In recent decades, scientists have clearly demonstrated that chimpanzees, like humans, pass on complex cultures such as tool use from generation to generation. But human culture has become vastly more sophisticated, from the Stone Age to the Space Age, as new advances have been incorporated. Chimpanzee cultures haven’t changed in the same way, which suggests that only humans have the remarkable ability to build more sophisticated cultures over time.

Scientists studying chimpanzees in the wild, however, have disputed this, suggesting that some of chimpanzees’ most complex technologies, in which they use multiple tools in sequence to extract hidden food sources, were probably built on previous knowledge over time.

Tracing genetic links

“As most chimpanzee tools, such as sticks and stems, are perishable, there are few records of their history to confirm this hypothesis — unlike human cases such as the evolution of the wheel or computer technology,” says lead author Cassandra Gunasekaram from the Department of Evolutionary Anthropology at the University of Zurich.

For the new study, a team of anthropologists, primatologists, physicists and geneticists from universities and research institutions in Zurich, St. Andrews, Barcelona, Cambridge, Konstanz and Vienna joined forces to trace genetic links between chimpanzee populations over thousands of years, using new discoveries in genetics to uncover key pieces of chimpanzee cultural history in ways never before imagined.

Early stages of cumulative culture

The authors collected information on markers of genetic similarity — genetic evidence of links between different groups of chimpanzees — as well as a range of foraging behaviors previously reported to be culturally learned, from a total of 35 chimpanzee study sites across Africa. They grouped these behaviors into those that required no tools; those that required simple tools, such as using a leaf sponge to get water from a tree hole; and the most complex behaviors that relied on a toolset.

Trading toolsets across generations

“As an example of such a toolset, chimpanzees in the Congo region first use a strong stick to dig a deep tunnel through hard soil to reach an underground termite nest,” explains Gunasekaram. “Next, they make a ‘fishing’ probe by pulling a long plant stem through their teeth to form a brush-like tip, pressing it into a point and deftly threading it down the tunnel they’ve made. They then pull it out and nibble off any defending termites that have bitten into it.”

“We made the surprising discovery that it is the most complex chimpanzee technologies — the use of entire ‘toolsets’ — that are most strongly linked across now distant populations,” says corresponding author Andrea Migliano, professor of evolutionary anthropology at UZH. “This is exactly what would be predicted if these more advanced technologies were rarely invented and even less likely to be reinvented, and therefore more likely to have been transmitted between groups.”

How female migrations spread innovation

In chimpanzees, it is sexually maturing females, rather than males, who migrate to new communities to avoid inbreeding. In this way, genes are spread between neighboring groups and then further afield over the years, centuries and millennia. The study authors discovered that it would be these same female migrations that could spread any new cultural advances to communities that lacked them.

The study also showed that when both complex toolsets and their simpler versions (i.e., mostly the components of the toolsets) occur at different study sites, the genetic markers indicate that the sites were connected in the past by female migrations. This suggests that the complex versions were built cumulatively by adding to or modifying the simple ones. “These groundbreaking discoveries provide a new way to demonstrate that chimpanzees have a cumulative culture, albeit at an early stage of development,” Migliano adds.

The winter holiday festivities have come and gone. But after the inevitable baking, entertaining, giving, and receiving associated with the season, do you find you have more than a few leftover aluminum pie pans?

The good news, as you may already know, is that aluminum pans are recyclable. But before you toss them in the recycling bin, you might want to see if you can get more use out of them. Here are a few reuse and upcycling ideas — from the practical to the crafty — for those old aluminum pans.

1. Feed the Birds — and Squirrels

Birds, squirrels, and other wildlife tend to have trouble finding food during the chilly winter months. Give back to the friendly critters in your yard by creating a low-cost feeder from an aluminum pie pan.

Simply place the pan on a flat surface outdoors, weigh it down with a rock from the yard and fill it with the birdseed of your choice. Your feathered friends will thank you — perhaps with a chirp or two — if the squirrels don’t eat it all first.

