© European Union 2018, Pavel Koubek. CC BY-NC-ND 2.0 via Flickr.com
In brief
News from the Arctic (2025.04)
Are heat waves the new norm in Nordic countries?
Climate change
The summer of 2025 was one of the warmest on record, with heatwaves across Europe and North America—and the usually cooler Nordic countries weren’t spared. In mid-July, a two-week-long heatwave gripped Norway, Sweden and Finland. Temperatures in parts of Norway and Sweden reached up to 35°C, while Finland had its longest heatwave on record.
According to a study by World Weather Attribution, human-caused climate change made the Nordic heatwave at least 10 times more likely and around 2°C hotter than it would have been in a world without climate change. The study warns that similar heat events will become five times more frequent by 2100 unless there is a rapid shift away from the use of fossil fuels. It also found that the probability of prolonged periods of heat has almost doubled since 2018.
The heat resulted in a surge of hospital admissions, more wildfires, and toxic algal blooms in the three countries. It also pushed some reindeer into towns in search of food, water and shade as grazing lands dried out. Some reindeer herders warned of their animals dying.
© Lisa Hupp/USFWS
Oil and gas development plans threaten Porcupine caribou and Gwich’in People
Drilling in the Arctic
The Trump administration is pressing ahead with its plans to open the entire coastal plain of Alaska’s Arctic National Wildlife Refuge to oil and gas leasing following a federal court decision earlier this year that reinstated seven previously cancelled leases. The refuge, some 78,000 square kilometres in size, is home to polar bears, migratory birds and the Porcupine caribou herd, whose calving grounds are sacred to the Gwich’in People of Alaska and northern Canada.
However, industry interest in the refuge remains weak. A congressionally mandated lease sale in January 2025 attracted no bids, echoing the poor response to an earlier auction. Even so, Alaska’s state development agency now retains leases, and the US administration has committed to expanding leasing across the refuge as part of its broader Arctic energy agenda.
Indigenous leaders warn that drilling would fragment critical caribou habitat and threaten food security.
A bleak future for Arctic caribou
New projections
Arctic caribou could decline by as much as 80 per cent by 2100 under an emission-intensive scenario at the high end of the range of future pathways, according to a new study led by the University of Adelaide and the University of Copenhagen. The study found that climate change could cause steep declines in caribou and reindeer numbers and distribution—and that North American caribou populations are most at risk.
The international team of researchers used fossils, ancient DNA and computer models to reconstruct changes in reindeer and caribou numbers over the past 21,000 years at unprecedented resolutions. They examined how reindeer responded to past climatic events and used this information to model how they might cope with future changes.
Climate change contributed to the loss of nearly two-thirds of the world’s populations of wild reindeer and caribou over just the last three decades. The researchers warn that the situation will get much worse without major cuts to greenhouse gas emissions and increased investment in wildlife management and conservation.
© Margaret Strickland, Unsplash
Bacteria linked to livestock hoof disease found in Arctic caribou
Hoof health
A team led by the Universitat Autònoma de Barcelona has detected Treponema bacteria in the hooves of migratory Arctic caribou without any signs of disease. The team took tissue samples from 48 caribou with no visible hoof lesions and identified three species of Treponema known to cause digital dermatitis—a painful hoof disease found in cattle and sheep worldwide. In recent years, scientists have discovered these bacteria in wild elk in the US Pacific Northwest, suggesting that they can be found in both domestic and wild animals. Caribou depend on healthy hooves for long migrations, and while hoof diseases are common, it is hard to investigate them due to the remote locations that caribou inhabit in the Arctic.
The bacteria were found in hoof tissue collected during the cooler months of early spring, which suggests they can persist in Arctic conditions and may be more widespread in wild herds than previously thought. The discovery underscores the possibility that pathogens normally associated with livestock diseases could also circulate in Arctic wildlife. Further study is needed to understand what role these bacteria may play in caribou health and how climate change could influence their activity.
By WWF Global Arctic Programme
