Are Nature-Based Climate Solutions in the Russian Arctic Feasible? A Review

Abstract

Arctic ecosystems are highly vulnerable to ongoing and projected climate change. Rapid warming and growing anthropogenic pressure are driving a profound transformation of these regions, increasingly positioning the Arctic as a persistent, globally significant source of greenhouse gases. In the Russian Arctic—a critical zone for national economic growth and transport infrastructure—intensive development is replacing natural ecosystems with anthropogenically modified ones. In this context, Nature-based Solutions (NbS) represent a vital tool for climate change adaptation and mitigation. However, many NbS successfully applied globally have limited applicability in the Arctic due to its inaccessibility, short growing season, low temperatures, and permafrost. This review demonstrates the potential for adapting existing NbS and developing new ones tailored to the Arctic’s environmental and socioeconomic conditions. We analyze five key NbS pathways: forest management, sustainable grazing, rewilding, wetland conservation, and ecosystem restoration. Our findings indicate that protective and restorative measures are the most promising; these can deliver measurable benefits for both climate, biodiversity and traditional land-use. Combining NbS with biodiversity offset mechanisms appears optimal for preserving ecosystems while enhancing carbon sequestration in biomass and soil organic matter and reducing soil emissions. The study identifies critical knowledge gaps and proposes priority research areas to advance Arctic-specific NbS, emphasizing the need for multidisciplinary carbon cycle studies, integrated field and remote sensing data, and predictive modeling under various land-use scenarios.

1. Introduction

1.1. Rapidly Changing Arctic

Temperatures in the Arctic have been rising nearly four times faster than the average rate of global warming since 1979 [1]. This rapid rise in temperatures is primarily attributed to the reduction in sea ice cover and the effective positive albedo feedback, as well as the peculiarities of atmospheric circulation in the region [2]. According to the IPCC, temperatures in the Russian Arctic will rise by 2.9–3.1 °C by 2040 and 4.3–10.6 °C by 2100 [3]. The greatest rate of change in surface temperature is expected in the Yamalo-Nenets Autonomous Okrug (YaNAO), as well as in the coastal areas of the Asian part of the Arctic Zone of the Russian Federation (up to 1.5 °C/10 years) [4].

Arctic ecosystems are extremely sensitive to global climate change and can have a feedback effect on it. This process is largely determined by the characteristics of the biogeochemical carbon cycle. The current estimate of organic carbon in permafrost is 1400–1600 Pg C [5,6]. Of this stock, 65–70% (1035 ± 150 Pg) of carbon is found in the surface layer (depth 0–3 m). Carbon stocks in soils and frozen ground in permafrost regions are comparable to global soil carbon stocks ≈ 1700 Pg C and are at least twice the mass of carbon in the atmosphere ≈ 890 Pg C [6]. For example, so-called yedoma ice-rich deposits of Eastern Siberia and Alaska are estimated to hold as much as 327–466 Pg C [7].

However, it is the permafrost that is subject to climate-driven degradation, with its temperatures having risen during the reference decade between 2007 and 2016 by 0.39 ± 0.15 °C in the continuous zone and 0.20 ± 0.10 °C in the discontinuous zone [8]. Therefore, the problem of permafrost protection is considered a critical issue on the global climate agenda, and the Arctic is considered a key region in global climate policy [9,10,11].

Various carbon balance assessments indicate that Arctic ecosystems can act as both carbon sinks and carbon sources [12]. During 2001–2020, the Arctic and Boreal zones were a CO₂ sink of −548 ± 140 Tg C yr⁻¹ (≈−0.55 ± 0.14 Pg C yr⁻¹, ≈−2.0 ± 0.5 GtCO₂e yr⁻¹), while >30% of the area acted as sources of carbon dioxide [13]. Wildfires emitted an average of 237 Tg C yr⁻¹ (≈0.24 Pg C yr⁻¹, ≈0.88 GtCO₂e yr⁻¹) (43% of the total CO₂ sink in the Arctic and Boreal zones).

It has been shown that the annual CO₂ balance is changing due to increased emissions in winter [14], with local conditions such as nitrogen availability and water regime affecting the carbon budget. Various model estimates show that under warming conditions, the Arctic will act as a carbon emitter, and its role in the global carbon cycle will increase in the future [5]. Under different climate change scenarios, cumulative carbon dioxide emissions are projected at 55–232 Pg C (≈200–850 GtCO₂e) by 2100, depending on the warming trajectory [5].

Methane (CH₄) is the second most significant greenhouse gas, with an estimated impact on the climate that is 27–30 times stronger than that of CO₂ over a 100-year time frame [15]. Concurrently, the scientific literature continues to exhibit a degree of uncertainty with regard to the Arctic’s contribution to global CH₄ emissions. Rapid warming of the boreal zone and the Arctic, especially the melting of permafrost, creates conditions for increased CH₄ emissions from wetlands, lakes, rivers, and coastal areas [16]. A review of long-term observations reveals a statistically significant trend of an 8.9% increase in methane emissions from Boreal and Arctic wetlands between 2002 and 2021, due to rising temperatures and increased ecosystem productivity [17]. Alarmist estimates of the role of methane emissions from thawing permafrost as a powerful feedback mechanism for warming are known as the methane bomb concept [18], which, however, is not supported by subsequent studies [5]. Methane emissions from permafrost regions of Siberia are estimated at 20 Tg CH₄ yr⁻¹ (≈0.56 GtCO₂e yr⁻¹, GWP₁₀₀ = 28) by mid-21st century [19], which is the lower limit of previous model estimates. Concurrently, the Arctic soils are an underestimated methane sink, whose role may increase under climate change [20,21].