2. Use Pie Pans for Crafts

Aluminum pans are perfect for crafting, especially with young children. Use them as palettes for paints. Or store your beads, glitters, and glues in them while working on a project with the kids.

After craft time, simply wash your pan well with warm water and dry it. Then, you can either save it for future crafts or place it in the recycling bin.

3. Deck the Halls

If you want to get a little rustic with your decorating, take a lesson from the ages. In the past, people crafted holiday ornaments from old cans and scrap tinplate. With a bit of work and creativity, you can craft your own traditional-style ornaments. All you’ll need is aluminum pans and a few basic tools to get the job done.

4. Keep Candles From Making a Mess

Pillar candles tend to drip, and a big mess definitely ruins the ambiance. Save your surfaces by placing an aluminum pie pan under your candles before lighting them.

If you’re concerned that an aluminum pan may clash with your décor, simply cut out the bottom using heavy-duty scissors and toss the sides in the recycling bin. The flat aluminum circle will be less conspicuous but will still protect your tables from dripping wax.

5. Feed Fido On the Go

Since they’re lightweight but fairly sturdy, aluminum pie pans are perfect for on-the-go pet dishes.

Save them with your outdoor gear and use them for food and water bowls on your next camping trip, picnic, or beach excursion.

6. Make Picture Frames

SFGate.com contributor Mary Love suggests using pie pans as alternative picture frames or frames for displaying your child’s art. Simply paint the plate with craft paint, cut a circle from a photo, and glue it into place. Glue a magnet on the back to display the picture on your fridge.

7. Reduce the Mess While Cooking

Networx.com writer Sayward Rebhal suggests using old pie pans as baskets for grilling veggies. To prevent your vegetables from falling into the coals, simply poke a few holes in aluminum pan, fill it with your veggies, and put the whole thing on the grill.

An aluminum pan with small holes is also great for reducing messes while frying foods on the stove. If you’re dealing with a lot of oil spatter, simply place the pie pan over your food in the frying pan to protect yourself and your kitchen from hot cooking oil.

8. Cookout Tools

Try using old aluminum pans to protect your hands when toasting food on a stick over a fire during an outdoor cookout.

Simply punch two holes in opposite sides of a pan. Then slide the stick you’ll use for toasting your marshmallows or hot dogs through the holes. The aluminum will be at one end of the stick and you will spear your food on the other end. The aluminum creates a heat shield for your hand while you hold your food over the fire or coals.

9. Garden Planter

Although this isn’t a reuse idea for pie-sized pans, we thought we’d include it as you may also have some larger aluminum pans you’d like to reuse before you recycle them.

The contributors at ThriftyFun.org suggest using an old aluminum roasting or loaf pan as a planter for the garden. These larger pans can hold multiple seed pots when you’re starting your seedlings in the spring. They’ll hold water, and with their higher edges, the pans can keep your seedlings upright and stable.

Editor’s note: Originally published on November 27, 2013, this article was updated in November 2024.

Now, researchers at the Broad Institute of MIT and Harvard and Massachusetts General Hospital have analyzed the entire mouse intestine, mapping gene expression and cell states and location in the healthy gut and in response to perturbations such as inflammation. They identified tight regulation of cell types and states in different regions of the organ, as well as a unique segment of the colon that is controlled by immune signals. The findings, which appear in Nature, reveal the surprising adaptability and resilience of the intestine to perturbations and highlight the importance of considering how cell processes are regulated and vary across different parts of a tissue or organ.

“The intestine and in particular the colon has been studied for decades but it hasn’t been characterized in this way before, and that both forces us to reevaluate many different studies and opens up a window for future research,” said Toufic Mayassi, a co-first author on the study along with Chenhao Li. Mayassi and Li are postdoctoral researchers in the lab of Ramnik Xavier, who is a core institute member at the Broad, member of the Center for Computational and Integrative Biology at Massachusetts General Hospital (MGH), and senior author of the study.

