Explore the latest insights from top science journals in the Muser Press roundup (July 10, 2026), featuring impactful research on climate change challenges.
In brief:
— Press Release —
Climate change makes marine animals shrink
For the study, the research team analyzed almost 9,000 size changes from fossil, historical and modern analyses. This allowed changes in body size in marine animals over a span of roughly 450 million years to be compared.
How marine animals respond to environmental crises
“Our data show that the decrease in body size is a general response of marine animals to environmental crises,” says Dr. Paulina Nätscher, former researcher at the Chair of Paleoenvironmental Analysis at FAU and lead author of the study. “We observed this phenomenon in very different animal groups, from dwarfism in individual species to a dominance of smaller species across entire communities. It is a clear sign that ecosystems are under stress.”
The changes were particularly prominent during warming phases. “In all environmental crises, whether caused by warming or not, a reduction in body size occurs within communities,” explains her colleague Dr. Kenneth De Baets from the University of Warsaw. “However, what is particularly notable is that crises with pronounced warming lead to markedly stronger and more variable changes directly within species; that is, to genuine dwarfing. On average, these effects are about twice as strong during warming than they are with other crises.”
The link with the rise in temperature is also clearly evident, says Professor Wolfgang Kießling, Chair of Paleoenvironmental Analysis at FAU: “The stronger the temperature rises, the more pronounced the reduction in body size. Earth’s history thus provides a clear warning sign for the future of the oceans.”
Implications for marine ecosystems
The study suggests that the currently observed trend toward smaller fish and invertebrate marine animals is not a short‑term phenomenon, but follows a long‑term pattern. If global warming continues, smaller body sizes in the world’s oceans could increasingly become the norm – with far‑reaching consequences for food chains and fisheries.
Journal Reference:
P.S. Nätscher, K. De Baets, & W. Kiessling, ‘Unique fingerprint of marine ectotherm body size change during hyperthermal crises’, Proceedings of the National Academy of Sciences U.S.A. 123 (26) e2505564123 (2026). DOI: 10.1073/pnas.2505564123
Article Source:
Press Release/Material by Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU)
— Press Release —
As the US recovers from its latest heatwave, a new study warns of an increase in hospitalizations for mental health issues
As the US recovers from its 4 July heatwave, a new study warns of an impending uptick in people attending hospitals for mental health and behavioural disorders, according to the first multi-country study of heatwave-related mental health hospitalization, led by Monash University in Australia.
The study, led by Professors Yuming Guo and Shanshan Li and published in Nature Health, looked at more than 2.6 million warm-season hospitalisations from 852 locations in Brazil, Canada, Chile and New Zealand from 2000 to 2019 – finding that sustained exposure to extreme heat, as experienced in heatwaves, was associated with an increased risk of hospitalization for mental and behavioural disorders.
A heatwave is defined as a period of extremely high ambient temperatures that lasts for several days, during which heat-related disease and death rise substantially.
According to Professor Guo, the association between exposure to a heatwave and hospitalisation for mental and behavioral disorders was more pronounced among older adults and residents of low-population-density areas. “These findings indicate that prolonged extreme heat can acutely increase mental health-related hospital demand and support targeted preparedness during severe heatwaves,” he said.
Read also: Most heat-health plans neglect mental health risks from extreme heat
Professor Li added that climate change “has emerged as a pressing factor influencing mental health on a global scale, with extreme weather events, resource scarcity and ecosystem disruptions amplifying psychological stress and mental health risks.”
“And one noticeable climate-related issue is the increasing frequency and intensity of heatwaves, such as those being experienced in the US and across Europe at the moment,” she said.
Heatwaves may trigger acute exacerbations of mental and behavioural disorders through sleep disruption and physiological stress responses, with heightened vulnerability among individuals with impaired thermoregulation or medication-related heat sensitivity.
Heat-related psychological distress and behavioural changes during heatwaves may further contribute to symptom destabilization and increased hospital admissions.
This study is the first to estimate heatwave-related hospitalization risks and burdens for mental and behavioral disorders across different countries, sexes, ages, GDP per capita, population densities, air-conditioner penetrations, travel time to healthcare facilities and causes of mental health and behavioral disorders.
