Real-world geoengineering experiments revealed by UK agency
Getting this 'critical missing scientific data' is vital with the Earth nearing several catastrophic climate tipping points, said the Advanced Research and Invention Agency (Aria), the government agency backing the plan. If demonstrated to be safe, geoengineering could temporarily cool the planet and give more time to tackle the root cause of the climate crisis: the burning of fossil fuels.
The experiments will be small-scale and rigorously assessed before going ahead, Aria said. Other projects in the £56.8m programme will model the impacts of geoengineering on the climate and research how it could be governed internationally.
Geoengineering is controversial, with some scientists calling it a 'dangerous distraction' from cutting emissions and concerned about unintended climate impacts. Some previously planned outdoor experiments have been cancelled after strong opposition.
However, given the failure of the world to stop emissions rising to date, and the recent run of record hot years, backers of solar geoengineering say researching the technology is vital in case an emergency brake is needed. The Aria programme, along with another £10m project, makes the UK one of the biggest funders of geoengineering research in the world.
'Decarbonisation is the first and best chance of avoiding these tipping points,' said Prof Mark Symes, the programme director at Aria. 'But the current trajectory puts us in danger of triggering some tipping points, regardless of what happens with net zero, so we do need to think about what we might do in that eventuality.
'The point of the programme is to explore and research as transparently as possible whether any of the proposed cooling approaches could ever be used safely,' he said. 'Life in the UK could become very difficult if any of these tipping points were triggered.'
Ilan Gur, Aria's CEO, said: 'If science can show us that an elegantly designed spray of seawater can protect and preserve the incredible biodiversity of the Great Barrier Reef, isn't that something we want to understand?'
The announcement was criticised by Prof Raymond Pierrehumbert at the University of Oxford: 'Solar geoengineering has enormous and troubling implications for global society. The UK funding sets a dangerous precedent for other governments to jump on the bandwagon [and] it is the height of folly to open the door to field experiments in the absence of any national or international governance.'
Mary Church, at the Center for International Environmental Law, said: 'Solar geoengineering is inherently unpredictable and risks breaking further an already broken climate system. Conducting small-scale experiments risks normalising highly controversial theories and accelerating technological development, creating a slippery slope toward full-scale deployment.'
Most geoengineering proposals aim to block sunlight reaching and heating the Earth's surface. However, solar radiation management (SRM) has the potential for serious unintended consequences, such as shifting rains vital to food production. Some private companies are already working on geoengineering; that makes building the scientific evidence base even more important, Gur said.
The Aria-funded experiments include sending a weather balloon into the stratosphere above the US or UK. Milligram samples of non-toxic mineral dust will be exposed to the high-altitude conditions and then recovered to assess how the particles' properties change with time.
Another three experiments will test how seawater sprays or electrical charges delivered by drones can seed tiny water droplets, making clouds over the oceans reflect more sunlight. One will expand current work over the Great Barrier Reef, which is in crisis because of global heating, and may reach 100sq km in scale, while another will take place on the UK coast.
A fifth experiment will involve pumping water on to sea ice in Canada in winter, reaching up to one 1 sq km in scale. The water will freeze and preserve the ice sheet for longer in summer. Bright white ice reflects far more sunlight than the dark ocean revealed when sea ice is lost to warming waters.
There will be an environmental impact assessment made public before any outdoor experiments take place and local communities will have been consulted. There is also an independent oversight committee as part of the approval process, Aria said, chaired by the leading climate scientist Prof Piers Forster and including members from India and Ghana.
The Aria programme will also assess space reflectors, which are sunshades placed into orbit, using modelling to determine their feasibility. 'This is the most speculative of all the approaches we're funding,' said Symes. Volcanic eruptions naturally inject particles into the atmosphere and another project will fly drones through the plumes to measure the particles' effects.
Seven modelling teams will investigate the impacts of geoengineering on climate and ecosystems, especially in developing countries, where about 85% of the world's population lives. There will be a further five teams working on ethics and governance to explore the wider societal implications of geoengineering, such as how any future deployment should be agreed and managed.
