Tundra

Last updated

Tundra
Greenland scoresby-sydkapp2 hg.jpg
Tundra in Greenland
800px-Map-Tundra.png
Map showing Arctic tundra
Geography
Area11,563,300 [1]  km2 (4,464,600 sq mi)
Climate type ET

In physical geography, tundra ( /ˈtʌndrə,ˈtʊn-/ ) is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term is a Russian word adapted from Sámi languages. [2] There are three regions and associated types of tundra: Arctic tundra, [3] alpine tundra, [3] and Antarctic tundra. [4]

Contents

Tundra vegetation is composed of dwarf shrubs, sedges, grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. [3] The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the permafrost, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained greenhouse gases into the atmosphere, creating a feedback cycle that increases climate change.

Arctic

Arctic tundra occurs in the far Northern Hemisphere, north of the taiga belt. The word "tundra" usually refers only to the areas where the subsoil is permafrost, or permanently frozen soil. (It may also refer to the treeless plain in general so that northern Sápmi would be included.) Permafrost tundra includes vast areas of northern Russia and Canada. [3] The polar tundra is home to several peoples who are mostly nomadic reindeer herders, such as the Nganasan and Nenets in the permafrost area (and the Sami in Sápmi).

Tundra in Siberia Tundra in Siberia.jpg
Tundra in Siberia

Arctic tundra contains areas of stark landscape and is frozen for much of the year. [5] The soil there is frozen from 25 to 90 cm (10 to 35 in) down, making it impossible for trees to grow. Instead, bare and sometimes rocky land can only support certain kinds of Arctic vegetation, low-growing plants such as moss, heath (Ericaceae varieties such as crowberry and black bearberry), and lichen. [6] [7]

There are two main seasons, winter and summer, in the polar tundra areas. During the winter it is very cold, dark, and windy with the average temperature around −28 °C (−18 °F), sometimes dipping as low as −50 °C (−58 °F). However, extreme cold temperatures on the tundra do not drop as low as those experienced in taiga areas further south (for example, Russia's, Canada's, and Alaska's lowest temperatures were recorded in locations south of the tree line). During the summer, temperatures rise somewhat, and the top layer of seasonally-frozen soil melts, leaving the ground very soggy. The tundra is covered in marshes, lakes, bogs, and streams during the warm months. Generally daytime temperatures during the summer rise to about 12 °C (54 °F) but can often drop to 3 °C (37 °F) or even below freezing. Arctic tundras are sometimes the subject of habitat conservation programs. In Canada and Russia, many of these areas are protected through a national Biodiversity Action Plan.

Vuntut National Park in Canada Vontut National Park.jpg
Vuntut National Park in Canada

Tundra tends to be windy, with winds often blowing upwards of 50–100 km/h (30–60 mph). However, it is desert-like, with only about 150–250 mm (6–10 in) of precipitation falling per year (the summer is typically the season of maximum precipitation). Although precipitation is light, evaporation is also relatively minimal. During the summer, the permafrost thaws just enough to let plants grow and reproduce, but because the ground below this is frozen, the water cannot sink any lower, so the water forms the lakes and marshes found during the summer months. There is a natural pattern of accumulation of fuel and wildfire which varies depending on the nature of vegetation and terrain. Research in Alaska has shown fire-event return intervals (FRIs) that typically vary from 150 to 200 years, with dryer lowland areas burning more frequently than wetter highland areas. [8]

A group of muskoxen in Alaska Muskox and Geese.jpg
A group of muskoxen in Alaska

The biodiversity of tundra is low: 1,700 species of vascular plants and only 48 species of land mammals can be found, although millions of birds migrate there each year for the marshes. [9] There are also a few fish species. There are few species with large populations. Notable plants in the Arctic tundra include blueberry ( Vaccinium uliginosum ), crowberry ( Empetrum nigrum ), reindeer lichen ( Cladonia rangiferina ), lingonberry ( Vaccinium vitis-idaea ), and Labrador tea ( Rhododendron groenlandicum ). [10] Notable animals include reindeer (caribou), musk ox, Arctic hare, Arctic fox, snowy owl, ptarmigan, northern red-backed voles, lemmings, the mosquito, [11] and even polar bears near the ocean. [10] [12] Tundra is largely devoid of poikilotherms such as frogs or lizards.

Due to the harsh climate of Arctic tundra, regions of this kind have seen little human activity, even though they are sometimes rich in natural resources such as petroleum, natural gas, and uranium. In recent times this has begun to change in Alaska, Russia, and some other parts of the world: for example, the Yamalo-Nenets Autonomous Okrug produces 90% of Russia's natural gas.

Relationship to climate change

A severe threat to tundra is global warming, which causes permafrost to thaw. The thawing of the permafrost in a given area on human time scales (decades or centuries) could radically change which species can survive there. [13] It also represents a significant risk to infrastructure built on top of permafrost, such as roads and pipelines.

In locations where dead vegetation and peat have accumulated, there is a risk of wildfire, such as the 1,039 km2 (401 sq mi) of tundra which burned in 2007 on the north slope of the Brooks Range in Alaska. [14] Such events may both result from and contribute to global warming. [15]

Greenhouse gas emissions

Greater summer precipitation increases the depth of permafrost layer subject to thaw, in different Arctic permafrost environments. Douglas 2020 precipitation layers.png
Greater summer precipitation increases the depth of permafrost layer subject to thaw, in different Arctic permafrost environments.

