Arctic methane release is the release of

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...

from seas and soils in permafrost regions of the

Arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, N ...

. While it is a long-term natural process, methane release is exacerbated by

global warming In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

. This results in a positive feedback cycle, as

is itself a powerful greenhouse gas. The Arctic region is one of the many natural sources of the greenhouse gas methane. Global warming accelerates its release, due to both release of methane from existing stores, and from methanogenesis in rotting biomass. Large quantities of methane are stored in the Arctic in natural gas

deposits A deposit account is a bank account maintained by a financial institution in which a customer can deposit and withdraw money. Deposit accounts can be savings accounts, current accounts or any of several other types of accounts explained below. ...

, permafrost, and as undersea

clathrates A clathrate is a chemical substance consisting of a lattice that traps or contains molecules. The word ''clathrate'' is derived from the Latin (), meaning ‘with bars, latticed’. Most clathrate compounds are polymeric and completely envelop t ...

. Permafrost and clathrates degrade on warming, thus large releases of methane from these sources may arise as a result of global warming. Other sources of methane include submarine

talik A talik is a layer of year-round unfrozen ground that lies in permafrost areas. In regions of continuous permafrost, taliks often occur underneath shallow thermokarst lakes and rivers, where the deep water does not freeze in winter and thus the ...

s, river transport, ice complex retreat, submarine permafrost and decaying gas hydrate deposits. Methane concentrations are 8–10% higher in the Arctic than in the Antarctic atmosphere. During cold glacier epochs, this gradient decreases to practically insignificant levels. Land ecosystems are considered the main sources of this asymmetry, although it has been suggested in 2007 that "the role of the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...

is significantly underestimated." Soil temperature and moisture levels have been found to be significant variables in soil methane fluxes in

tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...

environments.

Contribution to climate change

Due to the relatively short lifetime of atmospheric methane, its global trends are more complex than those of

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

. NOAA annual records have been updated since 1984, and they show substantial growth during the 1980s, a slowdown in annual growth during the 1990s, a plateau (including some years of declining atmospheric concentrarions) in the early 2000s and another consistent increase beginning in 2007. Since around 2018, there has been a consistent acceleration in annual methane increases, with the 2020 increase of 15.06

parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...

breaking the previous record increase of 14.05 ppb set in 1991, and 2021 setting an even larger increase of 18.34 ppb. While these trends alarm climate scientists, with some suggesting that they represent a

climate change feedback Climate change feedbacks are important in the understanding of global warming because feedback processes amplify or diminish the effect of each climate forcing, and so play an important part in determining the climate sensitivity and future c ...

increasing natural methane emissions well beyond their preindustrial levels, there is currently no evidence connecting the Arctic to this recent acceleration. In fact, a 2021 study indicated that the role of the Arctic was typically overerestimated in global methane accounting, while the role of tropical regions was consistently underestimated. It suggested that tropical wetland methane emissions were the culprit behind the recent growth trend, and this hypothesis was reinforced by a 2022 paper connecting tropical terrestrial emissions to 80% of the global atmospheric methane trends between 2010 and 2019. However, the Arctic's role in global methane trends is considered very likely to increase in the future.

Loss of permafrost

Arctic sea ice

A 2015 study concluded that Arctic sea ice decline accelerates methane emissions from the Arctic

, with the emissions for 2005-2010 being around 1.7 million tonnes higher than they would have been with the sea ice at 1981–1990 levels. One of the researchers noted, "The expectation is that with further sea ice decline, temperatures in the Arctic will continue to rise, and so will

emissions from northern wetlands."

Clathrate breakdown

Ice sheets

A 2014 study found evidence for methane cycling below the ice sheet of the Russell Glacier, based on subglacial drainage samples which were dominated by Pseudomonadota. During the study, the most widespread surface melt on record for the past 120 years was observed in Greenland; on 12 July 2012, unfrozen water was present on almost the entire ice sheet surface (98.6%). The findings indicate that methanotrophs could serve as a biological methane sink in the subglacial ecosystem, and the region was, at least during the sample time, a source of

atmospheric methane Atmospheric methane is the methane present in Earth's atmosphere. Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth's atmosphere. Atmospheric methane is rising. The 20-year globa ...

. Scaled dissolved methane flux during the 4 months of the summer melt season was estimated at 990 Mg CH₄. Because the Russell-Leverett Glacier is representative of similar Greenland outlet glaciers, the researchers concluded that the Greenland Ice Sheet may represent a significant global methane source. A study in 2016 concluded that

methane clathrate Methane clathrate (CH4·5.75H2O) or (8CH4·46H2O), also called methane hydrate, hydromethane, methane ice, fire ice, natural gas hydrate, or gas hydrate, is a solid clathrate compound (more specifically, a clathrate hydrate) in which a large amo ...

s may exist below Greenland's and Antarctica's ice sheets, based on past evidence.

Mitigation strategies

ARPA-E ARPA-E, or Advanced Research Projects Agency–Energy is a United States government agency tasked with promoting and funding research and development of advanced energy technologies. It is modeled after the Defense Advanced Research Projects Agenc ...

has funded a research project from 2021-2023 to develop a "smart micro-flare fleet" to burn off methane emissions at remote locations. A 2012 review article stated that most existing technologies "operate on confined gas streams of 0.1% methane", and were most suitable for areas where methane is emitted in pockets. If Arctic oil and gas operations use Best Available Technology (BAT) and Best Environmental Practices (BEP) in petroleum gas flaring, this can result in significant methane emissions reductions, according to the

Arctic Council The Arctic Council is a high-level intergovernmental forum that addresses issues faced by the Arctic governments and the indigenous people of the Arctic. At present, eight countries exercise sovereignty over the lands within the Arctic Circle ...

. Mitigation of methane emissions has greatest potential to preserve Arctic sea ice if it is implemented within the 2020s.

References

External links

Arctic Methane Emergency Group
UK Based 'Arctic Methane Emergency Group' calling for

action Action may refer to: * Action (narrative), a literary mode * Action fiction, a type of genre fiction * Action game, a genre of video game Film * Action film, a genre of film * ''Action'' (1921 film), a film by John Ford * ''Action'' (1980 fil ...

on Arctic methane crisis
Last Hours Film
Short film about potential for massive release of arctic methane
Methane Tracker
Online tools to visualize atmospheric methane releases
Film Arctic Methane: Why The Sea Ice Matters
Featuring James Hansen, Peter Wadhams, and Natalia Shakhova
Exclusive new pictures INSIDE Siberian crater
Siberian Times, 2014
Methane emissions at Esieh Lake
Washington Post, 2018
7,000 underground gas bubbles poised to 'explode' in Arctic
Siberian Times, 2017
Climate Change in the Arctic and Model Projections
(Video)
Arctic permafrost is thawing fast. That affects us all.
National Geographic, 2019
Why the Arctic is smouldering
BBC Future, by Zoe Cormier, 2019 {{DEFAULTSORT:Arctic Methane Release Arctic Ocean Climate change feedbacks Effects of climate change Environment of the Arctic Methane Permafrost Greenhouse gas emissions