“This work illustrates that you really have to integrate the spatial relationships governing a given organ into your thinking, and we hope our study provides a platform and framework that helps put both previous and future discoveries in context,” Mayassi said.

Xavier is the director of Broad’s Immunology Program, as well as the Kurt J. Isselbacher Professor of Medicine at Harvard Medical School, director of the Center for Computational and Integrative Biology and member of the Department of Molecular Biology at MGH, and co-director of the Center for Microbiome Informatics and Therapeutics at MIT.

“We’ve built a blueprint of the entire gut, and that’s a remarkable achievement,” said Xavier. “We now have a way of studying the whole organ, examining the effect of genetic variants and immune responses associated with diet, the microbiome, and gastrointestinal disease, and designing many other experiments.”

Mapping the intestine

Many previous studies of the gut looked at cells or organ-like assemblies of cells in a dish. While such approaches provide a controlled environment to study the function of specific genetic variants involved in disease, they don’t illustrate how cells from different parts of an intact organ interact to bring about disease.

In 2021, Mayassi, who spent his PhD studying immune responses in the intestine, teamed up with Li, a computational biologist, to build a comprehensive map of gene expression across the entire mouse small intestine and colon using spatial transcriptomics and computational approaches.

To the researchers’ surprise, the spatial composition of the intestine — the relative location of various cell types and the genes they express — remained relatively stable when certain factors changed. It stayed the same in animals with and without gut microbiota and in tissue collected at night or during the day, suggesting that neither the microbiome nor circadian rhythms impacted the spatial landscape.

The intestine also showed signs of resilience. When Mayassi treated the animals with a molecule known to induce inflammation, gene expression and cell spatial distribution changed but showed signs of returning to normal a month later, and had almost entirely recovered by three months. The findings suggest that the gut’s ability to bounce back from changes brought about by inflammation could be critical to intestinal health and function.

“As a computational biologist, it is exciting to be involved in generating and exploring such a unique dataset,” Li said. “It opens the door to developing tools for analyzing spatial data and informs the design of future studies on the small and large intestine.”

Immune control

Though the intestine was stable to many influences, unique niches within the organ were affected by the gut microbiota and showed signs of adaptation. Mice that had a normal microbiome expressed unique genes in a specific region of the colon compared to germ-free mice. Using single-cell RNA sequencing, the authors found that the changes occurred in three structural cell types. In particular, goblet cells — cup-shaped cells that secrete mucus — expressed those genes only in the presence of ILC2s, a kind of immune cell.

Next, the researchers plan to apply their method to study how other factors including sex, diet, food allergies, and genetic risk factors for conditions such as inflammatory bowel disease impact the intestine’s spatial landscape. They also hope to elucidate the extent to which the findings in mice correlate with spatial control in the human gut.

This discovery has far-reaching implications for our understanding of past climate variability and future climate change. However, lead author and junior professor Dr Sebastian Sippel from Leipzig University stresses that the new findings do not affect the quantification of the global warming relative to 1850-1900 and the human contribution to that warming: the land and ocean temperatures of the 19th century (1850-1900), before the onset of the cold period, provide a physically very consistent picture of temperature changes up to the present day. Nevertheless, correcting this cold period could increase confidence in the amount of observed warming, changing what we know about historical climate variability and improve the quality of future climate models.

Understanding global temperature trends is crucial for climate research. Dr Sebastian Sippel, Junior Professor for Climate Attribution at Leipzig University, worked with international scientists to reconstruct the global mean temperature from historical climate data like a jigsaw puzzle — including historical land and ocean measurements and palaeoclimatic analyses. When comparing land and ocean, Sippel noticed a systematic deviation: at the beginning of the 20th century, ocean temperatures were lower than in previous decades, while over land air temperatures remained relatively constant. This outcome is not consistent with physical theory and climate models.

