Counting salmon is a breeze with airborne eDNA

A male Coho salmon, featuring the characteristic hooked nose, returns to spawn from the Oregon Coast.
Photo Credit: NOAA Fisheries

During the annual salmon run last fall, University of Washington researchers pulled salmon DNA out of thin air and used it to estimate the number of fish that passed through the adjacent river. Aden Yincheong Ip, a UW research scientist of marine and environmental affairs, began formulating the driving hypothesis for the study while hiking on the Olympic Peninsula.

“I saw the fish jumping and the water splashing and I started thinking — could we recover their genetic material from the air?,” he said.

The researchers placed air filters at several sites on Issaquah Creek, near the Issaquah Salmon Hatchery in Washington. To their amazement, the filters captured Coho salmon DNA, even 10 to 12 feet from the river. Scientists collect environmental DNA, or eDNA, to identify species living in or passing through an area, but few have attempted to track aquatic species by sampling air.

Clean biogas – measurable everywhere

Ayush Agarwal worked on the analysis of biogas during his doctoral studies at the PSI Center for Energy and Environmental Sciences at PSI.
Photo Credit: © Paul Scherrer Institute PSI/Markus Fischer

Researchers at the Paul Scherrer Institute PSI have developed a new analytical method that can detect even tiny amounts of critical impurities in biogas. This procedure can be used even by small biogas plants without the need for major investment – thus facilitating the energy transition.

The market for biogas is growing. According to the Swiss Federal Office of Energy, Switzerland fed 471 gigawatt hours of this fuel into the natural gas grid last year – roughly twice the amount fed in ten years ago. This comes with an increase in the need to measure impurities in the biogas quickly and reliably, because strict quality criteria apply to this green gas.  

Researchers at PSI’s Center for Energy and Environmental Sciences have now come up with a solution to this problem. The analytical method they have developed can simultaneously detect the two most critical impurities in biogas: sulfur compounds and siloxanes. They have now presented their method in the journal Progress in Energy. 

Researchers Warn: Climate Change Could Expand Habitats for Malaria Mosquitoes

“Our climate scenarios show that we can prevent much of this by limiting climate change.," says lead author of the study, Tiem van der Deure.
Illustration Credit: University of Copenhagen

An insistent buzzing at sunset followed by itchy, spotted legs. Here in Denmark, mosquitoes are mostly an annoying – but generally harmless – nuisance. That is far from the case in many parts of the world. 

Every year, around 600,000 people die from malaria, a mosquito-borne disease – most of them in sub-Saharan Africa, and children are the most vulnerable. This makes malaria one of the deadliest infectious diseases globally. 

A new study from the University of Copenhagen, published in Global Change Biology, shows that future climate change could create more favorable conditions for malaria mosquitoes, exposing millions of people across large parts of Africa to more dangerous mosquito bites.  

Over half of global coastal settlements are retreating inland due to intensifying climate risks

Hurricane Florence moved toward the U.S. East Coast as it intensified to a Category 4 storm, with one-minute sustained winds of 130 mph Monday September 10, 2018. This image, captured by the GOES East satellite at 10:00 am ET, showed Florence in the western Atlantic, about 600 miles southeast of Bermuda, at Category 3 intensity. The storm had developed a small but well-defined eye and a symmetrical appearance typical of major hurricanes that are rapidly intensifying.
Image Credit: NOAA

For centuries, coastlines have attracted dense human settlement and economic activity. Today, more than 40 percent of the global population lives within 100 kilometers of the coast, facing accelerating sea-level rise, coastal erosion, flooding, and tropical cyclones. 

Although moving away from the coast - known as “retreat” - is often viewed as an adaptive strategy, its global extent and drivers have remained unclear. A new study published in Nature Climate Change fills this gap by providing the first global evidence that coastal retreat is driven more by social and infrastructural vulnerability than by historical exposure to hazards. 

The study was conducted by an international team led by researchers from Sichuan University and included remote sensing experts from the University of Copenhagen (Alexander Prishchepov and Shengping Ding, IGN). It maps settlement movements across 1,071 coastal regions in 155 countries. By integrating nighttime light observations with global socioeconomic datasets, the researchers found that 56% of coastal regions have retreated from the coast from 1992 to 2019, and 16% of regions, including the Copenhagen area in Denmark, have moved closer to the coast, while 28% have remained stable. 