Carbon emissions from permafrost thaw contribute to the same warming which facilitates the thaw, making it a positive climate change feedback. The warming also intensifies Arctic water cycle, and the increased amounts of warmer rain are another factor which increases permafrost thaw depths. [16] The amount of carbon that will be released from warming conditions depends on depth of thaw, carbon content within the thawed soil, physical changes to the environment [17] and microbial and vegetation activity in the soil. Microbial respiration is the primary process through which old permafrost carbon is re-activated and enters the atmosphere. The rate of microbial decomposition within organic soils, including thawed permafrost, depends on environmental controls, such as soil temperature, moisture availability, nutrient availability, and oxygen availability. [18] In particular, sufficient concentrations of iron oxides in some permafrost soils can inhibit microbial respiration and prevent carbon mobilization: however, this protection only lasts until carbon is separated from the iron oxides by Fe-reducing bacteria, which is only a matter of time under the typical conditions. [19] Depending on the soil type, Iron(III) oxide can boost oxidation of methane to carbon dioxide in the soil, but it can also amplify methane production by acetotrophs: these soil processes are not yet fully understood. [20]

Altogether, the likelihood of the entire carbon pool mobilizing and entering the atmosphere is low despite the large volumes stored in the soil. Although temperatures will increase, this does not imply complete loss of permafrost and mobilization of the entire carbon pool. Much of the ground underlain by permafrost will remain frozen even if warming temperatures increase the thaw depth or increase thermokarsting and permafrost degradation. [21] Moreover, other elements such as iron and aluminum can adsorb some of the mobilized soil carbon before it reaches the atmosphere, and they are particularly prominent in the mineral sand layers which often overlay permafrost. [22] On the other hand, once the permafrost area thaws, it will not go back to being permafrost for centuries even if the temperature increase reversed, making it one of the best-known examples of tipping points in the climate system.

In 2011, preliminary computer analyses suggested that permafrost emissions could be equivalent to around 15% of anthropogenic emissions. [23]

A 2018 perspectives article discussing tipping points in the climate system activated around 2 °C (3.6 °F) of global warming suggested that at this threshold, permafrost thaw would add a further 0.09 °C (0.16 °F) to global temperatures by 2100, with a range of 0.04–0.16 °C (0.072–0.288 °F) [24] In 2021, another study estimated that in a future where zero emissions were reached following an emission of a further 1000 Pg C into the atmosphere (a scenario where temperatures ordinarily stay stable after the last emission, or start to decline slowly) permafrost carbon would add 0.06 °C (0.11 °F) (with a range of 0.02–0.14 °C (0.036–0.252 °F)) 50 years after the last anthropogenic emission, 0.09 °C (0.16 °F) (0.04–0.21 °C (0.072–0.378 °F)) 100 years later and 0.27 °C (0.49 °F) (0.12–0.49 °C (0.22–0.88 °F)) 500 years later. [25] However, neither study was able to take abrupt thaw into account.

In 2020, a study of the northern permafrost peatlands (a smaller subset of the entire permafrost area, covering 3.7 million km2 out of the estimated 18 million km2 [26] ) would amount to ~1% of anthropogenic radiative forcing by 2100, and that this proportion remains the same in all warming scenarios considered, from 1.5 °C (2.7 °F) to 6 °C (11 °F). It had further suggested that after 200 more years, those peatlands would have absorbed more carbon than what they had emitted into the atmosphere. [27]

The IPCC Sixth Assessment Report estimates that carbon dioxide and methane released from permafrost could amount to the equivalent of 14–175 billion tonnes of carbon dioxide per 1 °C (1.8 °F) of warming. [28] :1237 For comparison, by 2019, annual anthropogenic emission of carbon dioxide alone stood around 40 billion tonnes. [28] :1237

Nine probable scenarios of greenhouse gas emissions from permafrost thaw during the 21st century, which show a limited, moderate and intense CO2 and
.mw-parser-output .template-chem2-su{display:inline-block;font-size:80%;line-height:1;vertical-align:-0.35em}.mw-parser-output .template-chem2-su>span{display:block;text-align:left}.mw-parser-output sub.template-chem2-sub{font-size:80%;vertical-align:-0.35em}.mw-parser-output sup.template-chem2-sup{font-size:80%;vertical-align:0.65em}
CH4 emission response to low, medium and high-emission Representative Concentration Pathways. The vertical bar uses emissions of selected large countries as a comparison: the right-hand side of the scale shows their cumulative emissions since the start of the Industrial Revolution, while the left-hand side shows each country's cumulative emissions for the rest of the 21st century if they remained unchanged from their 2019 levels. Schuur 2022 century-scale permafrost projections.jpeg
Nine probable scenarios of greenhouse gas emissions from permafrost thaw during the 21st century, which show a limited, moderate and intense CO2 and CH4 emission response to low, medium and high-emission Representative Concentration Pathways. The vertical bar uses emissions of selected large countries as a comparison: the right-hand side of the scale shows their cumulative emissions since the start of the Industrial Revolution, while the left-hand side shows each country's cumulative emissions for the rest of the 21st century if they remained unchanged from their 2019 levels.