New explanations for past phenomena

Using many different lines of evidence, the new study shows that reconstructions of the global mean temperature from ocean surface data for this period are too cold: on average about 0.26 degrees Celsius colder than seen in land-based reconstructions. This discrepancy is greater than what would be possible under natural climate variability. “Our latest findings do not change the long-term warming since 1850. However, we can now better understand historical climate change and climate variability,” says junior professor Dr Sebastian Sippel. For example, the reasons for the early 20th century warming period between 1900 and 1950 have never been fully understood. If the ocean temperatures are corrected, the warming trend of the early 20th century is weaker. “The discrepancies between the climate models and the observed temperature trend at the beginning of the 20th century are mainly due to an incomplete understanding of the observations, rather than incomplete climate models or natural climate variability. There are well-established approaches to account for the effects of changing measurement methods on ocean surface temperature measurements. The new research shows that in the early 20th century these methods don’t properly account for very rapidly changing differences in the way the observations were made. Our new understanding confirms the climate models and shows even more clearly the human impact since pre-industrial times,” says co-author Professor Reto Knutti, Professor for Climate Physics at ETH Zurich.

A multidimensional approach

The study itself offers indications that the cause of the ocean cold anomaly could lie in insufficiently documented information about the measurement techniques used at that time. Before the Second World War, ocean temperatures were mainly measured with buckets on ships, but the method of measurement and the composition of ship fleets changed from decade to decade, making it much more difficult to correct for systematic measurement errors. The authors of the study therefore recommend a variety of approaches to data processing and analysis: “Our methodological approach emphasises the need to continuously rescue and digitise historical climate data and compare it with independent data. At the same time, very different assumptions regarding systematic adjustments of early climate data should be tested, as the observational data are of central importance as a basis for climate understanding and modelling,” says Sippel.

Thousands of whales are injured or killed each year after being struck by ships, particularly the large container vessels that ferry 80% of the world’s traded goods across the oceans. Collisions are the leading cause of death worldwide for large whale species. Yet global data on ship strikes of whales are hard to come by — impeding efforts to protect vulnerable whale species. A new study led by the University of Washington has for the first time quantified the risk for whale-ship collisions worldwide for four geographically widespread ocean giants that are threatened by shipping: blue, fin, humpback and sperm whales.

In the paper, published online Nov. 21 in Science, researchers report that global shipping traffic overlaps with about 92% of these whale species’ ranges.

“This translates to ships traveling thousands of times the distance to the moon and back within these species’ ranges each and every year, and this problem is only projected to increase as global trade grows in the coming decades,” said senior author Briana Abrahms, a UW assistant professor of biology and researcher with the Center for Ecosystem Sentinels.

“Whale-ship collisions have typically only been studied at a local or regional level — like off the east and west coasts of the continental U.S., and patterns of risk remain unknown for large areas,” said lead author Anna Nisi, a UW postdoctoral researcher in the Center for Ecosystem Sentinels. “Our study is an attempt to fill those knowledge gaps and understand the risk of ship strikes on a global level. It’s important to understand where these collisions are likely to occur because there are some really simple interventions that can substantially reduce collision risk.”

The team found that only about 7% of areas at highest risk for whale-ship collisions have any measures in place to protect whales from this threat. These measures include speed reductions, both mandatory and voluntary, for ships crossing waters that overlap with whale migration or feeding areas.

“As much as we found cause for concern, we also found some big silver linings,” said Abrahms. “For example, implementing management measures across only an additional 2.6% of the ocean’s surface would protect all of the highest-risk collision hotspots we identified.”

“Trade-offs between industrial and conservation outcomes are not usually this optimal,” said co-author Heather Welch, a research scientist with the National Oceanic and Atmospheric Administration and the University of California, Santa Cruz. “Oftentimes industrial activities must be greatly limited to achieve conservation goals, or vice versa. In this case, there is a potentially large conservation benefit to whales for not much cost to the shipping industry.”