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Newsweek
12 hours ago
- Newsweek
The New Hunt for Red October: How NATO Keeps Up With Russian Submarines
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Aerial view of the Nato Alliance reserach vessel Aerial view of the Nato Alliance reserach vessel Credits Clément Gargoullaud - Kraken Films Deep in the Arctic, on board NATO's only research vessel, green bars of data move across screens as computers whir, the noise occasionally rising in pitch. To the untrained eye, it all means little. But to NATO's lone scientific unit on board the NRV Alliance, it is a glimpse into how the rapidly changing Arctic could force the alliance to switch how it detects objects—and threats—lurking beneath the waves. One of these threats, and one notoriously hard to pick up, is Russian submarines. Climate change is making the task of finding them even more difficult. As the planet heats up, fresh water is seeping into the Arctic Ocean as the sea ice and the permafrost melts, while warmer waters from the Atlantic bleed in from the south. "Whereas in the past, we would have thought of the Arctic Ocean as a frozen desert, now, increasingly, it's being thought of as open water at some parts of the summer season," Klaus Dodds, a professor at the U.K.'s Royal Holloway, University of London, told Newsweek on board the vessel. "It's an ocean literally undergoing state change." That change in temperature and salinity—or levels of salt—has a heavy hand in influencing how sound moves in water. But knowing how sound travels under the waves is key for picking up threats the alliance otherwise wouldn't spot. This pool photograph distributed by Russian state agency Sputnik shows the new Krasnoyarsk nuclear submarine during a flag-rising ceremony led by Russia's President at the Arctic port of Severodvinsk on December 11, 2023. This pool photograph distributed by Russian state agency Sputnik shows the new Krasnoyarsk nuclear submarine during a flag-rising ceremony led by Russia's President at the Arctic port of Severodvinsk on December 11, 2023. KIRILL IODAS/POOL/AFP/Getty "When you talk about detecting, tracking, identifying submarines, this is something where you can build all the technology you want," the expedition's chief scientist, Gaultier Real, told Newsweek. But "if you don't know the environment in which you are deploying that, in which you're operating that, you're missing something." NATO's Nordic-Recognized Environmental Picture 2025 The Arctic region is made up of the Arctic Ocean—much of which is crusted with ice—and a collection of seas that are generally ice-free and much easier for ships to navigate, like the Barents Sea north of Norway and western Russia, or the northernmost swathes of the Atlantic. All these waters feature high up on the strategic priority lists of the eight states with Arctic territory, and, increasingly, further flung nations. Moscow has a grip on roughly 50 percent of the Arctic coastline. The seven other states with territory in the Arctic Circle include Canada, the U.S. and Norway, all of which are NATO members. The alliance, while keeping one eye on the Arctic Ocean, is typically more concerned about what Russia—and increasingly China—are doing in the ice-free waters of the slightly more southern seas. This is why the NATO scientists set sail on the NRV Alliance from the northern Norwegian city of Tromsø in early July, heading north toward Svalbard and around the Greenland Sea. Many months of work went into scrutinizing where the Arctic ice would be, pulling data from satellites, camera-rigged drones and an experimental radar to map out the best places to drop buoys. Each of these buoys carried hydrophones—microphones that record sound underwater—to pick up acoustic signals sent out from the NATO ship. The scientists would then know which signals to watch out for on the recorders after they bounce off the ice. Robotician working in the lab collecting datas from a previous sound recording. Robotician working in the lab collecting datas from a previous sound recording. Credits Clément Gargoullaud - Kraken Films A smaller boat would break away from the Alliance, dropping the buoys a few miles away from the main ship. The buoys drifted for hours or days before the scientists went back in search of their equipment, with their fingers crossed the hydrophones and their data were floating close by and intact. The signals sent from the NATO ship, however, were low power—and deliberately so. One reason is to protect the wildlife but another, said Real, is that stealth objects would keep as low a profile as possible. "Both from the