Clean air policies having unintended impact driving up wetland methane emissions by up to 34 million tonnes

Impact of cleaner air means that human-emitted methane needs to fall more sharply to hit globally agreed targets

University of Birmingham

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Reducing sulphur in the air may inadvertently increase natural emissions of methane from wetlands such as peatlands and swamps, a new study has found.

The findings published today in the journal Science Advances suggests that the decline of global sulphur emissions as the result of clean air policies, coupled with the warming and fertilization effects of carbon dioxide emissions lifts a lid on wetland methane production resulting in increased emissions.

The resulting additional future release of 20-34 million tonnes of methane each year from natural wetlands would mean targets to reduce human-caused emissions need to be more stringent than currently set out in the Global Methane Pledge.

Methane, which is one of the most potent greenhouse gases in trapping heat in the atmosphere, is produced in wetlands around the world. Sulphur (in the form of sulphate) has a very specific effect in natural wetlands that reduces methane emissions, while CO2 increases methane production by increasing growth in plants that make the food for methane-producing microbes.

Professor Vincent Gauci from the University of Birmingham and a senior author of the study said:

“Well-meaning policies aimed at reducing atmospheric sulphur appear to be having the unintended consequence of lifting this sulphur ‘lid’ on wetland methane production. This coupled with increased CO2 means we have a double whammy effect that pushes emissions much higher.

“How has this happened? Put simply, sulphur provides the conditions for one set of bacteria to outmuscle another set of microbes that produce methane when they compete over the limited food available in wetlands. Under the conditions of acid rain sulphur pollution during the past century, this was enough to reduce wetland methane emissions by up to 8%.

“Now that clean air policies have been introduced, the unfortunate consequence of reducing sulphur deposition, which does have important and welcome effects for the world’s ecosystems, is that we will need to work much harder than we thought to stay within the safe climate limits set out in the Paris agreement.”

More than 150 nations signed up to the Global Methane Pledge at COP26 in Glasgow, which seeks to reduce human-caused emissions of methane by 30% on a 2020 baseline, by 2030.

The study is the latest to implicate reductions in atmospheric sulphur in driving warming at a faster rate than anticipated. In 2020 shipping pollution controls were introduced to reduce emissions of sulphur dioxide and fine particles that are harmful to human health. This reduction in atmospheric sulphur over the oceans has been implicated in larger warming that expected in what has come to be known as ‘termination shock’. 

Lead author of the paper Lu Shen of Peking University said:

“Our study points to the complexity of the climate system. Representation of these complex biogeochemical interactions has not previously been well integrated into estimates of future methane emissions. We show that it is essential to consider these feedbacks to get a true understanding of the likely future of this important greenhouse gas.”

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Journal

Science Advances

Article Title

The large role of declining atmospheric sulfate deposition and rising CO₂ concentrations in stimulating future wetland CH₄ emissions

Article Publication Date

5-Feb-2025

 

Scientists simulate asteroid collision effects on climate and plants

Institute for Basic Science

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image: 

Climatic and ecological responses to dust injections of 400 million tons from a Bennu-type asteroid impact. Spatial changes of surface temperature (upper left), total precipitation (upper right), percentage change of terrestrial net primary productivity (lower left) averaged over the first 24 months, and percentage change of marine net primary productivity (lower right) averaged from 10 to 38 months after the impact relative to the control simulation.

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Credit: Institute for Basic Science

A new climate modeling study published in the journal Science Advances by researchers from the IBS Center for Climate Physics (ICCP) at Pusan National University in South Korea presents a new scenario of how climate and life on our planet would change in response to a potential future strike of a medium-sized (~500 m) asteroid.

The solar system is full of objects with near-Earth orbits. Most of them do not pose any threat to Earth, but some of them have been identified as objects of interest with non-negligible collision probabilities. Among them is the asteroid Bennu with a diameter of about 500 m, which, according to recent studies [Farnocchia et al. 2021], has an estimated chance of 1-in-2700 of colliding with Earth in September 2182. This is similar to the probability of flipping a coin 11 times in a row with the same outcome.

To determine the potential impacts of an asteroid strike on our climate system and on terrestrial plants and plankton in the ocean, researchers from the ICCP set out to simulate an idealized collision scenario with a medium-sized asteroid using a state-of-the-art climate model. The effect of the collision is represented by a massive injection of several hundred million tons of dust into the upper atmosphere. Unlike previous studies, the new research also simulates terrestrial and marine ecosystems, as well as the complex chemical reactions in the atmosphere.

