Heat and drought change what forests breathe out

Qingyuan County forest research site
Photo Credit: Kai Huang/UCR

Scientists have long warned that rising global temperatures would force forest soils to leak more nitrogen gas into the air, further increasing both pollution and warming while robbing trees of an essential growth factor. But a new study challenges these assumptions. 

After six years of UC Riverside-led research in a temperate Chinese forest, researchers have found that warming may be reducing nitrogen emissions, at least in places where rainfall is scarce.

The findings, published in the Proceedings of the National Academy of Sciences, are the result of UCR’s collaboration with a large team of graduate students and postdoctoral researchers stationed in China’s Shenyang City. These researchers maintained the infrastructure used to take more than 200,000 gas measurements from forest soil over six years.

SwRI turbocharges its hydrogen-fueled internal combustion engine

SwRI has a multidisciplinary team dedicated to Hydrogen Energy Research initiatives to deploy decarbonization technologies across a broad spectrum of industries. In 2022, SwRI began modifying a heavy-duty natural gas-fueled engine to run on 100% hydrogen fuel, successfully demonstrated in 2024. SwRI continues to research, design and innovate on H2-ICE technology. 
Photo Credit: Southwest Research Institute

Southwest Research Institute (SwRI) has upgraded its hydrogen-powered heavy-duty internal combustion engine (H2-ICE) with a state-of-the-art turbocharger. The upgrades have significantly improved performance across the board, making the engine competitive with current long-haul diesel engines focused on fuel economy while maintaining near-zero tailpipe emissions.

In 2023, SwRI converted a traditional natural gas-fueled internal combustion engine to run solely on hydrogen fuel with minimal modifications. It was integrated into a Class-8 truck as part of the Institute’s H2-ICE project to demonstrate a cost-efficient hydrogen-fueled engine as an option for zero-tailpipe carbon dioxide heavy-duty transportation.

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. 

Higher methane emissions from warmer lakes and reservoirs may exacerbate worst-case climate scenario

Lakes are large sources of methane.
Photo Credit:Monica Westman

Emissions of the greenhouse gas methane from lakes and reservoirs risk doubling by the end of the century due to climate change according to a new study from Linköping University, Sweden, and NASA Ames Research Center in the US. This in turn could raise Earth’s temperature more than suggested by the UN climate panel IPCC’s current worst-case scenario. 

“This study makes it even clearer that we really, really want to change the climate scenario as quickly as possible. The future will be very uncertain if we don’t,” says Professor David Bastviken at Linköping University. 

Lakes and water reservoirs are some of the largest sources of methane on Earth. The methane emitted is largely formed as microorganisms decompose organic matter in oxygen-free environments. Before industrialization, natural methane emissions to the atmosphere were in balance with the methane breakdown processes. If the ongoing climate change disturbs the natural balance causing emissions to increase, global warming is at risk of worsening. 

New modeling shows difficult future for the GBR under climate change

Coral bleached by high water temperatures in the Pacific Ocean.
Photo Credit: Professor Peter Mumby

The most sophisticated modeling to date forecasts that under the current global emissions pathway the Great Barrier Reef could lose most of its coral by the end of the century, but curbing climate change and strategic management will help coral resilience.

A research team led by The University of Queensland simulated different future climate scenarios driven by a range of plausible global emissions trajectories.

Dr Yves-Marie Bozec from UQ’s School of the Environment said the comprehensive modelling of individual corals included their ability to adapt to warmer water, large-scale reef dynamics and their interconnections on ocean currents.

“We ran all of those factors with the most up to date climate projections – and the news was not good,” Dr Bozec said.

“We forecast a rapid coral decline before the middle of this century regardless of the emissions scenario.

“Corals may partially recover after 2050, but only if ocean warming is sufficiently slow to allow natural adaptation to keep pace with temperature changes.

“Adaptation may keep pace if global warming does not exceed 2 degrees by 2100.

“For that to happen, more action is needed globally to reduce carbon emissions which are driving climate change.”

Fermentation waste used to make natural fabric

 

Penn State Professor Melik Demirel, to the far right, his students and their families wear biomanufactured sweaters. Pictured are Khushank Singhal and Oguzhan Colak, both affiliated with the Department of Engineering Science and Mechanics in the College of Engineering; Ceren Colak, Ela Demirel and Emir Demirel.
Photo Credit: © Oguzhan Colak

A fermentation byproduct might help to solve two major global challenges: world hunger and the environmental impact of fast fashion. The leftover yeast from brewing beer, wine or even to make some pharmaceuticals can be repurposed to produce high-performance fibers stronger than natural fibers with significantly less environmental impact, according to a new study led by researchers at Penn State and published in the Proceedings of the National Academy of Sciences. 