The global biodiversity crisis is evident in the loss of biodiversity at various levels of its organization, the widespread distribution of modified ecosystems, and the fragmentation and disruption of natural ecosystems [22]. It is pointed out that biodiversity loss leads to a decrease in ecosystem resilience [23,24]. The conservation of biodiversity, in particular the diversity of tree species, is important for mitigating the risks of climate change [25,26]. Rapid climate change in the Arctic is also causing the transformation of biotic complexes, manifested in changes in biogeochemical cycles [27,28], changes in the structure of plant communities, for instance, shrubification [29,30], the expansion of species and community ranges to the north [31], and the introduction of alien species [32,33]. Thus, preserving Arctic biodiversity is a relevant conservation challenge [34].

Climate change in the Arctic has socio-economic effects. It plays a significant role in transforming the structure of natural resource use by indigenous populations and in infrastructure risks [35]. It is estimated that 30–50% of critical infrastructure in all permafrost regions worldwide could be affected by 2050 at current rates of warming [36]. The effect of permafrost degradation could reach $132 billion (maximum estimate), including damage to housing stock: ≈$15 billion, and linear facilities in the range of $70–100 billion [37], while the actual damage may exceed these estimates due to unaccounted factors.

Climate change could potentially lead to an increase in the incidence of the natural focal diseases and zoonoses that threaten the local population and reindeer herds [38,39]. In 2016, an outbreak of anthrax was recorded in the YaNAO, infecting 2650 reindeer and 36 people, with one fatality. One of the reasons for the epidemic was attributed to abnormally high summer temperatures, which led to the activation of soil foci of the disease [40].

At least 10–15% of Russia’s economy is concentrated in the Arctic zone of the Russian Federation. Up to 80% of natural gas and 17% of oil are produced here [41]. Seventy percent of Russia’s infrastructure in the Arctic is located in the permafrost zone, including 90% of gas production and key ports. The value of assets on permafrost soils as of 2016 was estimated at $248.6 billion, or 7.5% of Russia’s GDP [42].

According to the Strategy for the Development of the Arctic Zone of the Russian Federation [41], there are plans to build new ports and transport infrastructure, develop deposits, and expand oil and gas chemical production. Thus, anthropogenic impact in the Russian Arctic will grow, and the search for comprehensive natural solutions is urgently needed. The key climate change risks for the Russian Arctic discussed above are summarized in Figure 1.

Thus, in the context of climate risks, it is important to seek solutions for adapting to and mitigating the effects of climate change that contribute to the sequestration or reduction of greenhouse gas emissions, as well as to the conservation of biodiversity and traditional way of life in the Russian Arctic.

1.2. Nature-Based Climate Solutions

Nature-based solutions (NbS) are the human interventions in natural processes, which leads to measurable effects in the climate change mitigation or adaptation [43,44]. They should be based on the following fundamental principles [45]: (1) NbS are nature-based, they are the result of targeted human stewardship of ecosystems and do not move ecosystems further from their natural state; (2) NbS are resilient, support biodiversity and climate adaptation, and ensure sustainable food production and forestry; (3) NbS create additional long-term climate change mitigation effects; (4) NbS are quantified in terms of cumulative effects on radiative forcing, and are accounted for using measurable conservative estimates which avoids double counting; (5) NbS respect human rights and indigenous self-determination. A number of international documents, including the Paris Agreement, the European Green Deal, and the Kunming–Montreal Global Biodiversity Framework, emphasize the role of NbS in mitigating the effects of climate change and preserving biodiversity [46].

The most important criterion for NbS is the correct determination of the baseline, as the level of net greenhouse gas emissions when implementing a scenario without additional activities. The reductions in emissions and/or increases in absorption achieved as a result of the measures taken represent the difference between the baseline and the actual level of net greenhouse gas emissions (in tons of CO₂ equivalent). Risk management must be implemented in any NbS project—the activity may not lead to the desired amount of carbon sequestration, have zero effect, or lead to an increase in emissions. The key risks of natural climate projects are considered to be carbon leakage, volatility, financial and reversal risks.

The objectives of ecosystem-based climate projects extend beyond carbon sequestration to include sustainable ecosystem management, conservation, and, where feasible, the enhancement of ecosystem services’ quality and volume. This aligns with existing NbS classifications, which are intrinsically linked to key ecosystem services [47]. Consequently, such projects must avoid adverse impacts on biodiversity and instead generate positive outcomes [48]. In addition, NbS must have a socio-economic context. While potentially feasible with existing technologies, they should not interfere with traditional land use or worsen the lives of indigenous people [45].

The implementation of natural climate solutions requires an ecosystem approach. Complex interactions between ecosystem components mean that solutions for some types of ecosystems are not applicable to others, while the functioning of many ecosystems is directly or indirectly influenced by human activity [49]. A recent review based on 257,266 publications on the topic of NbS [50] noted an imbalance in research. Thus, 87% of scientific research is devoted to ecosystem management, while 30% is devoted to protection and 29% to restoration. The authors point to the fact that existing research focuses on NbS with a high evidence base but with low potential, while there is little discussion of promising solutions.

More than 100 methodologies for various types of NbS have been developed worldwide [51], however, methodologies for solutions for the Arctic have not yet been developed. NbS reviews for Russia [51], Canada [52], and the United States [53] do not contain specific solutions for the Arctic. However, the Arctic context—permafrost, short growing season, low ecosystem productivity, and inaccessibility—dictates the need for specific natural and climatic solutions. Sixty-one promising nature-based solutions for the Arctic, including eight for terrestrial ecosystems, are proposed on the portal https://climateinterventions.org/ (accessed on 18 August 2025) [54].

The aim of the study is to assess the prospects for the application of NbS for climate change adaptation and mitigation in the Arctic zone of the Russian Federation to identify gaps in knowledge and promising areas for further research. In this review, we consider only ecosystem solutions and leave out of focus such controversial projects as geoengineering through the injection of aerosols into the stratosphere [55].

2. Materials and Methods

In the context of this study, we considered the geographical boundaries of the Arctic within the framework of the Arctic Monitoring and Assessment Programme (AMAP) [56] approach. To analyze information on the territory of Russia, we used the boundaries of the Arctic zone of the Russian Federation (AZRF)—the administrative definition of the Arctic boundaries.