Those highest-risk areas for the four while species included in the study lie largely along coastal areas in the Mediterranean, portions of the Americas, southern Africa and parts of Asia.

The international team behind the study, which includes researchers across five continents, looked at the waters where these four whale species live, feed and migrate by pooling data from disparate sources — including government surveys, sightings by members of the public, tagging studies and even whaling records. The team collected some 435,000 unique whale sightings. They then combined this novel database with information on the courses of 176,000 cargo vessels from 2017 to 2022 — tracked by each ship’s automatic identification system and processed using an algorithm from Global Fishing Watch — to identify where whales and ships are most likely to meet.

The study uncovered regions already known to be high-risk areas for ship strikes: North America’s Pacific coast, Panama, the Arabian Sea, Sri Lanka, the Canary Islands and the Mediterranean Sea. But it also identified understudied regions at high risk for whale-ship collisions, including southern Africa; South America along the coasts of Brazil, Chile, Peru and Ecuador; the Azores; and East Asia off the coasts of China, Japan and South Korea.

The team found that mandatory measures to reduce whale-ship collisions were very rare, overlapping just 0.54% of blue whale hotspots and 0.27% of humpback hotspots, and not overlapping any fin or sperm whale hotspots. Though many collision hotspots fell within marine protected areas, these preserves often lack speed limits for vessels, as they were largely established to curb fishing and industrial pollution.

For all four species the vast majority of hotpots for whale-ship strikes — more than 95% — hugged coastlines, falling within a nation’s exclusive economic zone. That means that each country could implement its own protection measures in coordination with the U.N.’s International Maritime Organization.

“From the standpoint of conservation, the fact that most high-risk areas lie within exclusive economic zones is actually encouraging,” said Nisi. “It means individual countries have the ability to protect the riskiest areas.”

Of the limited measures now in place, most are along the Pacific coast of North America and in the Mediterranean Sea. In addition to speed reduction, other options to reduce whale-ship strikes include changing vessel routings away from where whales are located, or creating alert systems to notify authorities and mariners when whales are nearby.

“Lowering vessel speed in hotspots also carries additional benefits, such as reducing underwater noise pollution, reducing greenhouse gas emissions, and cutting air pollution, which helps people living in coastal areas,” said Nisi.

The authors hope their global study could spur local or regional research to map out the hotspot zones in finer detail, inform advocacy efforts and consider the impact of climate change, which will change both whale and ship distributions as sea ice melts and ecosystems shift.

“Protecting whales from the impact of ship strikes is a huge global challenge. We’ve seen the benefits of slowing ships down at local scales through programs like ‘Blue Whales Blue Skies’ in California. Scaling up such programs will require a concerted effort by conservation organizations, governments and shipping companies,” said co-author Jono Wilson, director of ocean science at the California Chapter of The Nature Conservancy, which helped identify the need for this study and secured its funding. “Whales play a critical role in marine ecosystems. Through this study we have measurable insights into ship-collision hotspots and risk and where we need to focus to make the most impact.”

Co-authors on the study are Stephanie Brodie, a research scientist with the Commonwealth Scientific and Industrial Research Organisation in Australia; research scientists Callie Leiphardt and Rachel Rhodes, and professor Douglas McCauley, all at the University of California, Santa Barbara; Elliott Hazen, research ecologist with NOAA’s Southwest Fisheries Science Center; Jessica Redfern, associate vice president, Anderson Cabot Center for Ocean Life, New England Aquarium; the UW’s Trevor Branch, professor of aquatic and fishery sciences, and Sue Moore, a research scientist with the Center for Ecosystem Sentinels; André Barreto, professor at the Universidade do Vale do Itajaí in Brazil; senior research biologist John Calambokidis with the Cascadia Research Collective; data scientist Tyler Clavelle, chief scientist David Kroodsma and senior manager Tim White with Global Fishing Watch; research scientists Lauren Dares and Chloe Robinson with Ocean Wise; Asha de Vos with Oceanswell in Sri Lanka and the University of Western Australia; Shane Gero with Carleton University; biologist Jennifer Jackson with the British Antarctic Survey; Robert Kenney, emeritus research scientist with the University of Rhode Island; Russell Leaper with the International Fund for Animal Welfare; Ekaterina Ovsyanikova at the University of Queensland; and Simone Panigada with the Tethys Research Institute in Italy.