The yeast biomass — composed of proteins, fatty molecules called lipids and sugars — left over from alcohol and pharmaceutical production is regarded as waste, but lead author Melik Demirel, Pearce Professor of Engineering and Huck Chair in Biomimetic Materials at Penn State, said his team realized they could repurpose the material to make fibers using a previously developed process. The researchers successfully achieved pilot-scale production of the fiber — producing more than 1,000pounds — in a factory in Germany, with continuous and batch production for more than 100 hours per run of fiber spinning.

They also used data collected during this production for a lifecycle assessment, which assessed the needs and impact of the product from obtaining the raw fermentation byproduct through its life to disposal and its cost, and to evaluate the economic viability of the technology. The analysis predicted the cost, water use, production output, greenhouse gas emissions and more at every stage. Ultimately, the researchers found that the commercial-scale production of the fermentation-based fiber could compete with wool and other fibers at scale but with considerably fewer resources, including far less land — even when accounting for the land needed to grow the crops used in the fermentation processes that eventually produce the yeast biomass.   

Unexpectedly high emissions from wastewater treatment plants

With a custom built drone, researchers at LiU have shown that greenhouse gas emissions from many wastewater treatment plants may be more than twice as large as previously thought.
Photo Credit: Magnus Gålfalk

Greenhouse gas emissions from many wastewater treatment plants may be more than twice as large as previously thought. This is shown in a new study from Linköping University, where the researchers used drones with specially manufactured sensors to measure methane and nitrous oxide emissions.

“We show that certain greenhouse gas emissions from wastewater treatment plants have been unknown. Now that we know more about these emissions, we also know more about how they can be reduced,” says Magnus Gålfalk, docent at Tema M – Environmental Change at Linköping University, who led the study published in the journal Environmental Science & Technology.

Wastewater treatment plants receiving sewage from households and industries account for approximately 5 per cent of human-induced methane and nitrous oxide emissions, according to the UN Intergovernmental Panel on Climate Change, IPCC.

To calculate this, the IPCC uses so-called emission factors that are linked to how many households are connected to the treatment plant. The calculation model then yields a number for the emissions from each wastewater treatment plant. This number is an estimate and not the result of actual measurements, which has turned out to be problematic.

Climate report: Earth on dangerous path but rapid action can avert the worst outcomes

Palisades Fire. Photo taken Jan. 8, 2025.
Photo Credit: Cal Fire.

2024 was the hottest year on record and likely the hottest in at least 125,000 years, according to an annual report issued by an international coalition led by Oregon State University scientists.

“Without effective strategies, we will rapidly encounter escalating risks that threaten to overwhelm systems of peace, governance, and public and ecosystem health,” said co-lead author William Ripple. “In short, we’ll be on the fast track to climate-driven chaos, a dangerous trajectory for humanity.”

Despite the sixth annual report’s ominous findings – 22 of the planet’s 34 vital signs are at record levels – Ripple stresses that “it’s not too late to limit the damage even if we miss the temperature mitigation goal set by the 2015 Paris Agreement,” an international treaty that set targets for reducing greenhouse gas emissions.

But with many vital signs, including greenhouse gas concentrations in the atmosphere, ocean acidity and ice mass, continuing to trend sharply in the wrong direction, the authors note that time is definitely of the essence.

Six-million-year-old ice discovered in Antarctica offers unprecedented window into a warmer Earth

Raising the Foro Drill, Allan Hills, Antarctica. 2022-2023.
Photo Credit: Julia Marks Peterson, COLDEX.

A team of U.S. scientists has discovered the oldest directly dated ice and air on the planet in the Allan Hills region of East Antarctica.

The 6-million-year-old ice and the tiny air bubbles trapped inside it provide an unprecedented window into Earth’s past climate, according to a new study published today in the Proceedings of the National Academy of Sciences.

The oldest ice sample from Allan Hills dated by researchers clocks in at 6 million years, from a period in Earth’s history where abundant geological evidence indicates much warmer temperatures and higher sea levels compared to today.

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.

Coronal mass ejections at the dawn of the solar system

Artist's depiction of a coronal mass ejection from EK Draconis. The hotter and faster ejection is shown in blue, while the cooler and slower ejection is shown in red.
Image Credit: National Astronomical Observatory of Japan

Down here on Earth we don't usually notice, but the Sun is frequently ejecting huge masses of plasma into space. These are called coronal mass ejections (CMEs). They often occur together with sudden brightenings called flares, and sometimes extend far enough to disturb Earth's magnetosphere, generating space weather phenomena including auroras or geomagnetic storms, and even damaging power grids on occasion.