A 2021 assessment of the economic impact of climate tipping points estimated that permafrost carbon emissions would increase the social cost of carbon by about 8.4% [30] However, the methods of that assessment have attracted controversy: when researchers like Steve Keen and Timothy Lenton had accused it of underestimating the overall impact of tipping points and of higher levels of warming in general, [31] the authors have conceded some of their points. [32]

In 2021, a group of prominent permafrost researchers like Merritt Turetsky had presented their collective estimate of permafrost emissions, including the abrupt thaw processes, as part of an effort to advocate for a 50% reduction in anthropogenic emissions by 2030 as a necessary milestone to help reach net zero by 2050. Their figures for combined permafrost emissions by 2100 amounted to 150–200 billion tonnes of carbon dioxide equivalent under 1.5 °C (2.7 °F) of warming, 220–300 billion tonnes under 2 °C (3.6 °F) and 400–500 billion tonnes if the warming was allowed to exceed 4 °C (7.2 °F). They compared those figures to the extrapolated present-day emissions of Canada, the European Union and the United States or China, respectively. The 400–500 billion tonnes figure would also be equivalent to the today's remaining budget for staying within a 1.5 °C (2.7 °F) target. [33] One of the scientists involved in that effort, Susan M. Natali of Woods Hole Research Centre, had also led the publication of a complementary estimate in a PNAS paper that year, which suggested that when the amplification of permafrost emissions by abrupt thaw and wildfires is combined with the foreseeable range of near-future anthropogenic emissions, avoiding the exceedance (or "overshoot") of 1.5 °C (2.7 °F) warming is already implausible, and the efforts to attain it may have to rely on negative emissions to force the temperature back down. [34]

An updated 2022 assessment of climate tipping points concluded that abrupt permafrost thaw would add 50% to gradual thaw rates, and would add 14 billion tons of carbon dioxide equivalent emissions by 2100 and 35 billion tons by 2300 per every degree of warming. This would have a warming impact of 0.04 °C (0.072 °F) per every full degree of warming by 2100, and 0.11 °C (0.20 °F) per every full degree of warming by 2300. It also suggested that at between 3 °C (5.4 °F) and 6 °C (11 °F) degrees of warming (with the most likely figure around 4 °C (7.2 °F) degrees) a large-scale collapse of permafrost areas could become irreversible, adding between 175 and 350 billion tons of CO2 equivalent emissions, or 0.2–0.4 °C (0.36–0.72 °F) degrees, over about 50 years (with a range between 10 and 300 years). [35] [36]

A major review published in the year 2022 concluded that if the goal of preventing 2 °C (3.6 °F) of warming was realized, then the average annual permafrost emissions throughout the 21st century would be equivalent to the year 2019 annual emissions of Russia. Under RCP4.5, a scenario considered close to the current trajectory and where the warming stays slightly below 3 °C (5.4 °F), annual permafrost emissions would be comparable to year 2019 emissions of Western Europe or the United States, while under the scenario of high global warming and worst-case permafrost feedback response, they would nearly match year 2019 emissions of China. [29]

Antarctic

Tundra on the Kerguelen Islands. 11 Le Mont Werth (908m) devant le Ross.jpg
Tundra on the Kerguelen Islands.

Antarctic tundra occurs on Antarctica and on several Antarctic and subantarctic islands, including South Georgia and the South Sandwich Islands and the Kerguelen Islands. Most of Antarctica is too cold and dry to support vegetation, and most of the continent is covered by ice fields or cold deserts. However, some portions of the continent, particularly the Antarctic Peninsula, have areas of rocky soil that support plant life. The flora presently consists of around 300–400 species of lichens, 100 mosses, 25 liverworts, and around 700 terrestrial and aquatic algae species, which live on the areas of exposed rock and soil around the shore of the continent. Antarctica's two flowering plant species, the Antarctic hair grass (Deschampsia antarctica) and Antarctic pearlwort (Colobanthus quitensis), are found on the northern and western parts of the Antarctic Peninsula. [37] In contrast with the Arctic tundra, the Antarctic tundra lacks a large mammal fauna, mostly due to its physical isolation from the other continents. Sea mammals and sea birds, including seals and penguins, inhabit areas near the shore, and some small mammals, like rabbits and cats, have been introduced by humans to some of the subantarctic islands. The Antipodes Subantarctic Islands tundra ecoregion includes the Bounty Islands, Auckland Islands, Antipodes Islands, the Campbell Island group, and Macquarie Island. [38] Species endemic to this ecoregion include Corybas dienemus and Corybas sulcatus , the only subantarctic orchids; the royal penguin; and the Antipodean albatross. [38]

There is some ambiguity on whether Magellanic moorland, on the west coast of Patagonia, should be considered tundra or not. [39] Phytogeographer Edmundo Pisano called it tundra (Spanish : tundra Magallánica) since he considered the low temperatures key to restrict plant growth. [39]

The flora and fauna of Antarctica and the Antarctic Islands (south of 60° south latitude) are protected by the Antarctic Treaty. [40]

Alpine

Alpine tundra in the North Cascades of Washington, United States Sahale Peak.jpg
Alpine tundra in the North Cascades of Washington, United States

Alpine tundra does not contain trees because the climate and soils at high altitude block tree growth. [41] :51 The cold climate of the alpine tundra is caused by the low air temperatures, and is similar to polar climate. Alpine tundra is generally better drained than arctic soils. [7] Alpine tundra transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone (the treeline) are known as Krummholz . Alpine tundra can be affected by woody plant encroachment. [42]

Alpine tundra occurs in mountains worldwide. The flora of the alpine tundra is characterized by plants that grow close to the ground, including perennial grasses, sedges, forbs, cushion plants, mosses, and lichens. [43] The flora is adapted to the harsh conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation, and a short growing season.