Using the IBS supercomputer Aleph, the researchers ran several dust impact scenarios for a Bennu-type asteroid collision with Earth. In response to dust injections of 100–400 million tons, the supercomputer model simulations show dramatic disruptions in climate, atmospheric chemistry, and global photosynthesis in the 3–4 years following the impact (Figure 1). For the most intense scenario, solar dimming due to dust would cause global surface cooling of up to 4˚C, a reduction of global mean rainfall by 15%, and severe ozone depletion of about 32%. However, regionally, these impacts could be much pronounced.

“The abrupt impact winter would provide unfavorable climate conditions for plants to grow, leading to an initial 20–30% reduction of photosynthesis in terrestrial and marine ecosystems. This would likely cause massive disruptions in global food security,” says Dr. Lan DAI, postdoctoral research fellow at the ICCP and lead author of the study.

When the researchers looked into ocean model data from their simulations, they were surprised to find that plankton growth displayed a completely different behaviour. Instead of the rapid reduction and slow two-year-long recovery on land, plankton in the ocean recovered already within 6 months and even increased afterwards to levels not even seen under normal climate conditions.

“We were able to track this unexpected response to the iron concentration in the dust,” says Prof. Axel TIMMERMANN, Director of the ICCP and co-author of the study. Iron is a key nutrient for algae, but in some areas, such as the Southern Ocean and the eastern tropical Pacific, its natural abundance is very low. Depending on the iron content of the asteroid and of the terrestrial material, that is blasted into the stratosphere, the otherwise nutrient-depleted regions can become nutrient-enriched with bioavailable iron, which in turn triggers unprecedented algae blooms. According to the computer simulations, the post-collision increase of marine productivity would be most pronounced for silicate-rich algae—referred to as diatoms. Their blooms would also attract large amounts of zooplankton—small predators, which feed on the diatoms.

“The simulated excessive phytoplankton and zooplankton blooms might be a blessing for the biosphere and may help alleviate emerging food insecurity related to the longer-lasting reduction in terrestrial productivity,” adds Dr. Lan DAI.

“On average, medium-sized asteroids collide with Earth about every 100–200 thousand years. This means that our early human ancestors may have experienced some of these planet-shifting events before with potential impacts on human evolution and even our own genetic makeup,” says Prof. Timmermann.

The new study in Science Advances provides new insights into the climatic and biospheric responses to collisions with near-Earth orbit objects. In the next step the ICCP researchers from South Korea plan to study early human responses to such events in more detail by using agent-based computer models, which simulate individual humans, their life cycles and their search for food.

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Journal

Science Advances

DOI

10.1126/sciadv.adq5399 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Climatic and ecological responses to Bennu-type asteroid collisions

Article Publication Date

5-Feb-2025

Meteorite discovery challenges long-held theories on Earth’s missing elements

Arizona State University

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image: 

Planetesimal collisions during planet formation in the early solar system. 

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Credit: Kouji Kanba

Understanding where Earth’s essential elements came from—and why some are missing—has long puzzled scientists. Now, a new study reveals a surprising twist in the story of our planet’s formation.

A new study led by Arizona State University’s Assistant Professor Damanveer Grewal from the School of Molecular Sciences and School of Earth and Space Exploration, in collaboration with researchers from Caltech, Rice University, and MIT, challenges traditional theories about why Earth and Mars are depleted in moderately volatile elements (MVEs). MVEs like copper and zinc play a crucial role in planetary chemistry, often accompanying life-essential elements such as water, carbon, and nitrogen. Understanding their origin provides vital clues about why Earth became a habitable world. Earth and Mars contain significantly fewer MVEs than primitive meteorites (chondrites), raising fundamental questions about planetary formation.

Published in Science Advances, the study takes a fresh approach by analyzing iron meteorites—remnants of the metallic cores of the earliest planetary building blocks— to uncover new insights.

“We found conclusive evidence that first-generation planetesimals in the inner solar system were unexpectedly rich in these elements,” said Grewal. “This discovery reshapes our understanding of how planets acquired their ingredients.”

Until now, scientists believed that MVEs were lost either because they never fully condensed in the early solar system or escaped during planetesimal differentiation. However, this study reveals a different story: many of the first planetesimals held onto their MVEs, suggesting that the building blocks of Earth and Mars lost theirs later—during a period of violent cosmic collisions that shaped their formation.

Surprisingly, the team found that many inner solar system planetesimals retained chondrite-like MVE abundances, showing that they accreted and preserved MVEs despite undergoing differentiation. This suggests that the progenitors of Earth and Mars did not start out depleted in these elements, but instead, their loss occurred over a prolonged history of collisional growth rather than incomplete condensation in the solar nebula or planetesimal differentiation. 