scientific and the defense point of view, this is a project that we think is extremely important," Real said. "The fact that now this is an area in the world where everything is changing so fast makes it a fantastic playground for science, but also an area of huge strategical importance." The data from the experiments can be pieced together to create a model of how sound from any source travels in the Arctic waters, essentially identifying which sounds are emitted by different objects. NATO militaries can then use this model in their shadowing of Russian submarines as well as have a better idea of how to hide their own submarines from Moscow's surveillance. "We work for the safety, security, of the nations of the alliance, and what we provide to them is our research capability and how this can be translated to operational scenarios," Real said. "We can check with the experiment that we are doing that the models, that the way of operating the sonars is still efficient." "It probably isn't," he added. "It means that we need to adapt the tools that we have." Russia's Submarines During the Cold War, there was a "huge interest" in research that delved into sea ice, and how it could blur views of stealthy objects like submarines, Dodds said. There has also long been a focus on how salinity can toy with acoustics, he added. Russia's Pacific Fleet submarines parade off the port city of Vladivostok during the Navy Day celebrations on July 30, 2023. Russia's Pacific Fleet submarines parade off the port city of Vladivostok during the Navy Day celebrations on July 30, 2023. PAVEL KOROLYOV/AFP/Getty The same is true today. NATO has multiple ways of tracking Russian President Vladimir Putin's submarines, from using its own submarines to flying aircraft designed to hunt vessels in deep water. There are also cables zigzagging along the ocean floor and sensors that can listen in to what passes close by. But there's a common denominator. "I would say everything we do," retired U.S. Air Force General Glen VanHerck told Newsweek, "would be acoustic in nature." Until recently, VanHerck served as the commander of the U.S. Northern Command and the North American Aerospace Defense Command, or NORAD. The joint American and Canadian command oversees both states' Arctic operations. NATO nations can—and do—use other types of equipment, like magnetic anomaly detectors, infrared sensors or radar, said Sidharth Kaushal, a senior research fellow at the influential British think tank the Royal United Services Institute. But "acoustic sensors are by far the most effective way of picking up a submarine." "It's extremely important for NATO countries to be able to know where the Russian submarines are," said Katarzyna Zysk, a professor of international relations and contemporary history at the Norwegian Institute for Defence Studies, closely linked to the Norwegian armed forces. Moscow has always been keen to slip away from NATO surveillance, Zysk told Newsweek. For Russia, sliding its submarines out of NATO's sight is a familiar game—and one it knows how to play well. "I would hope, or I would wish, I could say that we always track Russian submarines," Major General Gjert Lage Dyndal, the deputy commander of the Norwegian Joint Headquarters, told Newsweek, speaking from the city of Bodø to the southwest of Tromsø. "But, of course, that is not the case." "Russian submarines are quite capable, quite quiet, and a challenge to Western nations to track globally, but also in the Arctic," VanHerck said. "They're not as challenging to track, sometimes, as they would be if they get into the open ocean, such as the Atlantic, where they are quieter, but they are certainly a challenge for us in the Arctic." A big part of Russia's submarine strategy is to skulk under the ice, able to threaten NATO with a preemptive attack or powerful retaliation, or simply the possibility they could transit under the ice to pop up close to NATO members' coastlines with highly destructive weapons ready to launch. "It's really hard to detect a submarine that is hiding under the ice," Zysk said. NATO Alliance research vessel docked in Gdynia Harbor, Poland NATO Alliance research vessel docked in Gdynia Harbor, Poland Credits Clément Gargoullaud - Kraken Films Russia has for years test-fired advanced missiles from submerged nuclear-powered ballistic missile submarines in the Arctic. Some reports have even indicated Russia launched a missile that punched through ice at the North Pole. Russia's exact strategy on how and when it breaks through the ice is hard to discern. The Russian feeling has long been that the ice could be Moscow's friend. "There was a belief among Russian military, or really, more Soviet even, military strategists, that because of the icy conditions, NATO ships couldn't really get too far into the Arctic," said Dmitry Gorenburg, a senior research scientist focusing on the Russian military with CNA, a U.S.