We conducted a systematic literature analysis following the PRISMA 2020 framework [57] (Figure 2). A search was performed across the Web of Science, Scopus, and Google Scholar databases using the keyword combination: (“nature-based climate solution” OR “climate solutions”) AND (“arctic” OR “polar” OR “permafrost”). This search yielded 1026, 1426, and 200 records from each database, respectively, covering publications from 2000 to 2025. We then combined all the extracted data into a single document and removed duplicate articles by title. For the remaining 2249 publications, we conducted a two-step screening. At the first step, titles and abstracts were screened to identify only peer-reviewed articles mentioning terrestrial ecosystems, global cold biomes, the carbon biogeochemical cycle, or its constituent elements. Publications were categorized as “potentially relevant” or “definitely irrelevant” resulting in 529 selected publications. During the second step, the titles and abstracts of these publications were assessed for specific mentions of nature-based solutions (NbS), climate change adaptation and mitigation measures, and/or biodiversity conservation, yielding 156 publications. A full-text analysis of these was conducted. We selected 35 publications that explicitly discussed NbS in the Arctic and other permafrost regions. Studies of global scope without a specific focus on the Arctic or other cold biomes were excluded. All screening stages were performed independently by two researchers. Any discrepancies in publication selection were resolved by the first author. Finally, we employed the bibliometrix R package version 5.1.0 [58] to perform two analytical procedures: (1) generating a keywords co-occurrence network using the (biblioNetwork) function, and (2) constructing a conceptual structure map based on article abstracts using the (conceptualStructure) function.

We used the map units of the “Biomes of Russia” map as reference of regional ecosystem diversity for comparative geographical analysis [59]. To analyze the potential of NbS, we selected two key regions of the AZRF within YaNAO and in Republic of Sakha (Yakutia), since these regions were considered to be at the highest risk from climate change [4].

We analyzed open spatial products from the global forest change map (GFCM) [60], map of forest losses from fires [61], Global Land Cover and Land Use Change, 2000–2020 (GLCLU) maps [62] (spatial resolution ≈ 30 m for both products), and Northern Hemisphere permafrost map [63] (spatial resolution ≈ 1 km).

We calculated zonal statistics between these raster products and the vector layer of the map “Biomes of Russia” [59], which was intersected with data on the administrative-territorial division of the AZRF. For these operations we use the (mask) and (cellSize) functions of the terra package [64] and the (exact_extract) function of the exactextractr package [65].

To summarize the feasibility of each possible NbS pathway we used a qualitative scale: High/Medium/Low for short-term feasibility; High/Medium/Low for co-benefits. We assigned these categories based on an expert analysis of publication and spatial statistics.

3. Results and Discussion

3.1. The State of Knowledge and Research Gaps

An analysis of search queries showed that although thousands of scientific articles were devoted to the discussion of the NbS in general [50], publications focusing on the Arctic were very scarce; we found only 35 relevant peer-reviewed articles. Most of the articles were published in the period from 2020 (Figure 3).

The results of bibliometric analysis are grouped into three distinct clusters based on both keywords and abstract texts (Figure 4). The first two axes of the multiple correspondence analysis (MCA) explain 25% of the variance (Figure 4B).

The red cluster, labeled “climate change”, addresses the issue of changing natural components and processes in the Arctic, encompassing both elements of the carbon balance and biodiversity. It shows a minor overlap with the blue cluster, “climate mitigation”, which describes the opportunities and constraints of various proposed mitigation pathways under different climate change scenarios. The green cluster, “climate warnings”, does not overlap with the previous two. It encompasses assessments of risks to the entire climate system, including the radiation balance, and thermal and hydrological regimes. The identified clusters are not associated with specific NbS pathways but are instead linked to broader research directions.

A full-text analysis of publication topics revealed that 25 publications (71%) discussed only one pathway, 9 (35%) discussed two, and one publication discussed all the pathways under consideration. Of these, 13 (37%) of them discuss rewilding (Figure 5). Eleven publications each were devoted to forest and pasture management, and seven to wetland and peatland management and ecosystem restoration.

The scarcity of relevant publications, coupled with their general character, points to a limited theoretical foundation for NbS in the Arctic. The existing scientific research on NbS in the Arctic is incommensurate with the role of this macro-region in the global carbon cycle. Thus, there has been a linear increase in the number of scientific publications devoted to the carbon cycle in Arctic and permafrost zones [5].

3.2. Forest in the Arctic

Forest climate projects are the most widespread group of natural solutions; the potential of such NbS worldwide is estimated at 16.2 million tons of CO₂e yr⁻¹ or a two-thirds of all global cost-effective NbS mitigation [47]. This NbS include measures to prevent the conversion of forests to non-forest lands, forest restoration, forest management, forest plantation management, and reducing the use of wood as fuel while expanding its use for the production of building materials, furniture, and other products capable of storing the carbon accumulated in wood for a long time [51]. According to estimates for Russia, Canada, and the United States, forest management is one of the most cost-effective NbS scenarios [52,53,66].

Coniferous oligodominant forests and sparse forests in the Eurasian Arctic are represented by communities of several geographically distinct complexes of the boreal type, widespread in the Hypoarctic [67]. They form subarctic forest-tundra and northern taiga biomes [58]. These are low-productivity sparse forests formed by larch (Larix sibirica Ledeb., Larix gmelinii (Rupr.) Göpp. s.l.), spruce (Picea obovata Ledeb.), and birch (Betula pubescens Ehrh. s.l.) which form ecosystems with slow tree growth and recovery rates after disturbances. A special role in assessing the Arctic carbon budget is assigned to the most widespread communities of dominant formations, primarily larch forests [68]. At the same time, carbon stocks in these forests are significant both directly in the tree stand and in the forest litter, which is due to slow decomposition rates associated with low organic matter turnover. According to the authors’ estimates for the Arctic regions of Northeast Asia dominated by larch forests, the carbon content (taking into account trunks, roots, branches, tree needles, undergrowth, shrubs, and living ground cover) in Yakutia is 3526 million tons, in the Magadan region—156 million tons and in the Chukotka Autonomous Okrug—28.0 million tons [68]. On average, Arctic forests act as sinks of −0.2 to −0.5 t C ha⁻¹ yr⁻¹, but their carbon balance is highly variable in time and space [13]. In young larch forests (up to 50–80 years old), CO₂ emissions prevail, as soil respiration and organic matter decomposition exceed biomass growth [68]. Old-growth forests (100–200 years old) become net carbon sinks, accumulating carbon in wood and soil organic matter. Carbon stock in larch forests of NE Asia decreased by ≈1.9 Pg C between 1993–2003 due to forest loss [68]. The main risks to larch forest ecosystems in terms of maintaining the carbon balance are fires, the intensification of which is linked to climate change and the degradation of permafrost [69].