“Our work redefines how we understand the chemical evolution of planets,” Grewal explained. “It shows that the building blocks of Earth and Mars were originally rich in these life-essential elements, but intense collisions during planetary growth caused their depletion.”

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Journal

Science Advances

DOI

10.1126/sciadv.adq7848 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Enrichment of Moderately Volatile Elements in First-Generation Planetesimals of the Inner Solar System

Article Publication Date

5-Feb-2025

 

Phages love to kill bacteria. Could they be used as antibiotics?

University of California - San Francisco

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Scientists are learning more about how an intriguing type of virus protects itself. Revealing its strategies could boost the fight against antibiotic resistance.

Phages are viruses that attack bacteria by injecting their DNA, then usurping bacterial machinery to reproduce. Eventually, they make so many copies of themselves that the bacteria burst.

By looking at this process in a unique type of virus called a jumbo phage, scientists hope to learn how to make new antibiotics that can address the growing crisis of resistance.

The jumbo phage has more than four times the DNA of an average phage. It uses this genetic material to create a restricted space inside bacteria where it can copy its DNA while surrounded by a protective shield made of protein.

Researchers at UC San Francisco have discovered that the shield works via a set of “secret handshakes.” They allow only a specific set of useful proteins to pass through.

The handshakes all involve a large, central protein. It has a shape that lets it use different parts of itself to screen and recognize different proteins and grant them passage.

“This isn’t what we expected to see at all,” said Joseph Bondy-Denomy, PhD, associate professor of microbiology and immunology at UC San Francisco and senior author of the study, which appears Feb. 5 in Nature.

“It’s a surprisingly complicated thing for a phage to be doing,” he said.

Secret handshakes

Jumbo phages belong to a group of viruses called bacteriophages, or phages for short, which were discovered more than a century ago. Initially, phages were seen as a way to treat bacterial infections, because they are harmless to humans and can kill specific bacteria while leaving others alone. 

Interest died away once antibiotic drugs were developed, but the urgency to find new ways of fighting antibiotic-resistant bacteria is sparking it once again.

Scientists first began working on jumbo phages in the early 1980s but it wasn’t until 2017 that researchers at UCSF and UC San Diego worked together to identify the flexible protein that makes up the shield. 

In 2020, Bondy-Denomy led a study showing that the protein shield protects the phage’s DNA from attacks by the bacteria’s defenses.

He and Claire Kokontis, BS, a graduate student, suspected this shield may give jumbo phages distinct advantages over regular phages when it comes to using these viruses against infections.

The researchers wanted to learn how the shield recognizes the useful proteins and gives them passage into the protected area. 

The secret, they discovered, was a group of proteins made by the phage that interact in an unexpected way. 

At the center was a phage protein Kokontis called Importer1, or Imp1. For proteins to be imported into the protected space, they had to interact with Imp1. 

The researchers also found an additional set of importer proteins that assist Imp1 in bringing outside proteins through the shield. 

The interaction between Imp1 and a protein outside the shield needs to be just right before the protein gets the go-ahead to enter the protected area. 

“It’s like a secret handshake between two friends,” said Bondy-Denomy. “The ones that have the right handshake get the OK, and the others are tossed out.”

To see exactly what those handshakes looked like, Kokontis mapped the surface of the Imp1 “hand” at the molecular level. 

The map revealed that each phage protein that is allowed into the protected area has its own unique way of interacting with the Imp1 hand – one protein touches a thumb, another a finger, another a different finger. 

This variety of combinations allows the group of importer proteins to recognize an array of handshakes. 

A new way of making antibiotics

The researchers did their work using Pseudomonas bacteria, which they chose because it is notorious for its resistance to most antibiotics. 

What they learned will help scientists improve on an old approach that was left behind once antibiotics had become standard. Called phage therapy, it involves fighting one infection with another. First a human gets infected by bacteria. Then the human uses a phage to kill the bacteria. 

But bacteria are quick to evolve new defenses. Once they have devised a way to get past the phage’s protective shield, they will kill the phages.  

Understanding exactly how the shield’s secret handshakes work will help scientists engineer phages that can withstand these evolutionary changes. 

Bondy-Denomy’s lab has already developed a CRISPR-based method to make the necessary genetic changes to this specific family of phage. 

Scientists can also employ that knowledge to engineer jumbo phages that produce drugs or fight cancers caused by bacterial infections.