-based think tank. Now, although Russia still has a good few strategies up its sleeve—like hiding out in the deepest waters—Moscow may be feeling more exposed than ever in areas where it had long leaned on ice to fend off attention from its adversaries, particularly around its smaller bases. The ice is no longer judged to be enough protection, Gorenburg told Newsweek. "That's why you see a lot more positioning of coastal defense batteries [and] maritime patrol aircraft." Climate Change and Trade The Arctic, for the Kremlin, isn't just about defense. It's also about lucrative resources, an opening up of once-untraversable trade routes to commercial traffic and closer ties with China, a self-proclaimed "near-Arctic state" only upping its presence in the region. "One of Russia's major objectives has been to turn the Arctic into Russia's foremost base for natural resources," said Zysk. Russia's Arctic continental shelf contains more than 85 trillion cubic meters of natural gas, and 17 billion metric tons of oil, Russian state media reported in 2022. Other figures put the number at 13 billion metric tons of oil. Deck crew releasing new hydrophones Deck crew releasing new hydrophones Credits Clément Gargoullaud - Kraken Films Over the past 10 years, Russia's emphasis on the Arctic has been fed by the "belief that a lot of the economic resources that Russia is depending on are in the Arctic," from hydrocarbons to fisheries, said Gorenburg. "This is the greatest opportunity for them to develop industry," said Lage. Norway's military still has a direct line to Russia's commanders, mostly to resolve issues about fisheries and other resources, but also to avert any potential armed crises at sea between the neighbors, Lage said. Oslo shares around 120 miles of land border with Moscow, Norwegian soil stopping not far west of Russia's major military bases clustered around the Arctic cities of Murmansk and Severomorsk. The deputy commander refused to be drawn on any more specifics of how often the hotline is used, but said Oslo and Moscow spoke "when needed" and that the line of communication is always open. Russia's Build-Up in the Arctic Of course, the Arctic is crucial for Russia militarily too. At the top of its list of concerns is its huge naval and aerial presence in the Kola Peninsula, which sticks out east of Finland and Norway. These facilities are home to much of Russia's prized Northern Fleet, not least its all-important nuclear submarines and the attack submarines tasked with protecting them from any enemy strikes designed to take out Moscow's vast nuclear arsenal before they can launch. Sonar Representation of Ice Blocks Sonar Representation of Ice Blocks Credits Clément Gargoullaud - Kraken Films Russia also uses the Kola Peninsula as a jumping-off point to send submarines armed with conventional, long-range cruise missiles out toward the U.S. or the Atlantic via the waters between Greenland, Iceland and the U.K.—commonly referred to as the GIUK Gap. "The idea is that if they pass through undetected, then they could potentially put much of both Europe and the United States under threat from these cruise missile attacks," said Gorenburg. "They certainly could launch those missiles from the Arctic, but the range is such that they're better off going farther into the open ocean, rather than staying in the Arctic." Russia has, for quite a few years now, been reopening many of its Cold War-era Arctic bases while building new strongholds. The Simons Foundation Canada last year identified 69 military bases in the Arctic that are staffed all year round, belonging to the five of the states with coastlines in the Arctic and ranging from facilities also used by civilians to major nuclear weapons sites. Russia has 32 of these sites, with the U.S. figure standing at 10. Norway has 15 and Canada eight, according to the foundation's numbers. All the bases are in the Arctic region, but not necessarily above the line of latitude marking the Arctic Circle. Different judgment calls on what constitutes a military base, and whether it is a new facility, produce varying numbers. Either way, the shoring up of Russia's military presence in the Arctic is extensive. Russia watchers say Moscow channeled much of its efforts into strengthening its Northern Fleet on the Kola Peninsula, but also into early warning radars and a smattering