One of the key indicators of climate change in Arctic terrestrial ecosystems is “greening” and “browning”—positive or negative trends in empirical vegetation indices from remote sensing data [57], such as NDVI [70]. The high-latitude forests of Siberia show greening trends, which may indicate an increase in productivity and aboveground biomass, tree and shrub growth due to climate change [71]. Experimental data show that the vegetation shift in an Arctic subregion from less to more productive types through the replacement of tundra by shrub or forest communities can lead to a loss of soil carbon that quantitatively exceeds the carbon gain from the increase in shrub aboveground biomass [72]. Climate change contributes to shifts in forest communities with the replacement of light coniferous by dark coniferous forests [73] and an increase in canopy closure [74]. In the context of climate change, the biosphere functions of Arctic forests are of global importance.

In Russia, about two-thirds of all forests grow on permafrost, primarily in Siberia and the Far East [75]. Both the forest and the components of the forest phytocenosis play a key role in preserving permafrost [76]. Fires drastically reduce carbon stocks and can turn the ecosystem into a source of CO₂ emissions for several decades, until the vegetation cover and topsoil horizons are restored [77,78]. Fires play a decisive role in surface albedo and active layer characteristics [79]. Among the characteristics of forest fires, burning intensity is a critical property that determines permafrost stability through the combustion of insulating organic matter, vegetation, and post-fire albedo changes [80,81]. The impact of fires on permafrost is also determined by regional and landscape specifics (terrain conditions, soil type and moisture content, subsurface ice content, as well as vegetation properties) [82,83]. The recovery of active soil layer thickness after fires in the Arctic can take decades [84].

Although warming and greening may enhance the sink function, this trend is partially offset by increased respiratory losses and the risks of permafrost degradation [71]. Thus, Arctic forests cannot be classified unequivocally as either sinks or sources: their role depends on the age of the stands, climatic conditions, and the frequency of fires. On average, they remain net carbon sinks, but under climate change conditions, the likelihood of them becoming carbon sources increases.

According to the GFCM [60], forests in the Arctic zone of the Russian Federation have suffered catastrophic losses over the past decades. Deforestation is most extensive in the Northern West Siberian northern taiga biome, where between 2000 and 2023 the forest area decreased by 13,000 square kilometers, up to 10% of the biome’s forest area in 2000 (Figure 6;

Table A1. Land cover change in the biomes of the Yamalo-Nenets Autonomous Okrug.

Biomes Index	Bioms	Tree Cover 2000, sq. km	Forest Loss (2000–2023), sq. km	Forest Loss Share (2000–2023), %	Forest Loss (% of 2000 area)	Open Sand, sq. km	Open Sand Share, %	Built-Up Areas, sq.km	Built-Up Areas Share, %
2	Novozemelsko-Yamalo-Gydan Arctic tundra	0	0	0	0	725.8	2	0	0
5a	Northern hypoarctic Kola-Bolshezemelsko-Taz tundra	0	0	0	0	445.9	6	0.6	0.001
5b	Southern hypoarctic Kola-Bolshezemelsko-Taz tundra	6500.8	2672.6	1	41	1340.0	1	204	0.1
11a	Northern West Siberian forest-tundra	27,947.9	3977.9	4	14	445.1	1	346	0.3
11b	Northern West Siberian northern taiga	125,261.1	12,722.4	5	10	1193.3	0.3	584	0.2
38.1	Hypoarctic Polar Ural tundra	599.6	13.7	0.1	2	-	-	26	0.2
41.2	Hypoarctic Northern Ural tundra	1491.9	47.3	1	3	-	-	2	0.03

). A significant reduction in forest area occurred in the Northern West Siberian forest-tundra biome—4000 km² (14% of the biome’s forest area in 2000) and in the southern hypoarctic tundra biome—about 3000 km² (41% of the forest area in 2000). In mountain biomes, the reduction in forest area does not exceed 4%. The forest gain is insignificant, not exceeding 1% of the forest area in 2000 for all biomes. Fires are the cause of the destruction of 94% of forests. It has been shown that in the forest-tundra areas of the YaNAO, at least 40% of the territory burned during a 60-year period, and 10% experienced 2–3 fires in the interval of 15–60 years [85], thus disturbances are the main driver of vegetation change in northern Western Siberia. The reduction in forest area in the YaNAO occurred mainly in the island permafrost zone (more than 99% of the area).

The areas of the Republic of Sakha (Yakutia) in the AZRF are located in an area of continuous distribution of permafrost. The percentage of deforestation is drastically high in the Anabar hypoarctic taiga biome, where, according to GFCM data, more than 90% of forests have been lost. In hypoarctic taiga biomes forest loss is estimated at 30–40%, and in northern taiga, middle taiga, and forest-tundra biomes—20–30% (Figure 6;

Table A2. Land cover change in the biomes of the Yakutia.