Scientific Models Overestimate Natural Processes That Mitigate Climate Change

Silky lupine plants at Lassen National Park in California
Photo Credit: Duncan Menge

High levels of atmospheric carbon dioxide intensify climate change, but high carbon dioxide levels can also stimulate plant growth. Plant growth removes carbon dioxide from the atmosphere, partially mitigating the effects of climate change. However, plants only grow faster in the presence of high levels of carbon dioxide if they can also acquire enough nitrogen from the atmosphere to do so. The actual amount of nitrogen acquired from the atmosphere was reassessed in a study co-led by Columbia faculty that was released this summer; it was shown to be significantly lower than previously estimated.

Microplastics pose a human health risk in more ways than one

Bio-beads collected near Truro.
Photo Credit Beach Guardian

A new study shows that microplastics in the natural environment are colonized by pathogenic and antimicrobial resistant bacteria. The study team calls for urgent action for waste management and strongly recommends wearing gloves when taking part in beach cleans. 

Microplastics are plastic particles less than 5mm in size and are extremely widespread pollutants. It is estimated that over 125 trillion particles have accumulated in the ocean (surface to seabed) and they have also been detected in soils, rivers, lakes, animals and the human body. 

An emerging concern associated with microplastics is the microbial communities that rapidly make their home on the particle surface, forming complex biofilms known as the “Plastisphere”. These communities may often include pathogenic (disease-causing) or antimicrobial resistant (AMR) bacteria. 

Antarctic mountains could boost ocean carbon absorption

Glaciers transport sediments from Antarctica to the coast.
Photo Credit: Dr Kate Winter, Northumbria University

Research involving scientists from Newcastle University has revealed new hope in natural environmental systems found in Antarctica which could help mitigate the overall rise of carbon dioxide. 

As Antarctica's ice sheets thin due to climate change, newly exposed mountain peaks could significantly increase the supply of vital nutrients to the Southern Ocean which surrounds the continent, potentially enhancing its ability to absorb atmospheric carbon dioxide over long timescales, according to the research published in Nature Communications. 

Led by Northumbria University, a team of scientists looked at analysis of sediment samples from East Antarctica's Sør Rondane Mountains. They discovered that weathered rocks exposed above the ice surface contain iron concentrations up to ten times higher than previously reported from the Antarctic continent. This bioavailable iron is transported to the ocean by glaciers and icebergs, where it fuels the growth of phytoplankton – microscopic marine organisms that absorb CO₂ through photosynthesis. 

Environmental Science: In-Depth Description

Photo Credit: Esa Kaifa

Environmental science is an interdisciplinary academic field that integrates physical, biological, and information sciences to study the environment and identify solutions to environmental problems. By combining disciplines such as ecology, biology, physics, chemistry, plant science, zoology, mineralogy, oceanography, limnology, soil science, geology and physical geography, and atmospheric science, it seeks to understand the complex interactions between the natural world and human societies.

The primary goal of environmental science is to learn how the natural world works, to understand how we interact with the environment, and to determine how we can live sustainably without degrading our life-support system.

5,500 toxic sites in U.S. at risk of flooding because of sea level rise

U.S. face rising flood risks due to sea-level rise.
Photo Credit: Wes Warren

More than 5,500 hazardous sites across the U.S. are projected to be at risk of coastal flooding by 2100, according to newly published research led by University of California scientists.

The researchers found that if heat-trapping pollution grows unchecked, rising sea levels will flood a wide range of sites, including facilities that handle sewage, toxic waste, oil and gas, and other industrial pollutants, posing serious threats to public health and neighboring communities. The peer-reviewed study — Sea level rise and flooding of hazardous sites in marginalized communities across the United States – was just published in the London-based scientific journal Nature Communications. 

Study shows waste cardboard is effective for power generation

Photo Credit: Jon Moore

A new study has shown for the first time that waste cardboard can be used as an effective source of biomass fuel for large scale power generation. 

Engineers from the University of Nottingham have provided the first comprehensive characterization of cardboard as a potential fuel source and created a new method to assess the composition of the material providing a practical tool for fuel assessment for cardboards. The study has been published in the journal Biomass and Bioenergy. 

Human biology is ill-adapted to modern cities

A new study has found that modern cities are having a huge impact on our health and wellbeing.
Photo Credit: Patrick Robert Doyle

Researchers from Loughborough University and the University of Zurich found that rapid industrialization has reshaped human habitats so dramatically that our biology may no longer be able to keep up. 