of compact bases elsewhere in the Arctic, including the Franz Josef archipelago east of Norway's key outpost of Svalbard and Wrangel Island, roughly 300 miles from Alaska, that could host aircraft in a conflict. The Kremlin has a litany of other sites related to missile testing and launches as well as its space programs. Parts of the Arctic, like the Barents Sea, are a "testbed of Russian new systems," Lage said. This includes nuclear-powered torpedoes, long-range missiles, and other sophisticated technologies that are "still a high priority" for Russia. Drone equiped with Phase I high definition camera. Drone equiped with Phase I high definition camera. Credits Clément Gargoullaud - Kraken Films "I think we should be concerned" about Russia's expanding Arctic footprint, VanHerck said. There's no cause for "panic," the former commander added, "but we should make sure we monitor Russia's build-up and, more importantly, what is their intent with that build-up." "Russia's military posture in the Arctic is of grave concern," Iceland's Foreign Minister Þorgerður Katrín Gunnarsdóttir told Newsweek. "The Arctic remains central to Russia's strategic calculus, and its activities in the region go well beyond defensive measures." All this activity is propped up by a long history of Russian identification with the Arctic. "Geographically, it's an important part of Russia," Zysk said. "But also historically, first the Soviet Union, then Russia has taken a pride in being able to conquer this extremely difficult-to-navigate, difficult-to-live-in region." There is a self-perception of themselves as "northern people," added Gorenburg. "You see these kinds of symbolic acts in past years, even before they really started on the military build-up." Russia has repeatedly planted its tricolor flag on the North Pole, including delving down to the seabed in 2007. It has also put the work into building habitable cities with a significant civilian population—rather than just remote, military-focused outposts—above the Arctic Circle, Gorenburg said. "It's a different mentality." Has NATO Caught Up? Current and former military officials from NATO countries often concede that Russia is more comfortable operating in the Arctic. Russia's icebreaker fleet far outstrips that of any other military, an example of the country's determination to dominate the region. "Very, very few allied partners have the capability to operate over time in [the] ice-covered Arctic," said Lage. NATO nations have trouble "being able to operate not just for an exercise or two, but operate substantial forces over time," Lage said. The U.S. Navy, for example, holds its Arctic Ocean exercises, dubbed ICEX, just biennially. The ''Xue Long 2'' polar expedition icebreaker and the ''Polar'' icebreaking survey ship of the Beihai Bureau of the Ministry of Natural Resources are docking at the Qingdao Olympic Sailing Center pier in Qingdao, Shandong... The ''Xue Long 2'' polar expedition icebreaker and the ''Polar'' icebreaking survey ship of the Beihai Bureau of the Ministry of Natural Resources are docking at the Qingdao Olympic Sailing Center pier in Qingdao, Shandong province, China, on July 3, 2024. More Costfoto/NurPhoto/Getty "We need the human aspect—more research that allows humans to operate in that environment," as well as more "domain awareness," said VanHerck. This broadly refers to how a military can detect and anticipate threats in each area, and plan accordingly. It's also "very tough to communicate" in the most northern areas of the globe, the former commander said. "It's a mental shift in how we're going to operate, but I don't believe we've done enough to operate in that environment," said VanHerck. But NATO has recognized in the past few years it will need to beef up its presence in the Arctic and do more in the High North, said Dodds. In May, NATO wrapped up what it described as the alliance's "biggest and most demanding annual anti-submarine warfare (ASW) exercise," Dynamic Mongoose. The U.S. has pivoted policy to focus more northward. In 2018, it resuscitated the U.S. Navy's Second Fleet to counter Russia, including in the Arctic, closely linked with the establishment of NATO's newest command, the Virginia-headquartered Joint Force Command Norfolk. Now well into his second term, President Donald Trump hasn't changed his stance on the Arctic when placed side-by-side with his first stint in office, said Kåre Aas, who served as Norway's ambassador to the U.S. when Trump initially swept into power. The president has maintained the status quo of intelligence cooperation between the two nations as they look toward the Arctic, he