The research was funded by The Nature Conservancy, NOAA, the Benioff Ocean Science Laboratory, the National Marine Fisheries Service, Oceankind, Bloomberg Philanthropy, Heritage Expeditions, Ocean Park Hong Kong, National Geographic, NEID Global and the Schmidt Foundation.

The United Nations have introduced the term “triple planetary crisis” to describe the interlinked global crises of climate change, biodiversity loss and environmental pollution. The UN is using this term to highlight the interdependence and mutual impact of these crises on ecosystems, societies and economies. However, while the contribution of plastics on environmental pollution appears to be well researched, biodiversity and climate change have received comparatively little attention. “Scientific understanding of the interactions of these crises with regard to plastics is currently patchy and unevenly distributed,” concludes author and UFZ hydrogeologist Dr Christian Schmidt.

The UFZ researchers operate over a wide range of disciplines from hydrology, toxicology, microbiology and environmental chemistry to social sciences and are part of the UFZ’s Microplastics Competence Cluster. They evaluated more than 19,000 scientific studies in preparing this article. The findings are very clear: 17,463 of the evaluated studies address the negative impacts of plastics and associated chemicals on environmental pollution, only 1,279 consider the impacts on climate change and a scant 652 focus on the impacts on biodiversity. “There is an extremely divergent drift in the available knowledge,” summarizes Prof Annika Jahnke, author and UFZ environmental chemist.

A comprehensive knowledge base is available for environmental pollution, particularly concerning the plastics life cycle. Since the 1950s, approximately 9,200 million tons of plastics have been produced around the world. Of this, 2,900 million tons are currently in use, comprising 2,700 million tons of primary plastics and roughly 200 million tons of recycled material. 5,300 million tons have ended up in landfills and 1000 million tons have been incinerated. It is also known that between 1,750 and 2,500 million tons are considered “mismanaged,” meaning that they can leak into the environment in an unplanned manner. The hazards that plastic-associated chemicals pose to humans and environmental organisms and the impact of plastics on oceans, soils and freshwater ecosystems are also regarded as well researched. However, going further into detail reveals knowledge deficits here as well, which in turn correspond to research gaps: How are plastics in the environment transported further by wind and water? How much plastics reach the oceans? Where do plastics accumulate in the environment? What are the effects of UV radiation, temperature differences or mechanical stress on plastics and the chemicals they contain?

Furthermore, only a paucity of studies deal with the effects of plastics on the atmosphere and the cryosphere, which is that part of the Earth’s surface where water is present as snow or ice. Nanoplastics have also generally been the subject of less research than microplastics. There are significantly more studies on microplastics, as the particles are larger and could therefore be studied by a large number of institutions for some time. The chemical composition of the plastics is also largely unknown, as they contain many added chemicals in addition to the polymer. Examples of these are UV stabilizers, plasticizers or associated processing aids that can be used to facilitate processing of the plastics or to lend them specific desired properties. To date, roughly 640 million tons of additive chemicals have been added to plastic products. “But little is known about how they are released and what consequences they have for people and the environment,” explains Annika Jahnke.

