While the impact of climate change is widely recognised, there is still much to learn about how global warming affects infectious diseases. Zoonoses – micro-organisms transmitted from animals to humans – account for at least 70% of new infections. The COVID-19 pandemic is just one example. The fact that the Arctic is warming at a rate twice the global average makes it particularly vulnerable to infectious diseases.
The Arctic also acts as a driver of infectious diseases to the rest of the planet. Higher temperatures, shorter snow seasons and thawing permafrost all have ramifications far beyond the Arctic. For example, Svalbard has banned the burying of human bodies in the ground, as those interred in permafrost do not decompose – which means there is a danger of old diseases re-emerging as the permafrost melts.
Indigenous communities lead the fight
Professor Birgitta Evengård is the principal coordinator of the research initiative Climate-Change Effects on the Epidemiology of Infectious Diseases, and the Associated Impacts on Northern Societies (CLINF) – a Nordic Centre of Excellence (i.e. a centre that conducts research in an area considered a Nordic priority) funded by NordForsk.
At CLINF, researchers from eight countries work together to predict the consequences of climate change for the spread of infectious diseases in the Arctic. In their efforts to develop models that can forecast future outbreaks, the international research team worked with local communities, whose traditional knowledge proved especially crucial:
“The Nordic countries are home to Europe’s only indigenous population, the Sámi. Indigenous people, including around 40 different groups in Russia, play a huge role in the fight against climate change. I call them the frontline troops. They have been actively seeking to mitigate the effects of climate change for many generations. Yet, somehow, their voices have been lost in the mainstream discourse, in which they are often portrayed as victims,” explains Evengård.
Predicting regional outbreaks
Tularaemia (rabbit fever) is one of the most researched diseases in the Nordic Region and has triggered major epidemics in recent years. CLINF has studied its spread by identifying regions with both high and low risks of infection and comparing them using statistical models based on ecological and meteorological data, vegetation indices and temperatures. By combining statistical models with past observations of hydro-climatic variables (including mosquito numbers, temperature, precipitation and number of cold winter days), the CLINF team were able to determine that tularaemia is highly sensitive to hydro-climatic changes. This has made it possible to predict regional outbreaks.
“It is vitally important that we work together across the Nordic countries on climate-related diseases – not to mention with Russia, which in particular provides crucial knowledge about the tundra. Three large rivers – the Ob, the Yenisei and the Lena – flow north through Russia to the Arctic Ocean, carrying all sorts of things with them, the nature and extent of which are still unclear. Thus far, one has been able to identify various materials, micro-organisms and viruses in the river water. This is why it is so important to share data and knowledge.”