Carbon dioxide emissions from China have flatlined or fallen for 21 months, meaning the world's biggest greenhouse gas emitter may have reached a global turning point sooner than expected.

China's carbon dioxide (CO2) emissions dropped by 1% in the last quarter of 2025 and likely by 0.3% over the whole year, keeping them just beneath the record highs reached in May 2024, according to a new analysis by the Finland-based Centre for Research on Energy and Clean Air (CREA) for Carbon Brief. The nearly two-year flatline or fall is the longest on record not driven by an economic slowdown in the country, which emits over a third of global CO2.

If the trend holds, China's emissions could reach an all-time peak before 2030 — the country's official target date — or even sooner, marking a key win in the global effort to curb fossil fuel use and slow global warming. Yet whether the drop is sustained or demand will drive a rebound in emissions before the officially targeted peak remains an open question.

The Trump administration on Thursday revoked a scientific finding that long has been the central basis for U.S. action to regulate greenhouse gas emissions and fight climate change, the most aggressive move by the president to roll back climate regulations.

The rule finalized by the Environmental Protection Agency rescinds a 2009 government declaration known as the endangerment finding that determined that carbon dioxide and other greenhouse gases endanger public health and welfare.

The endangerment finding by the Obama administration is the legal underpinning of nearly all climate regulations under the Clean Air Act for motor vehicles, power plants and other pollution sources that are heating the planet.

President Donald Trump called the move "the single largest deregulatory action in American history," while EPA Administrator Lee Zeldin called the endangerment finding "the Holy Grail of federal regulatory overreach."

EPA has a clear scientific and legal obligation to regulate greenhouse gases, McCarthy said, adding that evidence backing up the endangerment finding "has only grown stronger" as the health and environmental hazards of climate change have "become impossible to ignore."

A kidney transplant can be life-changing, but it usually comes with a lifelong tradeoff: daily immunosuppressant pills that keep the immune system from attacking the donated organ.

A new study suggests there may be another path in the future, one that could reduce the daily medication burden to a monthly treatment. Researchers say the goal is not just convenience. The approach could also limit side effects and help donor kidneys keep working longer.

Right now, most kidney transplant recipients take several drugs every day to prevent rejection. While these standard immunosuppressants protect the new kidney, they can gradually harm kidney function and may lose effectiveness over time.

Hatches open! Four SpaceX Crew-12 crew members have entered the station and joined Expedition 74 to begin a long-duration space research mission. More... go.nasa.gov/4twQhDf

Ancient Egyptian mummies have a distinctive odor known only to those who've gotten close enough for a sniff. Now, scientists have captured these invisible vapors to find clues about the way they were embalmed.

Usually, archeologists take a more invasive approach to mummy analysis by cutting away a piece of bandage and dissolving it to get a read on the molecular makeup of embalming agents.

But this process is inherently destructive. Sometimes the molecules fall apart in the process. And there are only so many pieces of bandage you can take before the entire mummy unravels.

Instead, a team of organic geochemists from the University of Bristol realized they could sample volatile organic compounds (VOCs) from the air surrounding the mummy. VOCs are molecules that rise readily from their source and spread through the air, hitting your nostrils with their unique scent signatures.

In a set of carefully designed experiments modeled on children’s tea parties, researchers at Johns Hopkins University found that an ape could engage in pretend play. The results mark the first controlled demonstration that an ape can imagine objects that are not actually there, a skill long considered uniquely human.

Across three separate tests, the bonobo interacted with invisible juice and imaginary grapes in a consistent and reliable way. The performance challenges longstanding assumptions about the limits of animal cognition.

The researchers conclude that the ability to understand pretend objects falls within the mental capacities of at least one enculturated ape. They suggest this ability could trace back 6 to 9 million years to a common ancestor shared by humans and other apes.

Ape Imagination Upends Human Uniqueness in Science Study
“It really is game-changing that their mental lives go beyond the here and now,” said co-author Christopher Krupenye, a Johns Hopkins assistant professor in the Department of Psychological and Brain Sciences who studies how animals think. “Imagination has long been seen as a critical element of what it is to be human, but the idea that it may not be exclusive to our species is really transformative.

“Jane Goodall discovered that chimps make tools, and that led to a change in the definition of what it means to be human, and this, too, really invites us to reconsider what makes us special and what mental life is out there among other creatures.”

The musk oxen’s strength lies in their unity, but even the tightest herd can be broken by a relentless pack of Arctic wolves.

A new study from U of T Scarborough suggests that mental sharpness is not just a feeling. When people’s thinking is clearer and more efficient, their daily output can look like they added roughly 40 extra minutes of productive work.