Climatic classification

Tundra region with fjords, glaciers and mountains. Kongsfjorden, Spitsbergen. Kongsfjorden from Blomstrandhalvoja.jpg
Tundra region with fjords, glaciers and mountains. Kongsfjorden, Spitsbergen.

Tundra climates ordinarily fit the Köppen climate classification ET, signifying a local climate in which at least one month has an average temperature high enough to melt snow (0 °C (32 °F)), but no month with an average temperature in excess of 10 °C (50 °F). [44] The cold limit generally meets the EF climates of permanent ice and snows; the warm-summer limit generally corresponds with the poleward or altitudinal limit of trees, [45] where they grade into the subarctic climates designated Dfd, Dwd and Dsd (extreme winters as in parts of Siberia), Dfc typical in Alaska, Canada, mountain areas of Scandinavia, European Russia, and Western Siberia (cold winters with months of freezing). [46]

Despite the potential diversity of climates in the ET category involving precipitation, extreme temperatures, and relative wet and dry seasons, this category is rarely subdivided. Rainfall and snowfall are generally slight due to the low vapor pressure of water in the chilly atmosphere, but as a rule potential evapotranspiration is extremely low, allowing soggy terrain of swamps and bogs even in places that get precipitation typical of deserts of lower and middle latitudes. [47] The amount of native tundra biomass depends more on the local temperature than the amount of precipitation. [48]

Places featuring a tundra climate

Alpine tundra
Polar tundra

See also

Related Research Articles

<span class="mw-page-title-main">Taiga</span> Biome characterized by coniferous forests

Taiga, also known as boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches. The taiga or boreal forest is the world's largest land biome. In North America, it covers most of inland Canada, Alaska, and parts of the northern contiguous United States. In Eurasia, it covers most of Sweden, Finland, much of Russia from Karelia in the west to the Pacific Ocean, much of Norway and Estonia, some of the Scottish Highlands, some lowland/coastal areas of Iceland, and areas of northern Kazakhstan, northern Mongolia, and northern Japan.

<span class="mw-page-title-main">Cryosphere</span> Those portions of Earths surface where water is in solid form

The cryosphere is an all-encompassing term for the portions of Earth's surface where water is in solid form, including sea ice, lake ice, river ice, snow cover, glaciers, ice caps, ice sheets, and frozen ground. Thus, there is a wide overlap with the hydrosphere. The cryosphere is an integral part of the global climate system. It also has important feedbacks on the climate system. These feedbacks come from the cryosphere's influence on surface energy and moisture fluxes, clouds, the water cycle, atmospheric and oceanic circulation.

<span class="mw-page-title-main">Polar climate</span> Climate classification

The polar climate regions are characterized by a lack of warm summers but with varying winters. Every month a polar climate has an average temperature of less than 10 °C (50 °F). Regions with a polar climate cover more than 20% of the Earth's area. Most of these regions are far from the equator and near the poles, and in this case, winter days are extremely short and summer days are extremely long. A polar climate consists of cool summers and very cold winters, which results in treeless tundra, glaciers, or a permanent or semi-permanent layer of ice. It is identified with the letter E in the Köppen climate classification.

<span class="mw-page-title-main">Permafrost</span> Soil frozen for a duration of at least two years

Permafrost is soil or underwater sediment which continuously remains below 0 °C (32 °F) for two years or more: the oldest permafrost had been continuously frozen for around 700,000 years. While the shallowest permafrost has a vertical extent of below a meter (3 ft), the deepest is greater than 1,500 m (4,900 ft). Similarly, the area of individual permafrost zones may be limited to narrow mountain summits or extend across vast Arctic regions. The ground beneath glaciers and ice sheets is not usually defined as permafrost, so on land, permafrost is generally located beneath a so-called active layer of soil which freezes and thaws depending on the season.

<span class="mw-page-title-main">Alpine tundra</span> Biome found at high altitudes

Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets lower until it reaches sea level, and alpine tundra merges with polar tundra.

<span class="mw-page-title-main">Tree line</span> Edge of the habitat at which trees are capable of growing

The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions. The tree line is sometimes distinguished from a lower timberline, which is the line below which trees form a forest with a closed canopy.

<span class="mw-page-title-main">Polar desert</span> Region of the Earth

Polar deserts are the regions of Earth that fall under an ice cap climate. Despite rainfall totals low enough to normally classify as a desert, polar deserts are distinguished from true deserts by low annual temperatures and evapotranspiration. Most polar deserts are covered in ice sheets, ice fields, or ice caps, and they are also called white deserts.

Polar ecology is the relationship between plants and animals in a polar environment. Polar environments are in the Arctic and Antarctic regions. Arctic regions are in the Northern Hemisphere, and it contains land and the islands that surrounds it. Antarctica is in the Southern Hemisphere and it also contains the land mass, surrounding islands and the ocean. Polar regions also contain the subantarctic and subarctic zone which separate the polar regions from the temperate regions. Antarctica and the Arctic lie in the polar circles. The polar circles are imaginary lines shown on maps to be the areas that receives less sunlight due to less radiation. These areas either receive sunlight or shade 24 hours a day because of the earth's tilt. Plants and animals in the polar regions are able to withstand living in harsh weather conditions but are facing environmental threats that limit their survival.