Biomes Index	Bioms	Tree Cover 2000, sq. km	Forest Loss (2000–2023), sq. km	Forest Loss Share (2000–2023), %	Forest Loss (% of 2000 area)	Open Sand, sq. km	Open Sand Share, %	Built-Up Areas, sq.km	Built-Up Areas Share, %
3	Taimyr-East Siberian arctic tundra	0	0	0	0	283.2	0.5	0.3	<0.01
6a	Taimyr-Central Siberian northern hypoarctic tundra	0	0	0	0	348.8	1	0.8	<0.01
6b	Taimyr-Central Siberian southern hypoarctic tundra	0	0	0	0	532.6	1	0.6	<0.01
7	Lena-Kolyma hypoarctic tundra	0	0	0	0	276.6	0.2	5.2	<0.01
12a	Kotui-Lena (Olenyok) forest-tundra	1735.4	51.2	0.1	3	1171.9	2.6	2.2	<0.01
12b	Kotui-Lena (Olenyok) northern taiga	88,018.6	20,930.3	6	24	1903.8	0.5	30.9	<0.01
13a	Nizhnekolymsky forest-tundra	14,093.4	4002.0	7	28	18.3	0.03	1.1	<0.01
13b	Nizhnekolymsky northern taiga	43,637.1	13,301.5	11	30	53.4	0.04	10	<0.01
19	Middle taiga of Central Yakutia (boreal forests)	7143.6	1935.0	13	27	277.6	2	1.6	<0.01
36	High Arctic island mountain tundra	-	-	0	0	0	0	0	<0.01
38.3	Kharaulakh Range middle Siberian Hypoarctic tundra	-	-	0	0	12,807	23	1.9	<0.01
39.1	Chukchi (Beringian, Western Chukchi) hypoarctic tundra	-	-	0	0	219.2	7.5	0	<0.01
42.2	Anabar hypoarctic taiga	282	261.6	1	93	2857	12	0.3	<0.01
43.1	Verkhoyano-Kolyma (Polousny Range) hypoarctic taiga	11,419.1	3955.3	2	35	16,773.9	10	5.1	<0.01
43.2	Verkhoyano-Kolyma (Verkhoyano-Yano-Indigirka) hypoarctic taiga	79,010.2	29,480.4	8	37	59,320.3	17	34.9	<0.01
43.3	Verkhoyano-Kolyma (Oymyakon-Omolon) hypoarctic taiga	20,030.4	6974.7	13	35	439.4	0.8	0.4	<0.01

). The main cause of forest loss is fires (99%). At the same time, forest gain during the period 2000–2023 occurred in areas occupying less than 1% of the total forested area.

Difficult access, poorly developed infrastructure, and low population density complicate the implementation of forestry NbS in the AZRF. Possible NbS pathways in these conditions include the development of ecosystem management approaches, primarily fire monitoring and approaches to forest restoration. One of the key challenges for developing NbS is assessing the feedback loops in climate change when the forest cover of Arctic forests is disturbed [86]. Its complexity is primarily related to the quantitative interpretation of data due to limited information on productivity and biomass stocks, the nature of disturbances, and the restoration pathways.

3.3. Sustainable Grazing Management in the Arctic

Reindeer herding is both a traditional livelihood for Arctic Indigenous peoples, with their well-being tied to pasture health, and a key element of their cultural identity [87,88]. In various regions of the Arctic, pastures occupy the predominant land areas [89].

The reindeer is one of the key species in Arctic ecosystems [90], influencing the composition, structure, and dynamics of plant communities [91], as well as above-ground and below-ground biomass [92]. At the same time, the impact of grazing on the composition and structure of plant communities varies in different natural zones, and different functional groups of plants have varying sensitivity to grazing [91]. Reindeer grazing affects both the carbon and nitrogen cycles in Arctic ecosystems, transforming the biochemical and physicochemical conditions for the stabilization of organic matter in soils [93,94], carbon and nitrogen stocks, and greenhouse gas fluxes [95].

NbS for pasture management have been widely tested in various regions of the world. From a NbS design perspective, pasture management can lead to increased soil carbon stocks [96] and changes in the radiation balance through surface albedo [97]. Overgrazing, on the contrary, contributes to the loss of carbon from both the soil and plant biomass [98]. The impact of grazing varies significantly depending on soil conditions and intensity. For example, a recent study showed that on soils with a clay content of more than 22%, moderate grazing can lead to carbon accumulation due to compensatory growth of root biomass, while on sandy soils there is an almost linear decrease in carbon stocks with increasing grazing intensity [99]. These results confirm the optimal grazing hypothesis [100,101], according to which moderate disturbances stimulate plant productivity and increase the supply of organic carbon to the soil [102]. Albedo management is considered one of the promising approaches to mitigating permafrost thaw [36], which reduces surface heating. It has been shown that reindeer grazing can increase surface albedo in tundras by reducing shrub abundance [103]. Moderate grazing can reduce methane emissions by reducing shrubs and increasing albedo, while overgrazing leads to increased CO₂ and CH₄ fluxes [95]. These results highlight the need to develop adaptive grazing regimes that take into account both traditional farming practices and climate effects [104].

In various regions of the Arctic, ecosystems are experiencing reindeer overgrazing [91]. The increase in reindeer populations in the 20th century led to significant degradation of vegetation in the West Siberian Arctic [105,106]. At the beginning of the 21st century, the specific area of pasture per reindeer in the YaNAO was four times less than the norm, amounting to less than 26 hectares for the entire grazing period [107]. A study of the state of pastures in the Yamalo-Nenets Autonomous Okrug conducted in 2017–2018 showed that each reindeer has between 11–25 hectares [108]. The excessively high reindeer population and the tundra degradation determine the unstable state of reindeer husbandry in the West Siberian Arctic [109]. Thus, in Yamal, the existing traditional economy leads to the winter pastures of some families being located on the summer pastures of others. At the same time, the quality of winter pastures determines grazing sustainability [110]. Overgrazing and tundra degradation pose risks to both traditional land use practices and biodiversity [104]. In the West Siberian Arctic, reindeer grazing is listed as the main risk to tundra biodiversity [111,112]: high reindeer grazing pressure has a strong negative impact on nesting bird fauna.

