Nature Climate Change by a team of researchers from the University of Hawaiʻi at Mānoa.

The researchers carried out a systemic search for empirical examples about the impacts of 10 climatic hazards sensitive to greenhouse gas (GHG) emissions on each known human pathogenic disease. These hazards included warming, drought, heatwaves, wildfires, extreme precipitation, floods, storms, sea level rise, ocean biogeochemical change, and land cover change.

Combining two authoritative lists of all known infections and pathogenic diseases that have affected humanity in recorded history, researchers then reviewed over 70,000 scientific papers for empirical examples about each possible combination of a climatic hazard impacting each of the known diseases.

The research revealed that warming, precipitation, floods, drought, storm, land cover change, ocean climate change, fires, heatwaves and sea level changes were all found to influence diseases triggered by viruses, bacteria, animals, fungi, protozoans, plants and chromists. Pathogenic diseases were primarily transmitted by vectors, although case examples were also found for transmission pathways involving waterborne, airborne, direct contact and foodborne. Ultimately, the research found that more than 58%, or 218 out of 375, of known human pathogenic diseases had been affected at some point by at least one climatic hazard via 1,006 unique pathways.