The research, published in Science Advances, followed people for 12 weeks and focused on changes within the same individual over time, not differences between individuals. That design matters because it helps separate temporary mental states from more stable qualities such as baseline ability or personality. The team found that everyday swings in sharpness helped explain why someone might confidently plan their day and then struggle to act on it.

“Some days everything just clicks, and on other days it feels like you’re pushing through fog,” says Cendri Hutcherson, associate professor in the Department of Psychology at U of T Scarborough and lead author of the study.

“What we wanted to understand was why that happens, and how much those mental ups and downs actually matter.”

What Researchers Mean by Mental Sharpness
In this study, mental sharpness refers to how efficiently the brain is operating in the moment. It reflects how readily someone can keep attention on track, make choices, set targets, and then follow through. When that system is running well, tasks can feel straightforward. When it is not, even basic steps can start to drag.

Going to space is harsh on the human body, and as a new study from our research team finds, the brain shifts upward and backward and deforms inside the skull after spaceflight.

The extent of these changes was greater for those who spent longer in space. As NASA plans longer space missions, and space travel expands beyond professional astronauts, these findings will become more relevant.

Why it matters
On Earth, gravity constantly pulls fluids in your body and your brain toward the center of the Earth. In space, that force disappears. Body fluids shift toward the head, which gives astronauts a puffy face. Under normal gravity, the brain, cerebrospinal fluid and surrounding tissues reach a stable balance. In microgravity, that balance changes.

The International Space Station returned to full strength with Saturday's arrival of four new astronauts to replace colleagues who bailed early because of health concerns.

SpaceX delivered the U.S., French and Russian astronauts a day after launching them from Cape Canaveral.

Last month's medical evacuation was NASA's first in 65 years of human spaceflight. One of four astronauts launched by SpaceX last summer suffered what officials described as a serious health issue, prompting their hasty return. That left only three crew members to keep the place running—one American and two Russians—prompting NASA to pause spacewalks and trim research.

Moving in for eight to nine months are NASA's Jessica Meir and Jack Hathaway, France's Sophie Adenot and Russia's Andrei Fedyaev. Meir, a marine biologist, and Fedyaev, a former military pilot, have lived up there before. During her first station visit in 2019, Meir took part in the first all-female spacewalk.

This video of cornflower root hairs, captured by Wim van Egmond, shows the single-cell extensions on the cornflower's roots. See more from the microscopic world: on.natgeo.com/4qyGUQR

Scientists have teamed up to build a new kind of filtration membrane designed for unusually sharp molecular sorting.

Reported in the Journal of the American Chemical Society, the approach could cut the energy cost of industrial purification and make large-scale water reuse more achievable.

A huge share of manufacturing depends on “separations.” That single word covers everything from removing unwanted byproducts during drug making to stripping color from textile wastewater to refining ingredients in food processing. Today, many of these steps still lean on distillation and evaporation, which work well but burn vast amounts of energy and add significantly to industrial carbon emissions.

Membrane systems are often viewed as a cleaner alternative because they can separate chemicals without repeatedly heating and cooling large volumes, but common polymer membranes have a persistent weakness: their pores vary in size and can change as the material ages. When the pore landscape shifts, selectivity drops, and that is a deal breaker for precision work.

A New Class of Crystalline Membranes
“To address these limitations, we engineered a new class of ultra-selective, crystalline membranes called “POMbranes”, which contain pores that are about one nanometer wide, thousands of times thinner than a human hair,” said Dr. Shilpi Kushwaha, Senior Scientist at CSMCRI.

That one-nanometer target is not just a small number. At this scale, tiny differences in molecular size and shape start to matter, which is why biology uses channels with near-perfect dimensions to control what passes through. The team drew inspiration from aquaporins, natural protein channels that let water through while blocking many other molecules, and aimed for the same kind of size-based decision-making in a synthetic material.

A quick nap in the middle of the day might do more than fight off drowsiness. A study recently published in the journal NeuroImage reports that a brief afternoon sleep can shift how brain cells connect with one another, making it easier to take in and store new information. The research team, based at the Medical Center – University of Freiburg and the University of Geneva, found that this kind of reset does not necessarily require a full night’s sleep.

The idea is simple: as you move through the day, the brain keeps strengthening communication pathways as it processes sights, ideas, and experiences. That strengthening supports learning, but it can also crowd the system, leaving the brain less flexible for what comes next. In the new work, a short sleep period appeared to dial back that built-up activity and restore the brain’s readiness to learn, which could be especially useful during periods of high workload.