<span class="mw-page-title-main">Drunken trees</span> Stand of trees displaced from their normal vertical alignment

Drunken trees, tilted trees, or a drunken forest, is a stand of trees rotated from their normal vertical alignment.

<span class="mw-page-title-main">Arctic ecology</span> Study of the relationships between biotic and abiotic factors in the arctic

Arctic ecology is the scientific study of the relationships between biotic and abiotic factors in the arctic, the region north of the Arctic Circle. This region is characterized by two biomes: taiga and tundra. While the taiga has a more moderate climate and permits a diversity of both non-vascular and vascular plants, the tundra has a limited growing season and stressful growing conditions due to intense cold, low precipitation, and a lack of sunlight throughout the winter. Sensitive ecosystems exist throughout the Arctic region, which are being impacted dramatically by global warming.

<span class="mw-page-title-main">Climate change in the Arctic</span> Impacts of climate change on the Arctic

Major environmental issues caused by contemporary climate change in the Arctic region range from the well-known, such as the loss of sea ice or melting of the Greenland ice sheet, to more obscure, but deeply significant issues, such as permafrost thaw, as well as related social consequences for locals and the geopolitical ramifications of these changes. The Arctic is likely to be especially affected by climate change because of the high projected rate of regional warming and associated impacts. Temperature projections for the Arctic region were assessed in 2007: These suggested already averaged warming of about 2 °C to 9 °C by the year 2100. The range reflects different projections made by different climate models, run with different forcing scenarios. Radiative forcing is a measure of the effect of natural and human activities on the climate. Different forcing scenarios reflect things such as different projections of future human greenhouse gas emissions.

<span class="mw-page-title-main">Tipping points in the climate system</span> Large and possibly irreversible changes in the climate system

In climate science, a tipping point is a critical threshold that, when crossed, leads to large, accelerating and often irreversible changes in the climate system. If tipping points are crossed, they are likely to have severe impacts on human society and may accelerate global warming. Tipping behavior is found across the climate system, for example in ice sheets, mountain glaciers, circulation patterns in the ocean, in ecosystems, and the atmosphere. Examples of tipping points include thawing permafrost, which will release methane, a powerful greenhouse gas, or melting ice sheets and glaciers reducing Earth's albedo, which would warm the planet faster.

<span class="mw-page-title-main">Arctic methane emissions</span> Release of methane from seas and soils in permafrost regions of the Arctic

Arctic methane release is the release of methane from Arctic ocean waters as well as from soils in permafrost regions of the Arctic. While it is a long-term natural process, methane release is exacerbated by global warming. This results in a positive climate change feedback, as methane is a powerful greenhouse gas. The Arctic region is one of many natural sources of methane. Climate change could accelerate methane release in the Arctic, due to the release of methane from existing stores, and from methanogenesis in rotting biomass. When permafrost thaws as a consequence of warming, large amounts of organic material can become available for methanogenesis and may ultimately be released as methane.

<span class="mw-page-title-main">North American Arctic</span>

The North American Arctic is composed of the northern polar regions of Alaska (USA), Northern Canada and Greenland. Major bodies of water include the Arctic Ocean, Hudson Bay, the Gulf of Alaska and North Atlantic Ocean. The North American Arctic lies above the Arctic Circle. It is part of the Arctic, which is the northernmost region on Earth. The western limit is the Seward Peninsula and the Bering Strait. The southern limit is the Arctic Circle latitude of 66° 33’N, which is the approximate limit of the midnight sun and the polar night.

<span class="mw-page-title-main">Climate change feedbacks</span> Feedback related to climate change

Climate change feedbacks are effects of global warming that amplify or diminish the effect of forces that initially cause the warming. Positive feedbacks enhance global warming while negative feedbacks weaken it. Feedbacks are important in the understanding of climate change because they play an important part in determining the sensitivity of the climate to warming forces. Climate forcings and feedbacks together determine how much and how fast the climate changes. Large positive feedbacks can lead to tipping points—abrupt or irreversible changes in the climate system—depending upon the rate and magnitude of the climate change.

<span class="mw-page-title-main">Permafrost carbon cycle</span> Sub-cycle of the larger global carbon cycle

The permafrost carbon cycle or Arctic carbon cycle is a sub-cycle of the larger global carbon cycle. Permafrost is defined as subsurface material that remains below 0o C for at least two consecutive years. Because permafrost soils remain frozen for long periods of time, they store large amounts of carbon and other nutrients within their frozen framework during that time. Permafrost represents a large carbon reservoir, one which was often neglected in the initial research determining global terrestrial carbon reservoirs. Since the start of the 2000s, however, far more attention has been paid to the subject, with an enormous growth both in general attention and in the scientific research output.

<span class="mw-page-title-main">Canadian Arctic tundra</span>

The Canadian Arctic tundra is a biogeographic designation for Northern Canada's terrain generally lying north of the tree line or boreal forest, that corresponds with the Scandinavian Alpine tundra to the east and the Siberian Arctic tundra to the west inside the circumpolar tundra belt of the Northern Hemisphere.