The paper, published in Biological Reviews, highlights that densely populated, polluted, and industrialized environments are impairing core biological functions essential for survival and reproduction (i.e., the ‘evolutionary fitness’ of our species). 

Microplastics hit male arteries hard

Changcheng Zhou Professor, Biomedical Sciences
Photo Credit: Courtesy of University of California, Riverside

A mouse study led by University of California, Riverside biomedical scientists suggests that everyday exposure to microplastics — tiny fragments shed from packaging, clothing, and countless plastic products — may accelerate the development of atherosclerosis, the artery-clogging process that leads to heart attacks and strokes. The harmful effects were seen only in male mice, offering new clues about how microplastics may affect cardiovascular health in humans.

“Our findings fit into a broader pattern seen in cardiovascular research, where males and females often respond differently,” said lead researcher Changcheng Zhou, a professor of biomedical sciences in the UCR School of Medicine. “Although the precise mechanism isn’t yet known, factors like sex chromosomes and hormones, particularly the protective effects of estrogen, may play a role.”

Researchers link Antarctic ice loss to ‘storms' at the ocean's subsurface

Mattia Poinelli, a UC Irvine postdoctoral scholar in Earth system science and NASA JPL research affiliate, outlines in a newly published study the impact of submesoscale events – small, subsurface ocean eddies and vortices – on Antarctica’s ice sheets. “Despite being largely overlooked in the context of ice-ocean interactions,” he says, “[they] are among the primary drivers of ice loss.”
Photo Credit: Steve Zylius / UC Irvine

Researchers at the University of California, Irvine and NASA’s Jet Propulsion Laboratory have identified stormlike circulation patterns beneath Antarctic ice shelves that are causing aggressive melting, with major implications for global sea level rise projections.

In a paper published recently in Nature Geoscience, the scientists say their study is the first to examine ocean-induced ice shelf melting events from a weather timescale of just days versus seasonal or annual timeframes. This enabled them to match “ocean storm” activity with intense ice melt at Thwaites Glacier and Pine Island Glacier in the climate change-threatened Amundsen Sea Embayment in West Antarctica.

The research team relied on climate simulation modeling and moored observation tools to gain 200-meter-resolution pictures of submesoscale ocean features between 1 and 10 kilometers across, tiny in the context of the vast ocean and huge slabs of floating ice in Antarctica.

Floating solar panels show promise, but environmental impacts vary by location

The Canoe Brook Floating Solar Photovoltaic (FPV) project, the largest in the United States at the time of completion at 8.9 MW, is located on a water storage reservoir is New Jersey.
Photo Credit Prateek Joshi / NREL

Floating solar panels are emerging as a promising clean energy solution with environmental benefits, but a new study finds those effects vary significantly depending on where the systems are deployed.

Researchers from Oregon State University and the U.S. Geological Survey modeled the impact of floating solar photovoltaic systems on 11 reservoirs across six states. Their simulations showed that the systems consistently cooled surface waters and altered water temperatures at different layers within the reservoirs. However, the panels also introduced increased variability in habitat suitability for aquatic species.

“Different reservoirs are going to respond differently based on factors like depth, circulation dynamics and the fish species that are important for management,” said Evan Bredeweg, lead author of the study and a former postdoctoral scholar at Oregon State. “There’s no one-size-fits-all formula for designing these systems. It’s ecology - it’s messy.”

Wastewater from most countries favors non-resistant bacteria

Joakim Larsson, Professor at the Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, and director of CARe, Centre for Antibiotic Resistance Research.
Photo Credit: Johan Wingborg

A global study led by researchers at the Centre for Antibiotic Resistance Research (CARe) in Gothenburg, Sweden shows that municipal wastewater is not always the breeding ground for antibiotic resistance it is often thought to be. By testing wastewater from 47 countries, the team found that while some samples could select for resistant E. coli, the majority instead selected against resistance. These insights reshape our understanding of when and where resistance is likely to evolve and spread. 

Municipal wastewater contains a large range of excreted antibiotics and has therefore long been suspected to be a spawning ground for antibiotic-resistant bacteria. Now, a study published in Nature Communications led by a team from the University of Gothenburg provides a more nuanced picture. 

A Microbial Blueprint for Climate-Smart Cows

Matthias Hess, with the UC Davis Department of Animal Science, and researchers at UC Berkeley, have identified which microbes in a cow's gut could help reduce methane. It brings them a step closer to engineering gut microbes to create more climate-friendly cows.
Photo Credit: Gregory Urquiaga / UC Davis

Each year, a single cow can belch about 200 pounds of methane. The powerful greenhouse gas is 27 times more potent at trapping heat in the atmosphere than carbon dioxide. For decades, scientists and farmers have tried to find ways to reduce methane without stunting the animal’s growth or productivity. 