said. Trump's interest is certainly clear, if not always welcome to fellow NATO members. In the early months of this year, the administration frustrated Canada with attempts to label the country the U.S.'s 51st state, and Denmark through refusing to rule out military activity to seize Greenland for "international security." These types of remarks create "anger," Aas told Newsweek, but don't diminish the need for countries like Norway to keep the U.S. firmly as a close ally. "We need to also show the Americans why Norway is important to the United States." Norway is investing in anti-submarine warfare, or ASW, an area NATO turned away from as the tensions of the Cold War washed away. Norway's military says Moscow's submarine activity was high during the Cold War but dipped in the aftermath of the disintegration of the Soviet Union. Norway detected a surge in Russian submarine operations in the early 2010s, Lage said, but no dramatic increase in the last handful of years. Royal Canadian Air Force CP-140 Aurora arrives at Joint Base Pearl Harbor-Hickam, Hawaii, for Exercise Rim of the Pacific (RIMPAC) 2024, July 3. Twenty-nine nations, 40 surface ships, three submarines, 14 national land forces, more... Royal Canadian Air Force CP-140 Aurora arrives at Joint Base Pearl Harbor-Hickam, Hawaii, for Exercise Rim of the Pacific (RIMPAC) 2024, July 3. Twenty-nine nations, 40 surface ships, three submarines, 14 national land forces, more than 150 aircraft and 25,000 personnel are participating in RIMPAC in and around the Hawaiian Islands, June 27 to Aug. 1. The world's largest international maritime exercise, RIMPAC provides a unique training opportunity while fostering and sustaining cooperative relationships among participants critical to ensuring the safety of sea lanes and security on the world's oceans. RIMPAC 2024 is the 29th exercise in the series that began in 1971. More U.S. Navy photo by Mass Communication Specialist 1st Class William Sykes Countries like Norway—plus others, including the U.K. and Germany—have beefed up anti-submarine aircraft fleets, most notably the P-8 Poseidon. Throughout July, Norway's military carried out P-8 training flights up and around Svalbard. Lage said Norway was "operating P-8s on [an] almost daily basis in the Barents Sea, in the Norwegian Sea and around Svalbard, wherever it's needed." Oslo is also investing in new frigates for anti-submarine warfare and submarines, although they won't be nuclear boats. But this branch of warfare is difficult and always has been, Lage said. "This is an ever-ongoing game between ever new, better submarines, and better ASW equipment," Lage added. "The greatest challenge today is the numbers—we have so few units, so international allied cooperation and [an] increase in numbers of capabilities, that is the most pressing [thing] today." "We are short on ASW capabilities" across NATO, he added. "We need to invest more." And, like in Europe, NATO still leans heavily on the U.S. to provide much of the alliance's most expensive capabilities in the Arctic region. This isn't just limited to the number of submarines, but also the sensor networks. But no individual NATO country can stare down Russia alone in the Arctic, current and former officials say—not even the U.S. "We need to operate as an alliance," VanHerck said. Russian President Vladimir Putin (C) poses for a group photo with naval officers of the Knyaz Pozharsky nuclear submarine's crew, while visiting the Sevmash Shipbuilding Plant, on July 24, 2025, in Severodvinsk, Arkhangelsk oblast, Russia.... Russian President Vladimir Putin (C) poses for a group photo with naval officers of the Knyaz Pozharsky nuclear submarine's crew, while visiting the Sevmash Shipbuilding Plant, on July 24, 2025, in Severodvinsk, Arkhangelsk oblast, Russia. Putin visited main Russia's military shipbuilding plant, marking the upcoming day of Russian Navy. More Contributor/Getty Back on the NRV Alliance, the context to their research hangs heavy in the air. "This is something that we are very conscious about," Real said from on board the ship, shortly after it docked in Tromsø. It would be hard not to be—especially after a Russian aircraft passed close over the vessel as it headed north near Svalbard not long after setting off. It was thought to be one of Russia's Tu-142 maritime patrol aircraft or an Il-38, but it was difficult for the crew to be sure. For the moment, officials and experts say, no one wants conflict in the Arctic. But there's no ignoring the growing competition in a region many countries are more interested in than ever. "It's very quiet—until it's not quiet anymore," said Lage.