“We’re just at the starting point of realizing all this potential,” Kokontis said. “By getting a handle on the basic science of how these phages work, we’re laying the groundwork to adapt them for fighting disease.”

Authors: Other authors of this study are Timothy Klein and Sukrit Silas of UCSF

Funding: This work was funded by the NIH (grants R01 AI171041 and R01 AI167412).

 

About UCSF: The University of California, San Francisco (UCSF) is exclusively focused on the health sciences and is dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. UCSF Health, which serves as UCSF's primary academic medical center, includes top-ranked specialty hospitals and other clinical programs, and has affiliations throughout the Bay Area. UCSF School of Medicine also has a regional campus in Fresno. Learn more at ucsf.edu, or see our Fact Sheet.

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Journal

Nature

SEE

https://plawiuk.blogspot.com/search?q=PHAGES

 https://plawiuk.blogspot.com/search?q=BIOPHAGES

 https://plawiuk.blogspot.com/search?q=BACTERIOPHAGE

 

Recognizing Indigenous rights in environmental data

Researchers propose best practices for the governance of Indigenous data

Dartmouth College

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Every day across the globe, environmental scientists are collecting approximately 274 terabytes of data, a number that is growing thanks to advancements in science and technology.

The data, which ranges from soil composition to streamflows, is often collected or sampled from ecosystems that are stewarded by Indigenous peoples.

In a new Perspectives piece in Nature Communications, a group of researchers called the Earth Data Relations Working Group provide recommendations for how research practices can improve the governance of Indigenous data.

With the United Nations Declaration on the Rights of Indigenous Peoples having stated that Indigenous peoples have the right to self-determination, including the rights to protect the environment, including their lands, territories, and resources as well as their cultural and traditional knowledge, understanding how to handle and steward related data is an important issue.

"There is an abundance of data available about Indigenous homelands and even more being collected on a daily basis, but far too often Indigenous peoples and their governance practices are separated from the data," says lead author Lydia Jennings, a citizen of the Pascua Yaqui Tribe (Yoeme) and Huichol (Wixáritari) and an assistant professor of environmental studies at Dartmouth.

"Our work describes how principles such as the collective benefit and ethical governance of Indigenous data can be incorporated into ecological data practices that can align with already existing data infrastructures." 

The 18-member team included Indigenous and non-Indigenous scientists, with more than 14 distinct Indigenous peoples from regions throughout the U.S. and U.S. territories represented.

To align Indigenous rights and interests with big data and open science, Jennings and her fellow co-authors draw on themes of ethics and responsibility, collective benefits, and sustainability, including the Global Indigenous Data Alliance's CARE principles. 

They recommend that scientists examine current institutional practices and identify opportunities to improve communication and establish collaborative relationships with Indigenous rights holders. For example, researchers can explore how data can be aligned with Indigenous expertise and worldviews, so that the living relationships between people, places, animals, and ancestors are recognized.

"We really wanted to identify how to build out research infrastructures so that they can be more comprehensive of different knowledge systems," says Jennings, who is also chairing the new  Indigenous data governance task force for the Global Biodiversity Information Facility. 

Some of the other recommendations include examining the processes for gaining permission to access Indigenous sites such as applications for land and/or research permits, and improving protocols for data collection, and improving data and specimen management.

Applying cultural knowledge protocols could entail things like including Indigenous names associated with the place and origin of the material, which can in turn help increase Indigenous visibility and stewardship. As for managing specimens, researchers could explore the prospect of storing biological samples at Indigenous-run facilities on Indigenous land, which would recognize and acknowledge Indigenous worldviews.

As the co-authors report, establishing agreements with Indigenous partners and communities about the data related to Indigenous peoples, including who has the authority to grant access to it and protocols for when and how it may be made available or restricted is also an important part of the process. In some cases, tribal elders or other cultural keepers may need to be consulted on a project and its data.

Lastly, the team cautions that as Indigenous data is made available online, it needs to be cited properly, specifying if permission from Indigenous peoples was obtained, as appropriate, with guidance on how the content can be used.

"There's a global movement happening around building better data relationships to our ecological systems," says Jennings. "I think this type of work plants a seed to create a different type of scientific process that's more reciprocal in relationship with Indigenous communities that scientists are invited to work with. And so we're developing these types of processes to really be in a better relationship with one another."

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Journal

Nature Communications

DOI

10.1038/s41467-024-53480-2 

Method of Research

Commentary/editorial

Subject of Research

Not applicable

Article Title

Governance of Indigenous data in open earth systems science