One of the important factors affecting grazing pressure in the tundra is the attitude of its indigenous inhabitants towards reindeer which varies from place to place: in particular, for the Nenets, the reindeer is practically a sacred animal, and the well-being of a family is measured, among other things, by the number of reindeer the regulation of which by various means may be met with resistance from herders. The most significant impact of overgrazing on the Yamal Peninsula has been the widespread formation of sands blowout sites in place of tundra with the replacement of typical tundra communities with species-poor sparce psammophyte communities [113]. The restoration of tundra vegetation in sands blowout sites can take several decades [114]. It takes at least 60–80 years to restore the disturbed lichen mat [115]. The destruction of vegetation contributes to wind erosion and further degradation of habitats, which are transformed into sand drifts and dunes, devoid of vegetation cover and often occupying vast areas. The growing extent of exposed blowout sands points to the occurrence of Arctic desertification [116]. Having its roots in the traditional land use, it threatens to destroy them. It has been shown that areas of sand drifts become centers of thawing of permafrost [117]. According to GLCLU data ([62]; classes 8–20), the area of categories corresponding to wind-blown sands in the Yamalo-Nenets Autonomous Okrug within the West Siberian Plain is 4151 km² (Figure 7). At the same time, a comparison of GLCLU data for different years does not show a significant increase of the open sand area. Published sources provide various estimates, ranging from 2228 km² for the YaNAO [118] to 5830 km² on the Yamal Peninsula alone [104]. For the Eastern European and Western Siberian Arctic, the total area of sand is estimated at 16,857 km² [116].

For Central Yamal, it has been shown that increasing grazing pressure offsets the ongoing processes of scrub encroachment in conditions of air temperature growth [119]. The authors of the study conclude that sustainable grazing is one of the possible ways to preserve tundra vegetation in the context of global warming.

As the basis of the traditional economy of the indigenous peoples, reindeer herding affects the biodiversity and biogeochemical cycles of the tundra. NbS in the Arctic is only possible under conditions of sustainable grazing that does not lead to the degradation of tundra ecosystems. Industrial development, construction of communications, roads, and industrial facilities in the oil and gas sector potentially leads to the loss of some grazing areas and, potentially, to an increased load on others [120].

A potential area for NbS is the regulation of reindeer population (taking into account the above-mentioned aspects of the indigenous tundra peoples’ cultural attitude towards reindeer) and grazing regimes, for example through measures to support local communities in order to ensure conditions for the restoration of pastures. The successful implementation of NbS requires raising awareness among indigenous communities about sustainable land-use practices, coupled with external incentives for their adoption, modernization of tundra living conditions, and effective management of industrial impacts—especially from oil and gas operations. An optimal approach involves synergistic efforts between project operators and the herders.

Successful examples of integrating indigenous knowledge into broader practices include collecting data on sacred sites, analyzing local residents’ memories of hazardous places—which often correspond to areas with natural disease foci—and documenting interannual fluctuations in key ecosystem services. These services encompass the availability of wild plants and mushrooms and the population dynamics of commercially relevant fish and terrestrial species.

To use this data effectively in developing environmentally and socially sound strategies, it is advisable to create a system of metrics for biodiversity and the associated ecosystem services that are essential for sustaining traditional forms of natural resource use.

3.4. Rewilding in the Arctic

Rewilding is an ecosystem restoration strategy that involves reintroducing lost components, particularly large “ecosystem engineer” species, into their former native ranges from which they were eradicated by humans. It is regarded both as a component of ecological restoration [121], and a potential climate solution [122]. This approach can complement other NbS while enhancing biodiversity conservation [123].

A meta-analysis by Trepel et al. [124] shows that wild herbivorous megafauna influences ecosystem structure and ecological processes, significantly alters soil nutrient availability, promotes the development of open vegetation structure, and reduces the abundance of smaller animals. Megafauna significantly increases ecosystem heterogeneity by influencing the spatial heterogeneity of vegetation structure and plant diversity. It has been noted that large herbivores, acting as important regulators of community composition and structure, can play a stabilizing role in the Arctic [125].

There is a hypothesis about the possibility of managing permafrost ecosystems through the rewilding of large herbivores and, thus, restoring the ecosystem role of megafauna in the Arctic [126]. Based on the analysis of paleontological and paleogeographical data, the potential capacity of pleistocene pastures was estimated at 10.5 tons of biomass per square kilometer [127], with the high role of herbivores leading to the formation of highly productive grass communities. The decline in the role of herbivores due to hunting by ancient humans led to the formation of shrub communities. In edible conditions, the restoration of the ecosystem role of herbivores can lead to a transformation of soil moisture and temperature characteristics, a change in surface albedo, and a change in the thermophysical properties of snow cover. The results of the Pleistocene Park experiment show that grazing of large herbivores in the forest-tundra enhances the carbon cycle: both CO₂ uptake (gross primary production, GPP) and CO₂ release (ecosystem respiration, R_eco) increase, while the net ecosystem exchange (NEE, i.e., the balance between GPP and R_eco) remains similar between grazed and undisturbed areas [128]. At the same time, methane emissions decrease due to reduced soil moisture, which limits the anaerobic conditions necessary for CH₄ formation. The same experiment showed [129] that in areas of drained thermokarst basins and hills (Yedoms), the average carbon content was six times higher in the upper 38 cm (minimum depth of the active layer) compared to similar areas without grazing. Despite existing models [130], there is currently insufficient field verification experience of the capabilities of such NbS. At the same time, it is emphasized that the inclusion of large herbivores in biogeochemical models is important for carbon balance assessments [130].

In the Arctic, rewilding experiments are still rare. In the Russian Arctic, there are initiatives to rewild muskox [131], a key Arctic ecosystem “engineer” that influences the composition of plant communities, biomass, and carbon and nitrogen cycles [132,133]. It has been shown [134] that the ecological niches of reindeer and muskox overlap, and that the destruction of the muskox population is linked to human activity. Thus, initiatives to restore muskox populations may have potential as NbS, and the total potential of muskox rewilding is estimated at 0.030 ± 0.015 GtCO₂ yr⁻¹ (≈0.008 ± 0.004 Pg C yr⁻¹) [122].