<span class="mw-page-title-main">Climate and vegetation interactions in the Arctic</span>

Changing climate conditions are amplified in polar regions and northern high-latitude areas are projected to warm at twice the rate of the global average. These modifications result in ecosystem interactions and feedbacks that can augment or mitigate climatic changes. These interactions may have been important through the large climate fluctuations since the glacial period. Therefore it is useful to review the past dynamics of vegetation and climate to place recent observed changes in the Arctic into context. This article focuses on northern Alaska where there has been much research on this theme.

Susan M. Natali is an American ecologist. She is the Arctic program director and senior scientist at the Woodwell Climate Research Center, where her research focuses on the impact of climate change on terrestrial ecosystems, primarily on Arctic permafrost. She is also the project lead for Permafrost Pathways, a new initiative launched in 2022 with funding from TED's Audacious Project. On Monday, April 11, 2022, Dr. Natali gave a TED Talk introducing the Permafrost Pathways project at the TED2022 conference in Vancouver, BC.

<span class="mw-page-title-main">Tundra of North America</span>

The Tundra of North America is a Level I ecoregion of North America designated by the Commission for Environmental Cooperation (CEC) in its North American Environmental Atlas.

References

  1. "Ecoregions". World Wildlife Fund. Archived from the original on 4 June 2011.
  2. Aapala, Kirsti. "Tunturista jängälle" [From fell to mountain] (in Finnish). Archived from the original on 1 October 2006. Retrieved 17 January 2024.
  3. 1 2 3 4 "The Tundra Biome". The World's Biomes. University of California, Berkeley. Archived from the original on 22 July 2023. Retrieved 5 March 2006.
  4. "Terrestrial Ecoregions: Antarctica". Wild World. National Geographic Society. Archived from the original on 5 August 2011. Retrieved 2 November 2009.
  5. "Tundra Biome". education.nationalgeographic.org. Retrieved 4 April 2024.
  6. "Tundra: Mission: Biomes". earthobservatory.nasa.gov. 4 April 2024. Retrieved 4 April 2024.
  7. 1 2 "The tundra biome". University of California Museum of Paleontology . Retrieved 11 September 2020.
  8. Higuera, Philip E.; Chipman, Melissa L.; Barnes, Jennifer L.; Urban, Michael A.; et al. (December 2011). "Variability of tundra fire regimes in Arctic Alaska: millennial-scale patterns and ecological implications". Ecological Applications . 21 (8): 3211–3226. Bibcode:2011EcoAp..21.3211H. doi:10.1890/11-0387.1. ISSN   1051-0761.
  9. "Great Plain of the Koukdjuak". Ibacanada.com. Retrieved 16 February 2011.
  10. 1 2 "Tundra". Lake Clark National Park & Preserve. NPS. Retrieved 18 October 2021.
  11. "Where Are Arctic Mosquitoes Most Abundant in Greenland and Why?". Ecological Society of America. 4 August 2020.
  12. "Tundra". Blue Planet Biomes. Retrieved 5 March 2006.
  13. "Tundra Threats". National Geographic . Archived from the original on 7 December 2008. Retrieved 3 April 2008.
  14. Gillis, Justin (16 December 2011). "As Permafrost Thaws, Scientists Study the Risks". The New York Times . Retrieved 17 December 2011.
  15. Mack, Michelle C.; Bret-Harte, M. Syndonia; Hollingsworth, Teresa N.; Jandt, Randi R.; et al. (28 July 2011). "Carbon loss from an unprecedented Arctic tundra wildfire" (PDF). Nature . 475 (7357): 489–492. Bibcode:2011Natur.475..489M. doi:10.1038/nature10283. PMID   21796209. S2CID   4371811. Archived from the original (PDF) on 14 November 2012. Retrieved 20 July 2012.
  16. 1 2 Douglas, Thomas A.; Turetsky, Merritt R.; Koven, Charles D. (24 July 2020). "Increased rainfall stimulates permafrost thaw across a variety of Interior Alaskan boreal ecosystems". npj Climate and Atmospheric Science. 3 (1): 5626. Bibcode:2020npCAS...3...28D. doi: 10.1038/s41612-020-0130-4 .
  17. Nowinski NS, Taneva L, Trumbore SE, Welker JM (January 2010). "Decomposition of old organic matter as a result of deeper active layers in a snow depth manipulation experiment". Oecologia. 163 (3): 785–92. Bibcode:2010Oecol.163..785N. doi:10.1007/s00442-009-1556-x. PMC   2886135 . PMID   20084398.