Scientists believe that when the Sun and the Earth were young, the Sun was so active that these CMEs may have even affected the emergence and evolution of life on the Earth. In fact, previous studies have revealed that young Sun-like stars, proxies of our Sun in its youth, frequently produce powerful flares that far exceed the largest solar flares in modern history.

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.

A New Study Indicates Forest Regeneration Provides Climate Benefits, but Won’t Offset Fossil Fuels

Forest regrowth after 5 years since agricultural abandonment near Pucallpa, Ucayali, Peru.
Photo Credit: Jorge Vela Alvarado, Universidad Nacional de Ucayali

When farmland is abandoned and allowed to return to nature, forests and grasslands naturally regrow and absorb carbon dioxide from the atmosphere—helping fight climate change. However, a new study in the journal Global Biogeochemical Cycles, led by scientists at Columbia University, reveals an important wrinkle in this story: these regenerating ecosystems also release other greenhouse gases that reduce some of their climate benefits. The good news? Even accounting for these other gases, letting land regenerate naturally still provides important climate benefits compared with keeping it in agriculture.

Lead author Savannah S. Cooley, a research scientist at NASA Ames Research Center and a recent PhD graduate of Columbia’s Ecology, Evolution and Environmental Biology program, and her team of co-authors analyzed data from 115 studies worldwide to understand how forests and grasslands affect the climate through three key greenhouse gases: carbon dioxide, methane and nitrous oxide. While previous research focused mainly on carbon dioxide absorption by growing trees, this study examined a more complete picture.

Each fossil fuel project linked to additional global warming

Photo Credit: Roman Khripkov

Individual fossil fuel projects can no longer be considered too small to matter according to new Australian research linking each new investment in coal and gas extraction with measurable increases in global temperatures.

Published in the Nature journal Climate Action, climate scientists from six Australian universities, including the University of Melbourne, have revealed findings that debunk claims individual fossil fuel projects have little impact on global warming.

The research led by the ARC Centre of Excellence for the Weather of the 21st Century focused on the Scarborough gas project in Northwest Australia. It found that the project alone is estimated to lead to an increase of approximately 0.00039°C in global temperature from 876 million tons of CO2 emissions.

University of Melbourne Associate Professor Andrew King from the School of Geography, Earth and Atmospheric Sciences explained that while 0.00039°C of additional warming may seem relatively small, its impacts on society and the environment are actually large.

“This degree of warming could expose over half a million people to unprecedented extreme heat,” Associate Professor King said.

What Is: El Niño, La Niña, and a Climate in Flux

Image Credit: Scientific Frontline / NOAA

The Planet's Most Powerful Climate Cycle

In 1997, a climatic event of unprecedented scale began to unfold in the tropical Pacific Ocean. Dubbed the "El Niño of the century," it triggered a cascade of extreme weather that reshaped global patterns for over a year. It unleashed devastating floods and droughts, sparked massive forest fires, decimated marine ecosystems, and crippled national economies. By the time it subsided in 1998, the event was estimated to have caused more than 22,000 deaths and inflicted over $36 billion in damages worldwide. Nearly two decades later, the powerful 2015-16 El Niño, supercharged by a background of long-term global warming, helped propel 2016 to become the hottest year on record and directly impacted the lives and livelihoods of over 60 million people.

These catastrophic events are not random acts of nature but manifestations of the planet's most powerful and influential climate cycle: the El Niño-Southern Oscillation (ENSO). This naturally occurring phenomenon is a periodic, irregular fluctuation of sea surface temperatures and atmospheric pressure across the vast expanse of the equatorial Pacific Ocean. At its heart are two opposing phases: El Niño ("The Little Boy" in Spanish), a significant warming of the ocean surface, and La Niña ("The Little Girl"), a countervailing cooling. Together with a neutral "in-between" state, they form a planetary-scale pendulum that swings irregularly every two to seven years, dictating patterns of drought and flood, storm and calm, across the globe.

Green Energy and Innovation Can Increase Greenhouse Gas Emissions

The introduction of renewable energy sources in developing Asian countries may lead to a short-term increase in greenhouse gas emissions.
Photo Credit: Nicholas Doherty

Scientists at Ural Federal University have found that the introduction of renewable energy sources (RES) and technological innovations in developing Asian countries can lead to a short-term increase in greenhouse gas emissions. The reason is the effect of rebound and insufficient effectiveness of regulatory systems. This calls into question the effectiveness of current measures to achieve the goals of the Paris Agreement, the researchers believe. They wrote on this topic in an article in the journal Energy Economics.