When designing rewilding experiments, the key issues are the reliability and reproducibility of the relevant results. Questions remain as to whether and how animals can change the albedo, thermophysical properties of Arctic vegetation, physical and biogeochemical properties of soils in the course of their life activities. What is the carbon balance of ecosystems with the restored ecosystem role of large herbivores? How sustainable can systems with large megafauna be? What is the role of bias associated with animal care, such as feeding, in the results obtained? Accurate and precise experimental design is necessary to answer all these questions.

3.5. Restoration of Degraded Arctic Lands

Ecosystem restoration is considered one of the priority pathways of NbS [135]. It aims to activate natural ecosystem mechanisms by restoring individual components in order to restore biodiversity and ecosystem functions [136].

The Russian Arctic is a region of intensive industrial development. The construction of new industrial facilities and the expansion of both new and existing mineral deposits lead to a continuous increase in the area of degraded lands. For example, in the Nenets Autonomous Okrug, preliminary estimates suggest that disturbed areas cover no more than 1% of the territory, but they are concentrated in certain areas and can reach 8–10% [137]. In the Yamalo-Nenets Autonomous Okrug, the area of urbanized territories, according to GLCLU data [61], has almost doubled from 631 square kilometers in 2000 to 1162 square kilometers in 2020. The area of open sand dunes associated with anthropogenic impacts in this region accounts for 13% of all sandy areas [118].

The extent of anthropogenic disturbances to vegetation in the Russian Arctic has not been sufficiently studied. It has been shown that complete vegetation transformation is observed in 0.2–1.5% of gas fields on Yamal peninsula, with the area where vegetation disturbance exceeds 10% estimated at 11% and 46% of the field area, respectively [138]. The average impact area of a drilling site is estimated at 9.6 hectares, but only 0.3 hectares of vegetation is destroyed, while 6.8 hectares of vegetation is disturbed by 10%. During the construction of each kilometer of road, the area of vegetation cover disturbance is estimated at 16 hectares, of which 1 hectare is completely destroyed and 12 hectares are slightly disturbed [138]. At the same time at the Prudhoe Bay field in Alaska, approximately 34% of the territory has been disturbed since 1968 [139], and between 1990 and 2001, under warming conditions, 19% of the remaining natural landscapes (excluding water bodies and infrastructure facilities) changed their appearance as a result of the development of thermokarst phenomena, which led to the formation of a new geoecological regime. Self-restoration of main plant communities on Yamal Peninsula may take at least 30 years [138]. Meanwhile, at the Prudhoe Bay field, the effects of the disturbances of the 1940s are still being observed [140], in addition the rate of self-restoration of disturbed lands is estimated at 100 years [141].

It has been shown that disturbed areas of tundra are a source of carbon, while undisturbed areas are sinks of tens to hundreds of g C m⁻² yr⁻¹ (scaling up to Tg–Pg C at regional level) [142]. Studies in the Canadian Arctic and Alaska show that anthropogenic or climate-driven disturbance of the vegetation and soils (e.g., via thermokarst or fire) releases significant carbon stocks, turning ecosystems from carbon sinks into emission sources [10,74].

Restoring vegetation cover is a difficult task in the Arctic due to harsh climate conditions [143]. Approaches to vegetation restoration in the Arctic are still under development. They are not widely used in the Russian Arctic, despite existing theoretical developments in this area [144].

International practice has approved the use of willow cuttings [145], turf and turf fragments [146,147,148] for the Arctic ecosystems restoration. A promising approach for restoration of disturbed lands in the Arctic is the use of mosses [149] or biocrusts from cyanoprokaryotes, lichens and mosses [150,151]. Mosses, lichens and biocrusts are among the most important ecosystem “engineers” in the Arctic [152], determining patterns of soil formation [153], surface albedo [154] and patterns of carbon and nitrogen accumulation [155,156,157]. The use of biocrusts to restore disturbed lands is considered an effective approach for ecological restoration, significantly reducing wind erosion [158,159], with extensive experience in their use in arid regions. Such approaches can be combined with traditional sand stabilization methods.

Despite the potential for using local vascular plant species [160] to restore vegetation on different soils, ineffective methods of restoration using grass mixtures of “southern” grass species are used in the Russian Arctic [160]. The unsuitability of existing technologies not only reduces efficiency on the one hand, but also poses risks to biodiversity on the other. Thus, the active spread of alien plant species in the Arctic has been recorded [32], with the presence of at least 341 alien taxa documented. A total of 333 alien plant species have been recorded in the Russian Arctic [161], with 216 alien vascular plant species recorded in the West Siberian Arctic [162]. It has been shown that the introduction and spread of alien species in the Russian Arctic is currently occurring locally and is mainly associated with settlements, industrial centers, and transport routes [32].

The introduction of invasive species can result in changes in the conditions and structure of natural ecosystems, leading to a decline in their biodiversity and a reduction in the populations of native species [163]. For example, the Smooth Brome Bromus inermis Leyss., widely used for grass mixtures, is currently one of the most aggressive invasive species rapidly spreading in Alaska [164,165]. This species has been found in various areas of the West Siberian Arctic [166,167], thus demonstrating its potential for expansion in disturbed and natural grasslands.

Restoration is one of the key areas of biodiversity offsets [168,169]. Restoring ecosystems in the Arctic is a challenge, and self-restoration takes a very long time. The key focus areas of environmental restoration in the Arctic aim to establish conditions that initiate natural recovery processes across major landscape facets and to redirect and halt spontaneous degradational processes, including waterlogging, erosion, etc. [144]. In the Arctic, such solutions may have additional climate potential and be considered, reducing GHG emissions and stabilizing permafrost. However, there are many uncertainties. In particular, a scientific gap is the understanding of the thermophysical properties of vegetation cover and the potential for permafrost temperature stabilization [170]. Indigenous people can be involved in the restoration of ecosystems in the Arctic, for whom such activities can be beneficial, as well as a support measure that can potentially reduce poaching or extensive grazing. In addition, indigenous people of the tundra can be involved in harvesting restoration material—willow or moss turf— with its subsequent use in restoring modified ecosystems. It is indicated that involving indigenous people in the implementation of the NbS is one of the key areas of ensuring the sustainability of the NbS [171].