“Our results suggest that even short periods of sleep enhance the brain’s capacity to encode new information,” says study leader Prof. Dr. Christoph Nissen, who performed the study during his time as medical director of the sleep center at the Department of Psychiatry and Psychotherapy at the Medical Center – University of Freiburg, Germany

Certain cancers are extremely difficult to treat, and carcinomas are among the most stubborn. Unlike many other malignancies, these tumors can behave in unusual ways. Some have the ability to shift their identity, taking on characteristics of cells from entirely different organs, including skin. This shape-changing behavior makes them especially hard to target with current therapies. “The tumors are notoriously plastic in their cellular identity,” says Cold Spring Harbor Laboratory (CSHL) Professor Christopher Vakoc. In some cases, this flexibility allows tumors to adapt and survive treatment.

New Studies Reveal Vulnerabilities in Pancreatic and Lung Cancer
Recent research from the Vakoc lab has uncovered important weaknesses in two particularly challenging carcinomas. According to Vakoc, these discoveries may “tee up targets for therapy.”

In a study published in Nature Communications, CSHL scientists identified a protein that controls whether pancreatic cancer cells keep their traditional identity or begin to resemble and behave like skin cells. In separate work reported in Cell Reports, the team determined the crystal structure of another group of proteins that is central to tuft cell lung cancer.

Continuous sleep is a modern habit, not an evolutionary constant, which helps explain why many of us still wake at 3 am and wonder if something's wrong. It might help to know that this is a deeply human experience.

For most of human history, a continuous eight-hour snooze was not the norm. Instead, people commonly slept in two shifts each night, often called a "first sleep" and "second sleep."

Each of these sleeps lasted several hours, separated by a gap of wakefulness for an hour or more in the middle of the night. Historical records from Europe, Africa, Asia, and beyond describe how, after nightfall, families would go to bed early, then wake around midnight for a while before returning to sleep until dawn.

Breaking the night into two parts probably changed how time felt. The quiet interval gave nights a clear middle, which can make long winter evenings feel less continuous and easier to manage.

The midnight interval was not dead time; it was noticed time, which shapes how long nights are experienced.

Some people would get up to tend to chores like stirring the fire or checking on animals. Others stayed in bed to pray or contemplate dreams they'd just had. Letters and diaries from pre-industrial times mention people using the quiet hours to read, write, or even socialise quietly with family or neighbours. Many couples took advantage of this midnight wakefulness for intimacy.

Literature from as far back as ancient Greek poet Homer and Roman poet Virgil contains references to an "hour which terminates the first sleep," indicating how commonplace the two-shift night was.

How we lost the 'second sleep'
The disappearance of the second sleep happened over the past two centuries due to profound societal changes.

Artificial lighting is one of them. In the 1700s and 1800s, first oil lamps, then gas lighting, and eventually electric light, began turning night into more usable waking time. Instead of going to bed shortly after sunset, people started staying up later into the evening under lamplight.

Bacteria have evolved to adapt to all of Earth's most extreme conditions, from scorching heat to temperatures well below zero. Ice caves are just one of the environments hosting a variety of microorganisms that represent a source of genetic diversity that has not yet been studied extensively. Now, researchers in Romania tested antibiotic resistance profiles of a bacterial strain that until recently was hidden in a 5,000-year-old layer of ice of an underground ice cave—and found it could be an opportunity for developing new strategies to prevent the rise of antibiotic resistance and study how resistance naturally evolves and spreads. They reported their discovery in Frontiers in Microbiology.

"The Psychrobacter SC65A.3 bacterial strain isolated from Scarisoara Ice Cave, despite its ancient origin, shows resistance to multiple modern antibiotics and carries over 100 resistance-related genes," said author Dr. Cristina Purcarea, a senior scientist at the Institute of Biology Bucharest of the Romanian Academy. "But it can also inhibit the growth of several major antibiotic-resistant 'superbugs' and showed important enzymatic activities with important biotechnological potential."

Ancient resistance to modern medication
Psychrobacter SC65A.3 is a strain of the genus Psychrobacter, which are bacteria adapted to cold environments. Some species can cause infections in humans or animals. Psychrobacter bacteria have biotechnological potential, but the antibiotic resistance profiles of these bacteria are largely unknown.

"Studying microbes such as Psychrobacter SC65A.3 retrieved from millennia-old cave ice deposits reveals how antibiotic resistance evolved naturally in the environment, long before modern antibiotics were ever used," said Purcarea.

Formed over millions of years, the layered sandstone cliffs of Utah's Zion National Park reveal the climates, conditions, and transformations that shaped the landscape.