Journal Reference:
Liu, Y., Xu, Z., Huang, W. et al., ‘Mental health hospitalizations associated with sustained extreme heat in multiple countries’, Nature Health (2026). DOI: 10.1038/s44360-026-00166-2
Article Source:
Press Release/Material by Monash University
— Press Release —
Understanding Earth’s past temperatures
Research at the University of Leeds used a new method of measurement to understand how warm the Earth’s temperature has been over the Phanerozoic period – from around 540 million years ago to the present day.
Studies previously estimated that the planet’s temperature could have reached up to 20 degrees Celsius above preindustrial levels during some geological periods, and maybe even up to 30 degrees above preindustrial in earlier times when the first animals evolved.
But research published in the journal Nature Communications reveals that negative feedback processes (natural stabilising processes like rock weathering) have helped to keep the Earth’s temperature regulated over millions of years, which allowed the biosphere to continue evolving.
The study concludes that the Earth’s past warm periods were more likely to have had past temperatures of around 10 degrees Celsius above preindustrial temperatures – hotter than today but much cooler than previously thought.
Researchers believe these findings could be crucial for understanding the impact of future climate change, as well as exploring biological evolution and extinction, where understanding the heat tolerances of ancient biospheres can help us conserve the present biosphere.
Lead author of the study, Dr Dongyu Zheng from Chengdu University of Technology, conducted the work as a visiting fellow at Leeds. He said: “This study shows how ancient rocks and modern climate simulations can work together to reveal the boundaries of Earth’s long-term climate.
“The evolution and flourishing of life were not sporadic accidents, but were closely linked to Earth’s ability to regulate its climate over geological time.”
Previous studies had used oxygen isotopes in sediments which showed a long-term shift towards lower isotope values, indicating that tropical oceans in the past may have been extremely warm.
Dr Zheng and colleagues instead used the Chemical Index of Alteration (CIA), which measures the depletion in weatherable elements in rock samples and can reveal how sediments have been exposed to warm temperatures in the past. Data used to calculate CIA is widely recorded, resulting in a database of tens of thousands of readings. Using these readings, the researchers were able to reconstruct past global temperatures by combining individual measurements with climate model simulated temperatures in these regions.
Their research also revealed that Earth’s long term climate sensitivity (a measurement of how the Earth’s temperature reacts to increases of carbon dioxide) may be lower than has recently been proposed.
The senior author of the study, Professor Benjamin Mills, Professor of Earth System Evolution at the University of Leeds, said: “The findings suggest that that Earth’s temperature has been tightly regulated over time, and that human-driven warming of 10 degrees Celsius – which is possible if all fossil fuel reserved are burned – would take us to places the Earth may never have been before. How far can we push the planet?
“We shouldn’t be complacent when viewing ancient hot climates that supported diverse ecosystems, and we must understand that they were established extremely slowly, and may not have been as a hot as recently proposed. Earth’s natural regulation systems are slow, and humans must perform our own climate regulation to keep the planet in a habitable range.”
Journal Reference:
Zheng, D., Lipp, A.G., Farnsworth, A. et al., ‘Tight regulation of Earth’s long-term temperature over Phanerozoic time’, Nature Communications 17, 5995 (2026). DOI: 10.1038/s41467-026-72672-6
Article Source:
Press Release/Material by University of Leeds
— Press Release —
Scientists unravel the fast-moving ‘butterfly effect’ of the deep ocean
An international research team, led by the University of Cambridge, found that deep ocean turbulence – the process that distributes heat, nutrients and carbon from the surface to the seafloor and back – affects our lives not on a scale of thousands of years as was previously thought, but within the span of a human lifetime.
However, the tools used to predict these effects and inform policy do not adequately represent this turbulence, or the speed at which it moves. The results are reported in the journal Nature Communications.
The findings come at a time when global ocean research of this kind is at risk. In May, the US National Science Foundation announced the dismantling of the Ocean Observatories Initiative, a $368 million ocean observation network that provides vital oceanographic data worldwide, although the plans were later partially cancelled.