3.6. Arctic Wetlands and Peatlands

Various approaches to NbS associated with wetlands are actively developing in world practice. Among them are the exclusion of conversion of waterlogged lands, restoration of bogs, restoration of coastal and floodplain vegetation [47,52]. These solutions contribute to the long-term potential for mitigating climate change [172]. The global potential of wetland-related NbS is estimated at 1.1–2.6 GtCO₂e yr⁻¹ (≈0.30–0.71 Pg C yr⁻¹) in 2030 [173].

Wetlands in the boreal and arctic zones have an important climate-regulating function [174] and cover extensive areas, over 25% of the land area within the AMAP boundary [175] and 16.5% within the boundary of the Circumpolar Arctic Vegetation Map [176,177]. They are natural accumulators of large volumes of organic matter [178] and play key roles in regulating water balance, maintaining permafrost [179] and preserving biodiversity [180]. Arctic wetlands and peatlands are potentially vulnerable to climate change [175], and the 0.8–1.9 million km² of peatlands in permafrost areas may be potential emitters of CO₂ and CH₄ [178]. The most vulnerable to climate change are peatlands in areas of discontinuous permafrost [181]. Permafrost degradation in wetland complexes can be accompanied by the development of thermokarst [182], a relatively poorly studied process in the Arctic carbon cycle [183,184], which releases carbon accumulated in permafrost. High densities of reindeer can also lead to permafrost degradation in wetlands [185].

Arctic peatlands remain largely unexploited for peat extraction, despite the existence of applicable extraction methods [186]. Meanwhile, oil and gas development, a dominant economic activity in the region, creates numerous quarries for construction materials. After operations cease, these quarries—either hydraulically excavated or dry—often fill with water, forming deep lakes that pose significant challenges for ecological rehabilitation [187], a process that can take decades. Nevertheless, comprehensive rehabilitation measures exist, aiming to restore hydrology and initiate natural recovery [144,188].

Such ecological rehabilitation, coupled with the restoration of shoreline vegetation, will promote the accumulation of bottom sediments and, in tundra conditions, lead to waterlogging along with peat development. This process facilitates carbon sequestration through the accumulating biomass and peat of the newly formed wetland. These restoration measures can be considered NbS; however, assessments of their carbon sequestration potential in the Arctic are currently lacking.

4. Conclusions

Nature-based Solutions (NbS) are knowledge-intensive and require rigorous scientific development to verify their effectiveness and assess potential impacts [189,190]. However, a significant knowledge gap of NbS feasibility persists both in the Arctic as a whole and in its Russian part. Despite a long history of research in the Russian Arctic, natural factors and processes governing the regional carbon balance remain poorly understood due to the territory’s remoteness and fragmented (“island”) pattern of development. Most carbon cycle studies are concentrated in Alaska and northeastern Canada, leaving vast and climatically sensitive areas of the Russian Arctic critically understudied [191,192,193]. This data deficit is exacerbated by the lack of a comprehensive greenhouse gas monitoring network. The Russia’s Unified National Monitoring System of Climate-Active Substances (“VIP GZ”) provides virtually no coverage of the Arctic. Currently, only a few pilot sites (e.g., “Seven Larches” in the forest-tundra) are operational, while immense tundra regions lack any representation [47]. Developing effective Arctic NbS thus requires robust data on carbon balance patterns across diverse ecosystems and anthropogenic impacts, necessitating an integrated research approach. The need to consolidate scientific efforts to build a foundation for climate adaptation and mitigation policies is widely emphasized [11].

Given its vast area and significance for the global carbon cycle, the Arctic remains a critical gap in the science underpinning NbS. Existing proposals are fragmented and fail to constitute a unified program. Moreover, evidence indicates that ecosystem interventions can lead to carbon losses and permafrost degradation [46]. Therefore, priority should be given to protective and restorative measures, such as ecosystem conservation, rehabilitation of degraded lands, and sustainable ecosystem management (Figure 8).

All proposed approaches currently involve significant uncertainties. Advancing Arctic NbS requires the consolidation of interdisciplinary research spanning geocryology, soil science, ecology, botany, zoology, and social sciences. The scope of research at carbon research and monitoring sites should extend beyond natural ecosystems to include modified ones. Furthermore, a comprehensive assessment of the carbon balance across different land use practices is essential.

As initial practical steps towards implementing such integrated solutions, we propose the following: (1) integrating carbon balance accounting into the practice of forest offsets, which is legally established in the Russian Federation and is generally being successfully implemented. This would make it possible to assess the climate contribution of forest restoration and forest management projects, and could also provide a potential impetus for the development of forest-climate projects in the Arctic; (2) extending mandatory offset requirements to the tundra biome, analogous to the provisions currently in place for forest lands in the Russian Federation; (3) enhancing the management of protected areas; (4) synergizing traditional forms of nature use (with the modernization necessary for their preservation and the safety of society as a whole) and preserving ecosystems that provide relevant services taking into account the entire geography of the relevant forms.

This should be achieved through functional zoning and the effective regulation of land and resource use. Furthermore, the practice of excluding licensed exploration areas and technical corridors from pre-established protected boundaries must be prohibited. Promising solutions with carbon sequestration potential can also deliver co-benefits for biodiversity, positioning them as potential offset mechanisms. Thus, well-designed NbS projects in the Arctic could contribute not only to climate mitigation but also to biodiversity and traditional land-use conservation goals.

In conclusion, while the implementation of NbS in the Arctic is feasible, a precautionary principle dictates a focus on protection and restoration. A synergistic approach, combining conservation, restoration, and management strategies through collaboration between the state, industry, and science, appears most promising.