  18. Schuur, E.A.G., Bockheim, J., Canadell, J.G., Euskirchen, E., Field, C.B., Goryachkin, S.V., Hagemann, S., Kuhry, P., Lafleur, P.M., Lee, H., Mazhitova, G., Nelson, F.E., Rinke, A., Romanovsky, V.E., Skiklomanov, N., Tarnocai, C., Venevsky, S., Vogel, J.G., and Zimov, S.A. (2008). "Vulnerability of Permafrost Carbon to Climate Change: Implications for the Global Carbon Cycle". BioScience. 58 (8): 701–714. doi: 10.1641/B580807 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  19. Lim, Artem G.; Loiko, Sergey V.; Pokrovsky, Oleg S. (10 January 2023). "Interactions between organic matter and Fe oxides at soil micro-interfaces: Quantification, associations, and influencing factors". Science of the Total Environment. 3: 158710. Bibcode:2023ScTEn.855o8710L. doi: 10.1016/j.scitotenv.2022.158710 . PMID   36099954. S2CID   252221350.
  20. Patzner, Monique S.; Mueller, Carsten W.; Malusova, Miroslava; Baur, Moritz; Nikeleit, Verena; Scholten, Thomas; Hoeschen, Carmen; Byrne, James M.; Borch, Thomas; Kappler, Andreas; Bryce, Casey (10 December 2020). "Iron mineral dissolution releases iron and associated organic carbon during permafrost thaw". Nature Communications. 11 (1): 6329. Bibcode:2020NatCo..11.6329P. doi:10.1038/s41467-020-20102-6. PMC   7729879 . PMID   33303752.
  21. Bockheim, J.G. & Hinkel, K.M. (2007). "The importance of "Deep" organic carbon in permafrost-affected soils of Arctic Alaska". Soil Science Society of America Journal. 71 (6): 1889–92. Bibcode:2007SSASJ..71.1889B. doi:10.2136/sssaj2007.0070N. Archived from the original on 17 July 2009. Retrieved 5 June 2010.
  22. Lim, Artem G.; Loiko, Sergey V.; Pokrovsky, Oleg S. (2022). "Sizable pool of labile organic carbon in peat and mineral soils of permafrost peatlands, western Siberia". Geoderma. 409. Bibcode:2022Geode.409k5601L. doi:10.1016/j.geoderma.2021.115601.
  23. Gillis, Justin (16 December 2011). "As Permafrost Thaws, Scientists Study the Risks". The New York Times. Archived from the original on 19 May 2017. Retrieved 11 February 2017.
  24. Schellnhuber, Hans Joachim; Winkelmann, Ricarda; Scheffer, Marten; Lade, Steven J.; Fetzer, Ingo; Donges, Jonathan F.; Crucifix, Michel; Cornell, Sarah E.; Barnosky, Anthony D. (2018). "Trajectories of the Earth System in the Anthropocene". Proceedings of the National Academy of Sciences . 115 (33): 8252–8259. Bibcode:2018PNAS..115.8252S. doi: 10.1073/pnas.1810141115 . ISSN   0027-8424. PMC   6099852 . PMID   30082409.
  25. MacDougall, Andrew H. (10 September 2021). "Estimated effect of the permafrost carbon feedback on the zero emissions commitment to climate change". Biogeosciences. 18 (17): 4937–4952. Bibcode:2021BGeo...18.4937M. doi: 10.5194/bg-18-4937-2021 .
  26. Sayedi, Sayedeh Sara; Abbott, Benjamin W; Thornton, Brett F; Frederick, Jennifer M; Vonk, Jorien E; Overduin, Paul; Schädel, Christina; Schuur, Edward A G; Bourbonnais, Annie; Demidov, Nikita; Gavrilov, Anatoly (1 December 2020). "Subsea permafrost carbon stocks and climate change sensitivity estimated by expert assessment". Environmental Research Letters. 15 (12): B027-08. Bibcode:2020AGUFMB027...08S. doi: 10.1088/1748-9326/abcc29 . ISSN   1748-9326. S2CID   234515282.
  27. Hugelius, Gustaf; Loisel, Julie; Chadburn, Sarah; et al. (10 August 2020). "Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw". Proceedings of the National Academy of Sciences. 117 (34): 20438–20446. Bibcode:2020PNAS..11720438H. doi: 10.1073/pnas.1916387117 . PMC   7456150 . PMID   32778585.
  28. 1 2 Fox-Kemper, B., H.T. Hewitt, C. Xiao, G. Aðalgeirsdóttir, S.S. Drijfhout, T.L. Edwards, N.R. Golledge, M. Hemer, R.E. Kopp, G.  Krinner, A. Mix, D. Notz, S. Nowicki, I.S. Nurhati, L. Ruiz, J.-B. Sallée, A.B.A. Slangen, and Y. Yu, 2021: Chapter 9: Ocean, Cryosphere and Sea Level Change. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L.  Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1211–1362, doi:10.1017/9781009157896.011.
  29. 1 2 Schuur, Edward A.G.; Abbott, Benjamin W.; Commane, Roisin; Ernakovich, Jessica; Euskirchen, Eugenie; Hugelius, Gustaf; Grosse, Guido; Jones, Miriam; Koven, Charlie; Leshyk, Victor; Lawrence, David; Loranty, Michael M.; Mauritz, Marguerite; Olefeldt, David; Natali, Susan; Rodenhizer, Heidi; Salmon, Verity; Schädel, Christina; Strauss, Jens; Treat, Claire; Turetsky, Merritt (2022). "Permafrost and Climate Change: Carbon Cycle Feedbacks From the Warming Arctic". Annual Review of Environment and Resources. 47: 343–371. doi:10.1146/annurev-environ-012220-011847.
  30. Dietz, Simon; Rising, James; Stoerk, Thomas; Wagner, Gernot (24 August 2021). "Economic impacts of tipping points in the climate system". Proceedings of the National Academy of Sciences . 118 (34): e2103081118. Bibcode:2021PNAS..11803081D. doi: 10.1073/pnas.2103081118 . PMC   8403967 . PMID   34400500.