Recent research at University of California, Davis, has shown that feeding cows red seaweed can dramatically cut the amount of methane that is produced and released into the environment. Until now, however, scientists did not fully understand how red seaweed changes the interactions among the thousands of microbes in the cow’s gut, or rumen. 

Wheat could use far more water than expected during future heatwaves

Dr Robert Caine
Photo Credit: Courtesy of University of Sheffield

Wheat crops prioritize water loss during extreme future climate conditions, according to new research from the University of Sheffield 

The study, led by Dr Robert Caine and Dr Holly Croft from the School of Biosciences at the University of Sheffield, revealed wheat crops lose many of the key water-saving benefits usually associated with growth at higher atmospheric concentrations of carbon dioxide when plants were exposed to heatwave conditions. 

These findings are vital for understanding how to optimize future wheat crop productivity and water usage. With heatwaves becoming increasingly routine as atmospheric CO2 concentration continues to rise, plant breeders will need to consider how crops use and conserve water when developing new wheat varieties to ensure it can grow effectively and survive extreme weather. 

New study finds higher hantavirus risk in drier, underdeveloped areas

A study of the long-term risk of contracting hantavirus across large geographic areas provides public health officials with information about populations most at risk for contracting hantavirus and the potential drivers of disease risk. Humans become infected with hantavirus when they inhale the airborne particles of feces and urine of disease-carrying rodents.
Photo Credit: Zoshua Colah

In a recent study of the contiguous United States, Los Alamos National Laboratory researchers found that the risk of disease from hantavirus is higher in drier, underdeveloped geographic areas with more socioeconomic vulnerability and increased numbers of unique rodent species. This is the first study to examine the combined effects of multiple variables — including socioeconomic, environmental, land use and rodent species — to determine which are most likely to predict the risk of people contracting hantavirus.

“We ran each of these variables separately — looking at where people are most at risk given just the environmental variables, just the land-use variables, etc. — and then we combined them all,” said Morgan Gorris, a scientist at Los Alamos and lead author on the study published in Transboundary and Emerging Diseases. “This gave us a map of where people are most at risk of being exposed to hantavirus and contracting hantavirus pulmonary syndrome (HPS).”

Carbon-rich waters are becoming even more acidic as atmospheric CO2 levels rise

Orange cup corals, pictured growing on rocks above, are native to the Pacific Ocean. As they grow, corals incorporate minerals from seawater, leaving a valuable historical record in their skeletons. In this University of Washington-led study, researchers compare preindustrial corals to modern specimens to show how quickly the ocean is acidifying.
Photo Credit: Alexander Vasenin
(CC BY-SA 4.0)

The waters bordering North America could soon be inhospitable to critical marine creatures if the Northeastern Pacific Ocean continues to acidify at the current rate, a new study shows.

Earth’s oceans have become approximately 30% more acidic since the industrial revolution began more than 200 years ago. Acidification changes marine chemistry and depletes key minerals that calcifying organisms, such as corals and clams, need to build their skeletons and shells. The Northeastern Pacific is naturally more acidic than other oceans, fueling debate about how much its chemistry will change in the coming decades.

The study, published in Nature Communications, shows that high baseline acidity makes the water more sensitive to additional carbon dioxide from human activities. Analyses of coral skeletons from the past century revealed that CO2 has been accumulating in North American waters faster than in the atmosphere, driving rapid acidification.

Fossil fuel CO2 emissions hit record high in 2025

Photo Credit: Chris LeBoutillier

Global carbon emissions from fossil fuels are projected to rise by 1.1% in 2025 – reaching a record high, according to new research by the Global Carbon Project. 

The 2025 Global Carbon Budget projects 38.1 billion tons of fossil carbon dioxide (CO2) emissions this year. 

Decarbonization of energy systems is progressing in many countries – but this is not enough to offset the growth in global energy demand. 

With projected emissions from land-use change (such as deforestation) down to 4.1 billion tons in 2025, total CO2 emissions are projected to be slightly lower than last year. 

With the end of the 2023-24 El Niño weather pattern – which causes heat and drought in many regions – the land “sink” (absorption of CO2 by natural ecosystems) recovered this year to the pre-El Niño level.