Research on the effects of plastics on climate change is also limited. For example, there is the question of the extent to which greenhouse gas emissions are caused by plastics production, the extent to which plastics affect biogeochemical cycles in the global oceans or how plastics change the albedo, i.e. how much solar radiation is reflected back from the earth’s surface. Similarly few studies have been published on the effects of plastic pollution on biodiversity. There are a few studies, such as on the toxicity of plastics, changes in habitats and ecosystems and rafting of species. “We aim to shift the focus away from viewing plastics as merely a waste problem Not only do plastics cause a disposal and waste management problem, but the entire life cycle must be considered, starting from the extraction of raw materials,” says Christian Schmidt. Plastics also contribute to exacerbation of climate change and biodiversity loss through various mechanisms. Environmental pollution, climate change and biodiversity loss must therefore be considered comprehensively. “We need a broader perspective.”

The UFZ researchers therefore see the need for a strongly overarching focus on international regulations to achieve the necessary shift in perspective towards comprehensive global solutions. “We now know that plastics contain roughly 16,000 chemicals. Of these, it is known that over 4,200 are persistent in the environment, accumulate in living organisms, are transported over long distances or pose a potential hazard,” says Annika Jahnke. Current regulations cover only a very few of these chemicals. Many of these substances could be replaced by less problematic ones that fulfil the same function. Together with UFZ ecotoxicologist Dr Dana Kühnel and as part of the network known as the “Scientists’ Coalition for an Effective Plastics Treaty,” Annika Jahnke intends to contribute recommendations such as these to the negotiations on the global UN plastics treaty, which will be conducted in Busan (South Korea) from 25 November to 1 December. In the final meeting, the international community plans to adopt a global agreement with objectives including reducing the production of new plastics and reducing hazardous plastics chemicals. “Because of the broad impacts of plastics, it is important to also harmonise future agreements with legislation protecting the climate and biodiversity. This necessitates the regulation of plastics and associated chemicals,” says Dana Kühnel.

Mortality attributable to air pollution and extreme temperatures is a major concern, and it is expected to heighten in the future. In a new study led by the Max Planck Institute for Chemistry, an international research team found that, under the most probable projection, annual mortality rates linked to air pollution and extreme temperatures could reach 30 million by the end of the century. The research, based on advanced numerical simulations, suggests a concerning trend: pollution-related deaths are expected to increase five-fold, while temperature-related mortality could rise seven-fold, posing a more critical health risk than air pollution for at least 20% of the world’s population.

The researchers base their calculations on projections from 2000 to 2090, analyzed in ten-year intervals. “In 2000, around 1.6 million people died each year due to extreme temperatures, both cold and heat. By the end of the century, in the most probable scenario, this figure climbs to 10.8 million, roughly a seven-fold increase. For air pollution, annual deaths in 2000 were about 4.1 million. By the century’s close, this number rises to 19.5 million, a five-fold increase,” explains Dr. Andrea Pozzer, group leader at the Max Planck Institute for Chemistry in Mainz and adjunct associate professor at The Cyprus Institute in Nicosia, Cyprus.

The study shows significant regional differences in future mortality rates. South and East Asia are expected to face the strongest increases, driven by aging of the population, with air pollution still playing a major role. In contrast, in high-income regions — such as Western Europe, North America, Australasia, and Asia Pacific — deaths related to extreme temperatures are expected to surpass those caused by air pollution. In some countries within these regions, such as the United States, England, France, Japan and New Zealand, this shift is already occurring. The disparity is likely to grow, with extreme temperatures becoming a more significant health risk than air pollution also in countries of Central and Eastern Europe (e.g., Poland and Romania) and parts of South America (e.g., Argentina and Chile).

By the end of the century, temperature-related health risks are expected to outweigh those linked to air pollution for a fifth of the world’s population, underscoring the urgent need for comprehensive actions to mitigate this growing public health risk.

“Climate change is not just an environmental issue; it is a direct threat to public health,” says Andrea Pozzer. “These findings highlight the critical importance of implementing decisive mitigation measures now to prevent future loss of life,” adds Jean Sciare, director of the Climate and Atmosphere Research Center (CARE-C) of The Cyprus Institute, key contributor to the study.