There are more than 200 Siberian anthrax cattle burial grounds in the Russian permafrost regions. Permafrost degradation poses the risks of thawing of frozen carcasses of the infected animals and propagation of infectious diseases. Permafrost degradation leads to infiltration of toxic waste in the environment. Such waste contains mercury, which migrates into the rivers and forms methylmercury (MeHg) in fish. Other risks associated with permafrost degradation include damage to the existing social infrastructure (housing, health-care facilities, roads, etc.).
The rate of climate warming in the Arctic is greater than elsewhere in the Russian Federation. This rate is approximately twice as much as the world’s average, as was shown by the linearization of the trends in annual average temperatures of the North Polar Region over the past 40 years (1976–2018) 
Further warming will lead to even faster degradation of the permafrost layer 
. According to the IPCC, it will lead to a 90% reduction of permafrost area by 2100, and even faster degradation will happen with 20% of this area 
. The rate of permafrost degradation will depend upon local conditions and greenhouse gas emission dynamics.
An extensive network of 250 weather stations monitors ground-level air temperatures in the North Polar Region. The annual average temperatures increase, with the greatest rates along the coast of the Arctic Ocean, especially in Siberia (between +0.8 °C/10 years and +1.2 °C/10 years in the Taymyr Peninsula and the East Siberian Sea). The largest temperature anomalies have been observed in East Siberia and West Siberia. The spatially averaged values of mean annual temperature anomalies in these regions reached 5.9 and 3.7 °C, respectively 
. Since 2007, annual average ground-level temperatures have increased by 2.8 °C in East Siberia and Yakutia 
; this caused an increase in the temperatures of the upper permafrost layer by 0.4–1.3 °C 
. Annual average temperatures in West Siberia grew at the rate of 4.0–5.5 °C/100 years 
. Figure 1
presents the results of monitoring of correlations between the rates of increase in annual average air temperatures and permafrost degradation.
Air temperature anomalies and depth of seasonal permafrost thawing in 2008–2020. Seasonal thawing depths were averaged by region based on the data reported by the Circumpolar Active Layer Monitoring (CALM) program. Available online: https://www2.gwu.edu/~calm/data/north.htm
(accessed on 21 March 2022). Incomplete time series from several monitoring stations were excluded. AO—Autonomous Oblast (Region).
In Russia, the processes of permafrost degradation are most pronounced in Nenets Autonomous Oblast (AO), North Urals, West Siberia, Yamal Peninsula, and a major part of East Siberia: Krasnoyarsk region, Sakha Republic (Yakutia), Chukotka, and Kamchatka. For example, permafrost soil temperatures measured at 1.6 m depth have already increased by 0.1–1.2 °C above the norm 
. A 2 °C increase in the mean global temperature will lead to complete thawing of 15–20% of Arctic permafrost areas 
; some other researchers predicted even greater loss 
The consequences of climate change to public health in the Russian Arctic will be quite diverse, including the following: an increase in the number of heat waves will lead to excess mortality among urban populations 
; traditional lifestyles of the indigenous peoples of the North will be disrupted 
. A survey of Central Yakutia residents identified their concerns about the ongoing changes in the landscapes and weather in 2006–2016. The residents indicated that they experienced problems with accessibility of medical services and shopping; the foundations of their houses were crumbling, which was considered a direct consequence of warmer winters; and there was loss of reliable ice crossings that they used for transportation 
. There are many risks to public health caused by permafrost degradation: re-emergence of outbreaks of Siberian anthrax, and, possibly, other infections, as a result of thawing of cattle burial sites; development of infections caused by changes in vegetation (northward propagation of taiga); destruction of engineered infrastructure, including hospitals, residential houses, and roads; possible infectious contamination of foods used by the indigenous peoples of the North, as a result of thawing of glaciers; risks to deer breeding, such as injuries of the deer caused by permafrost thawing; possible destruction of shoreline constructions caused by coastal abrasion; and other types of risks.
2. Russian Arctic Permafrost Degradation Effects Public Life
2.1. Global Warming, Permafrost Degradation, and Infectious Diseases
There are indications that global warming leads to permafrost degradation, and this may facilitate the possible release of various microorganisms including pathogens. Recent research showed that prokaryote and eukaryote bacteria might remain viable in the conditions of year-round negative temperatures of permafrost soils that are from several thousand to 2–3 million years old. Viable cysts of Paleolithic bacteria have been identified that had been in a cryptobiosis state for several hundred thousand years. This finding confirmed a possibility of reactivation of vectors of infectious diseases that remained frozen in permafrost for a very long time and can be released in the environment as a result of climate changes 
The part of West Siberia beyond the Polar Circle was plagued by Siberian anthrax in the past; more than 70 large outbreaks have happened there since 1760. Such outbreaks typically occurred in the summer when the deer contracted this disease from the contaminated soils. The outbreaks became less common after a massive vaccination of domestic animals in the 1940s. There were several registered cases of Siberian anthrax among people in 1931 and 1941. After a long period of sanitary well-being without the outbreaks, the total vaccination of deer was abolished in 2007. An extremely hot summer of 2016 caused a 2 meters’ deep seasonal thawing of permafrost and, possibly, vegetation of Siberian anthrax bacteria, its migration from the active permafrost layer to the surface soil, and a consequent large-scale outbreak of Siberian anthrax among deer. Permafrost degradation may lead to migration of these bacteria to the surface with groundwater.
This entry is adapted from 10.3390/atmos13040532