"In Asia, more efficient coal-fired power plants or cheaper solar energy can lower electricity prices, leading to increased energy consumption by industry and households in general. Although innovations reduce CO₂ emissions in the short term, they actually increase emissions in the medium and long term, as efficiency gains drive growth in industrial activity and energy demand. This is a classic rebound effect: efficiency stimulates economies of scale, negating the initial environmental benefits," explained Kazi Sohag, co-author of the paper and head of the UrFU Laboratory of Economic Policy and Natural Resources.

Clam shells sound warning of Atlantic ‘tipping point’

Ocean quahog shells.
Photo Credit Paul Butler

A study of clam shells suggests Atlantic Ocean currents may be approaching a “tipping point”.

Scientists studied records of quahog clams (which can live for over 500 years) and dog cockles – because shell layers provide an annual record of ocean conditions.

They studied these natural archives to understand long-term patterns in Atlantic Ocean currents such as the Atlantic Meridional Overturning Circulation (AMOC) and the subpolar gyre (SPG).

Recent studies have debated possible AMOC and SPG tipping points – transitions that would transform climate patterns. For example, AMOC collapse would have far-reaching global effects, from harsher winters in north-west Europe to shifts in global rainfall patterns, while a weakening of the SPG would be less catastrophic but still bring substantial impacts, including more frequent extreme weather in the North Atlantic region.

Rapid flash Joule heating technique unlocks efficient rare‑earth element recovery from electronic waste

The research team’s method uses flash Joule heating.
Photo Credit: Jeff Fitlow/Rice University.

A team of researchers including Rice University’s James Tour and Shichen Xu has developed an ultrafast, one-step method to recover rare earth elements (REEs) from discarded magnets using an innovative approach that offers significant environmental and economic benefits over traditional recycling methods. Their study was published in the Proceedings of the National Academy of Sciences Sept. 29, 2025.

Conventional rare earth recycling is energy-heavy and creates toxic waste. The research team’s method uses flash Joule heating (FJH), which rapidly raises material temperatures to thousands of degrees within milliseconds, and chlorine gas to extract REEs from magnet waste in seconds without needing water or acids. The breakthrough supports U.S. efforts to boost domestic mineral supplies.

“We’ve demonstrated that we can recover rare earth elements from electronic waste in seconds with minimal environmental footprint,” said Tour, the T.T. and W.F. Chao Professor of Chemistry, professor of materials science and nanoengineering and study corresponding author. “It’s the kind of leap forward we need to secure a resilient and circular supply chain.”

Turning Plastic Waste into Fuel

Ali Kamali, a doctoral candidate in chemical and biomolecular engineering, inspects a sample of liquid fuel created from plastics.
Photo Credit: Kathy F. Atkinson

Plastics are valued for their durability, but that quality also makes it difficult to break down. Tiny pieces of debris known as microplastics persist in soil, water and air and threaten ecosystems and human health. Traditional recycling reprocesses plastics to make new products, but each time this is done, the material becomes lower in quality due to contamination and degradation of the polymers in plastics. Moreover, recycling alone cannot keep pace with the growing volume of global plastic waste.

Now, a University of Delaware-led research team has developed a new type of catalyst that enhances conversion of plastic waste into liquid fuels more quickly and with fewer undesired byproducts than current methods. Published in the journal Chem Catalysis, the pilot-stage work helps pave the way toward energy-efficient methods for plastic upcycling, reducing plastic pollution and promoting sustainable fuel production.

“Instead of letting plastics pile up as waste, upcycling treats them like solid fuels that can be transformed into useful liquid fuels and chemicals, offering a faster, more efficient and environmentally friendly solution,” said senior author Dongxia Liu, the Robert K. Grasseli Professor of Chemical and Biomolecular Engineering at UD’s College of Engineering.

Methane production may increase as Arctic lakes warm

 

Fältarbete vid sjöar nära Abisko naturvetenskapliga station.
Photo Credit: Sofia Kjellman

A warmer and wetter climate makes lakes more productive – which in turn leads to more methane being released from sediments. A new study involving Umeå University shows that Arctic lakes may contribute even more to the greenhouse effect in the future.

Methane is more than 25 times stronger as a greenhouse gas than carbon dioxide. Arctic lakes account for a significant share of global methane emissions, but until now, knowledge about the processes in northern lakes has been limited. An international team of researchers from Norway, Sweden and Spain has now shown that methane production varies greatly between lakes and is closely linked to their characteristics.

The researchers investigated ten lakes on Svalbard and in the subarctic region of Scandinavia, three of them via the Abisko Scientific Research Station. They found that most methane production occurs in the top ten centimeters of lake sediments, where there is abundant organic matter and favorable conditions for microbes.