Wall Street Journal
2 days ago
- Wall Street Journal
Very Cold War: Brutal Arctic Conditions Are Testing U.S. and Allied Forces
Elite combat troops shred their physiques to look like Hollywood hunks. In the Arctic, that can kill you. The cold eats away at soldiers, who lose on average 3,000 calories a day while on exercises in the Arctic Circle—even while eating full rations and before they have taken part in any strenuous activity.
Vox
2 days ago
- Vox
Scientists warn that climate change could wipe out more than half of these beloved animals
is an environmental correspondent at Vox, covering biodiversity loss and climate change. Before joining Vox, he was a senior energy reporter at Business Insider. Benji previously worked as a wildlife researcher. Wild reindeer search for food under the midnight sun on the Svalbard archipelago in the Arctic Circle. Ben Birchall/PA Wire It's bad enough that climate change is ruining the dream of a white Christmas for many people, as warming makes snow in some regions less likely. Now, apparently, it's coming for reindeer, too. Reindeer aren't just creatures of Christmas myth but real animals — a kind of deer that live in the Arctic, from northern Europe and Russia to North America, where they're commonly known as caribou. These animals are remarkably adapted to cold weather, sporting thick fur, a snout that warms the air they take in, and uniquely structured hooves that help them shovel snow to find food, such as lichen. But they've also survived bouts of Arctic warming that occurred thousands of years ago, thanks to their ability to travel long distances in search of colder habitats. These adaptations are, however, no match for modern climate change. The Arctic is warming quickly from a higher baseline temperature compared to natural fluctuations in the distant past. A reindeer runs in the snow in the Murmansk Region of Russia. Pavel Lvov/Sputnik via AP Over the last few decades, wild Arctic reindeer populations have declined by about two-thirds, from 5.5 million to around 1.9 million, largely due to warming, according to previous research. Rising temperatures can affect reindeer health directly — causing the animals to overheat and get sick — and indirectly by limiting their supply of food. Now, it's clear those declines will likely continue. A new study in the journal Science Advances found that if the world doesn't quickly rein in greenhouse gas emissions, the global wild reindeer population, including caribou, could plummet by nearly 60 percent by the end of the century. Those declines will be far more severe in North America, where they could exceed 80 percent, according to the study's models, which reconstructed 21,000 years of reindeer population data using fossil records, DNA, and other data sources. That's because North America is expected to lose more habitat that can support reindeer to warming than elsewhere, said Damien Fordham, a study author and researcher at the University of Adelaide. Even under a more modest emissions scenario — in which countries cut back what they spew into the atmosphere — the study projects steep population declines. You can see these results in the chart below, which shows projected declines based on a high and moderate emissions scenario, respectively. 'These results are absolutely concerning,' said Jennifer Watts, Arctic program director at the Woodwell Climate Research Center, a nonprofit research organization, who was not involved in the new study. 'Given how quickly and severely the Arctic is warming at present, the results from this study are not overly surprising, and should serve as yet another wake-up call for humans to curtail anthropogenic drivers of climate warming.' The study offers yet another example of how climate change is threatening biodiversity and how those threats in turn affect humans. Reindeer are not only a critical food source for some Arctic Indigenous communities — like Alaskan Natives and the Inuit people of North America — but also a cornerstone of their culture, similar to salmon or wolves for some tribal nations in other parts of the US. If major polluting nations, like the US, China, and India don't curtail their emissions, it could further endanger the food sovereignty of those communities. Beyond their direct impact on human well-being, reindeer also shape the tundra ecosystems — quite literally making them what they are — by limiting the growth of trees and shrubs, spreading seeds, and fertilizing the soil.