  31. Keen, Steve; Lenton, Timothy M.; Garrett, Timothy J.; Rae, James W. B.; Hanley, Brian P.; Grasselli, Matheus (19 May 2022). "Estimates of economic and environmental damages from tipping points cannot be reconciled with the scientific literature". Proceedings of the National Academy of Sciences. 119 (21): e2117308119. Bibcode:2022PNAS..11917308K. doi: 10.1073/pnas.2117308119 . PMC   9173761 . PMID   35588449. S2CID   248917625.
  32. Dietz, Simon; Rising, James; Stoerk, Thomas; Wagner, Gernot (19 May 2022). "Reply to Keen et al.: Dietz et al. modeling of climate tipping points is informative even if estimates are a probable lower bound". Proceedings of the National Academy of Sciences. 119 (21): e2201191119. Bibcode:2022PNAS..11901191D. doi: 10.1073/pnas.2201191119 . PMC   9173815 . PMID   35588452.
  33. "Carbon Emissions from Permafrost". 50x30. 2021. Retrieved 8 October 2022.
  34. Natali, Susan M.; Holdren, John P.; Rogers, Brendan M.; Treharne, Rachael; Duffy, Philip B.; Pomerance, Rafe; MacDonald, Erin (10 December 2020). "Permafrost carbon feedbacks threaten global climate goals". Biological Sciences. 118 (21). doi: 10.1073/pnas.2100163118 . PMC   8166174 . PMID   34001617.
  35. Armstrong McKay, David; Abrams, Jesse; Winkelmann, Ricarda; Sakschewski, Boris; Loriani, Sina; Fetzer, Ingo; Cornell, Sarah; Rockström, Johan; Staal, Arie; Lenton, Timothy (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points". Science. 377 (6611): eabn7950. doi:10.1126/science.abn7950. hdl: 10871/131584 . ISSN   0036-8075. PMID   36074831. S2CID   252161375.
  36. Armstrong McKay, David (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points – paper explainer". climatetippingpoints.info. Retrieved 2 October 2022.
  37. "Terrestrial Plants". British Antarctic Survey: About Antarctica. Retrieved 5 March 2006.
  38. 1 2 "Antipodes Subantarctic Islands tundra". Terrestrial Ecoregions. World Wildlife Fund. Retrieved 2 November 2009.
  39. 1 2 Longton, R.E. (1988). Biology of Polar Bryophytes and Lichen. Studies in Polar Research. Cambridge University Press. p. 20. ISBN   978-0-521-25015-3.
  40. "Protocol on Environmental Protection to the Antarctic Treaty". British Antarctic Survey: About Antarctica. Retrieved 5 March 2006.
  41. Elliott-Fisk, D.L. (2000). "The Taiga and Boreal Forest". In Barbour, M.G.; Billings, M.D. (eds.). North American Terrestrial Vegetation (2nd ed.). Cambridge University Press. ISBN   978-0-521-55986-7.
  42. Marsman, Floor; Nystuen, Kristin O.; Opedal, Øystein H.; Foest, Jessie J.; Sørensen, Mia Vedel; De Frenne, Pieter; Graae, Bente Jessen; Limpens, Juul (January 2021). Pugnaire, Francisco (ed.). "Determinants of tree seedling establishment in alpine tundra". Journal of Vegetation Science. 32 (1). doi:10.1111/jvs.12948. ISSN   1100-9233.
  43. Körner, Christian (2003). Alpine Plant Life: Functional Plant Ecology of High Mountain Ecosystems. Berlin: Springer. ISBN   978-3-540-00347-2.
  44. Kottek, Markus; Grieser, Jürgen; Beck, Christoph; Rudolf, Bruno; Rubel, Franz (2006). "World Map of the Köppen-Geiger Climate Classification Updated". Meteorol. Z. 15 (3): 259–263. Bibcode:2006MetZe..15..259K. doi:10.1127/0941-2948/2006/0130.
  45. "Tundra". geodiode.com.
  46. Peel, M.C.; Finlayson, B.L.; McMahon, T.A. (2007). "Updated world map of the Köppen-Geiger climate classification". Hydrol. Earth Syst. Sci. 11 (5): 1633–1644. Bibcode:2007HESS...11.1633P. doi: 10.5194/hess-11-1633-2007 . S2CID   9654551.
  47. "Tundra". Earth Observatory. NASA . Retrieved 11 September 2022.
  48. Keuper, F.; Parmentier, F.J.; Blok, D.; van Bodegom, P.M.; Dorrepaal, E.; van Hal, J.R.; van Logtestijn, R.S.; Aerts, R. (2012). "Tundra in the rain: differential vegetation responses to three years of experimentally doubled summer precipitation in Siberian shrub and Swedish bog tundra". Ambio. 41 Suppl 3(Suppl 3) (Suppl 3): 269–80. Bibcode:2012Ambio..41S.269K. doi:10.1007/s13280-012-0305-2. PMC   3535056 . PMID   22864700.
  49. Valerio Giacomini, La Tundra del Gavia, Pubblication out of commerce for Stelvio National Park authority, 1975
  50. "Mount Fuji Facts & Worksheets". Kidskonnect. 25 February 2018. Retrieved 25 February 2018.
  51. "Tundra". Mindat.
  52. "Is Svalbard Tundra or Polar?". Restaurant Norman. Retrieved 3 August 2019.
  53. "Get to know Iqaluit". Arctic Kingdom. 24 July 2020. Retrieved 24 July 2020.
  54. "Utqiagvik, Alaska tours". Alaska Collection.
  55. "Antarctic Islands in the Southern Indian Ocean". World Wild Life. Retrieved 1 April 2022.
  56. "Nuuk". Britannica. Retrieved 2 September 2021.

Further reading