Scientists at the University of Oxford have created an advanced technique that allows them to clearly see a crucial but previously hard-to-detect part of lithium-ion battery electrodes. The findings, published today (February 17) in Nature Communications, could improve how battery electrodes are manufactured and lead to faster charging and longer-lasting Li-ion batteries.

The research centers on polymer binders used in the negative electrodes of lithium-ion batteries (anodes). Although these binders account for less than 5% of the electrode’s weight, they play an essential role in keeping the electrode intact. They influence mechanical strength, electrical and ionic conductivity, and overall battery lifespan. Because binders lack distinctive visual features and are present in such small amounts, scientists have struggled to track where they are located inside the electrode. That limitation has made it difficult to fine-tune battery performance, since binder placement directly affects conductivity, structural stability, and durability over time.

Patent Pending Staining Technique Makes Binders Visible
To solve this long-standing challenge, the team developed a patent-pending staining method that attaches traceable silver and bromine markers to widely used cellulose- and latex-based binders in both graphite- and silicon-based anodes. Once tagged, the binders can be detected because they emit characteristic X-rays (measured with energy-dispersive X-ray spectroscopy) or reflect high-energy electrons from the surface (measured with energy-selective backscattered electron imaging). Under an electron microscope, these signals reveal detailed information about where elements are distributed and what the surface structure looks like.

In 2025, planetary scientists reported the detection of long-chain alkanes at concentrations of roughly 30 to 50 parts per billion in the ancient Cumberland mudstone in Gale crater, Mars.

They proposed that the alkanes were derived from thermal decarboxylation of fatty acids during analysis by Curiosity’s Sample Analysis at Mars (SAM) instrument.

In a new study, Dr. Alexander Pavlov from NASA’s Goddard Space Flight Center and his colleagues argue that the measured values are merely a lower limit, because most of the original organic material was likely destroyed by radiation over tens of millions of years.

The Cumberland mudstone may originally have contained between 120 and 7,700 parts per million of long-chain alkanes or their fatty-acid precursors before it was exposed at the surface.

“To reach this conclusion, we combined lab radiation experiments, mathematical modeling, and Curiosity data to ‘rewind the clock’ about 80 million years — the length of time the rock would have been exposed on the Martian surface,” the researchers said.

“This allowed us to estimate how much organic material would have been present before being destroyed by long-term exposure to cosmic radiation: far more than typical non-biological processes could produce.”

The scientists also assessed whether known non-biological processes could explain the unusually high inferred abundance of long-chain alkanes.

According to the study, delivery by meteorites and interplanetary dust particles is insufficient by many orders of magnitude, given the estimated sedimentation rates and the inability of dust particles to penetrate lithified rock.

Atmospheric production of organic haze is also unlikely, because early Mars probably lacked the methane-rich conditions required to generate substantial haze deposition.

The authors also examined hydrothermal processes that can produce hydrocarbons under certain conditions.

While lab experiments show that long-chain organic molecules can form hydrothermally, the mineralogy of the Cumberland mudstone indicates it did not experience the high temperatures associated with such reactions.

The findings suggest a more speculative possibility: that some or all of the original organic material could have been produced by a hypothetical ancient Martian biosphere.

“We agree with Carl Sagan’s claim that extraordinary claims require extraordinary evidence and understand that any purported detection of life on Mars will necessarily be met with intense scrutiny,” the researchers said.

“In addition, in practice with established norms in the field of astrobiology, we note that the certainty of a life detection beyond Earth will require multiple lines of evidence.”

Older adults who are exposed to higher levels of air pollution appear more likely to develop Alzheimer’s disease, according to new research led by Yanling Deng of Emory University.

Alzheimer’s disease is the leading cause of dementia, affecting an estimated 57 million people worldwide. Air pollution has already been identified as a risk factor not only for Alzheimer’s, but also for several chronic conditions, including hypertension, stroke, and depression. These same health problems are also associated with dementia. Until now, however, scientists were unsure whether polluted air increases dementia risk by first contributing to these chronic illnesses, or whether those illnesses simply make the brain more vulnerable to pollution’s effects.

Massive Medicare Study Examines 27.8 Million Older Adults
To investigate, researchers analyzed data from more than 27.8 million U.S. Medicare beneficiaries age 65 and older between 2000 and 2018. They compared long term exposure to air pollution with new diagnoses of Alzheimer’s disease, while also examining whether conditions such as stroke, hypertension, and depression influenced the relationship.

The results showed a clear pattern. Higher exposure to air pollution was linked to a greater risk of developing Alzheimer’s disease. The association was somewhat stronger among individuals who had previously experienced a stroke. In contrast, hypertension and depression did not appear to significantly intensify the pollution-related risk.