Vulnerable populations in the Arctic

E arth’s average surface temperature is rising unusually fast. This global warming process is deemed by international scientific assessment to be predominantly due to human economic activities (1). Recent research indicates that, globally, the rate of emission of greenhouse gases is increasing (2), as is the rise in sea level and the loss of summer Arctic sea ice (3). Currently, the warming trend is ‘tracking’ at the top of the range of the previously modelled forecasts (4). Meanwhile, concerns are growing that, as higher temperatures are reached, reinforcing (‘positive’) feedback systems in nature will accelerate the process. The warming is occurring more rapidly in the higher latitudes of the northern hemisphere than in the rest of the globe. Already, since mid-twentieth century, an increase of 1 28C have occurred within the Arctic region. By later this century, for ‘medium’ global emissions scenarios, the temperature increase in the Arctic is likely to be in the range of plus 4 78C, approximately double the global average warming. Such a rise, occurring so rapidly, would place extraordinary stress on ecosystems and would disrupt many geophysical processes (including precipitation patterns, ice cover, river flows and ocean currents). Indeed, various ecosystems are already being influenced by the warming. In consequence, and more generally, life in the high-latitude north for all living beings is beginning to be affected by the direct and indirect effects of climate change. However, so far, research into the impacts of climate change has paid little attention to the risks to human health. Instead, concerns have been focused on the consequences for economic conditions, the vulnerability of industries and effects on ecosystems ‘out there’ including iconic species and assets for tourism. There is urgent need to recognise that, in addition and of particular concern human health, both physical and mental, will be affected by climate change. Those human health impacts, predominantly adverse, will result both directly from altered climatic conditions (e.g. more severe heat waves and more frequent extreme weather events) and from the diverse environmental, ecological, economic and social impacts of climate change (5). Indigenous peoples live in closer contact with nature than others and have valuable knowledge of ongoing biophysical and ecological processes. They have also, as the legacy of a long-standing nomadic lifestyle, both an adaptive capacity and knowledge of adaptation strategies that can be of great value for the wider, more urbanised, population. In this special issue of Global Health Action, contributions from researchers from all over the Arctic address different aspects of these climatic and environmental changes, with a focus on how they affect human health. We can also read about insights and opportunities. Indigenous peoples have been interviewed about what they have recentlyobserved in nature, and their conclusions from these observations. They provide insights into how important their cultural identity and social context are for their continued well-being. They have also been asked how these factors influence their choices about moving or not. There is no doubt that both the everyday life and health status of many indigenous groups are already undergoing rapid change, some of them because of climate change. This includes a higher level of mental ill-health and the health consequences of a change of diet to a more western way of eating (including a much higher intake of processed foods), causing overweight, type 2 diabetes and an increase in cardiovascular diseases. Reports of research and intervention programmes among indigenous groups in Alaska describe that risks of injury, mental stress and non-communicable diseases are increasing. Mortality rates for Alaska Natives exceed that of ‘all races’ in the USA. Interviews with reindeer herders among the Swedish Sami indicate that they are approaching the limit of resilience. Thinner ice on rivers and lakes increases risks for injuries and losses of animals, as do extreme and unpredictable weather and altered seasons. ‘Everything has been regeared’ with longer, wetter and warmer autumns, warmer winters and spring coming suddenly and earlier than before changing the traditional type of herding and making it more difficult to migrate the herds. The tree line is rising and the vegetation is changing, resulting in a shrinking of grazing lands. Other businesses, including wind power, hydropower, forestry and mining, are increasingly competing for traditional indigenous pastoral space. All this threatens the sustainability of a traditional life style, including reindeer herding. The resultant sense of grief and loss of control threaten the identity of the Sami. On the other hand, the interviewed herders also speak about the longtested adaptive capacity and of opportunities. Yet, even so, the feeling of constantly being ‘left out in the cold’ by authorities persists in their answers. Other research presented here shows that various animals, including mammals, insects and parasites, are moving their habitats in response to climate change. This, in turn, makes it possible for microorganisms to expand their territories. Hunters in northern Sweden, for example, have noticed that their dogs are being infested by more ticks, year by year. Researchers from Russia describe, for example, a recent 50-fold increase in the prevalence of tickborne encephalitis (TBE) in the northwestern part of the INVITED EDITORIAL