Changing turbulence patterns could affect our climate in tangible ways, which is why this type of ocean monitoring is key: if nutrients are not being pulled from the deep ocean to the surface, it could cause marine food chains to break down, which would in turn cause fisheries to collapse. The way that heat is transferred from the deep ocean to shallower waters and back affects how Arctic and Antarctic ice melts, which affects sea level rise, storm intensity and flooding levels.
Using a combination of previously collected physical and chemical measurements, the researchers identified several fats-moving climatic processes affected by small-scale turbulence, including the distribution of heat, nutrients, and carbon. When compared with how climate models predict how turbulence in the deep ocean will affect life on land, the researchers found these models require significant improvements.
“There is a microphysics of the ocean, similar to cloud physics, that is extremely difficult and expensive to observe, but it governs our lives on human-relevant timescales – from ocean circulation changes to ecosystem dynamics, with implications for fisheries and food security, to coastal flooding and heatwaves,” said lead author Dr Laura Cimoli from Cambridge’s Department of Applied Mathematics and Theoretical Physics (DAMTP). “We need the tools we use to predict these effects to be as accurate as possible, and we found that’s currently not the case.”
“If I think about what matters most on human timescales, it’s three things: marine nutrients and ecosystems, which impact food security; Arctic changes, which have direct geopolitical implications and almost immediately affect extreme weather and flooding in the UK; and mixing of the deep southward flows feeding warm water to Antarctic ice shelves, which drive sea level rise,” said co-author Dr Ali Mashayek from Cambridge’s Department of Earth Sciences.
One of the tracers the researchers used to test the accuracy of climate models was CFC (chlorofluorocarbon) concentration. CFCs were released into the atmosphere in large quantities before being banned in the 1980s under the Montreal Protocol, due to the damage they caused to the ozone layer.
The researchers tracked how far and how fast CFCs have travelled over the past six decades by measuring their concentration at depth. They found some deep waters have carried CFCs all the way from Antarctica to the mid-Pacific and north Indian Ocean in just 40 years. The same waters also carry carbon, oxygen, and heat. As they travel, they mix with other waters, and so turbulence is key to how much tracers, heat, and carbon remain trapped in the deep ocean and on what time scales.
“We’re learning that the deep ocean can exchange carbon, nutrients, heat and pollutants with the atmosphere on timescales relevant to our own lives” said Mashayek.
Another experiment involved injecting dye into the deep ocean at known locations and depths and tracking its movement. In a deep canyon in the Rockall Trough, not far from UK waters, the dye rose as much as 100 metres per day: roughly 10,000 times faster than models predicted.
However, when comparing the CFC, dye, and other observational data with climate models, the team found that the models’ output often deviated significantly from the observational data.
“This shows that climate models are not reliably capturing key effects of deep ocean turbulence,” said co-author Professor Colm-cille Caulfield, also from DAMTP. “If we’re going to make these models more useful for decision-makers, we will need to understand the underlying fundamental physical processes much better, develop better approximations that capture all those processes in computationally efficient ways that can be embedded in climate models straightforwardly, and test and constrain the outputs of the approximations with much more observational data. All aspects of this pipeline are now at risk as science budgets are cut.”
“It used to be that turbulence in the ocean interior was thought of as deep, distant and too slow to matter on human-relevant timescales, but there is increasing evidence that’s not always the case,” said co-author Professor Alberto Naveira Garabato from the University of Southampton. “The deep ocean can interact with the atmosphere on short timescales, and we need reliable tools to help us measure it.”
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The research was supported in part by Schmidt Sciences LLC, the Advanced Research and Invention Agency (ARIA), the Natural Environment Research Council (NERC) and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI). Laura Cimoli is a Bye-Fellow of Murray Edwards College, Cambridge. Ali Mashayek is a Fellow of Peterhouse, Cambridge. Colm-cille Caulfield is a Fellow of Churchill College, Cambridge.
Journal Reference:
Cimoli, L., Mashayek, A., Naveira Garabato, A.C. et al., ‘Climatic reach of small-scale turbulence in the ocean interior’, Nature Communications 17, 5212 (2026). DOI: 10.1038/s41467-026-73809-3
Article Source:
Press Release/Material by University of Cambridge
Featured image credit: Magnific (AI Gen.)
