Ice sheet stabilization by draining water or bed freezing

Methane is a highly potent greenhouse gas and its reduction is given ever greater priority in international emission reduction policies. Given the increasing, and potentially catastrophic rate of methane release from the thawing Arctic and Northern permafrost, these regions are crucial in this endeavor. Apart from the methane release from microbial activity in thawing permafrost on land, methane also escapes in the form of hydrates which have been formed under sediments beneath the sea.

Oceans play an important role in global heat transfer and carbon storage processes. As global temperatures and atmospheric carbon levels rise, some have suggested artificially modifying the vertical movement of water to enhance these processes.

GHG emissions reductions and future negative emissions are the only sustainable solutions to stabilize or even reverse global warming as they counter the cause of the problem. However, the required actions will likely take time to materialize, and inertia in the climate system and locked-in warming already ensures major changes in global temperatures and the nearing of several tipping points. Solar radiation management (SRM) techniques seek to reduce global temperatures by reflecting incoming solar radiation. They would thereby not fix the underlying issue of the warming effects of GHGs but are, according to the United Nations Environment Programme (UNEP) Review on Solar Radiation Modification Research (2023), 'the only known approach that could be used to cool the Earth within a few years'.

The concentration of GHGs in the atmosphere will have to be stabilized or lowered to mitigate or even reverse current global warming. To achieve this, current GHG emissions need to be reduced. Such mitigation strategies will however take time to deploy, and some emission sources will be difficult to mitigate. Moreover, since current atmospheric levels are already having a major warming effect, negative emission or Carbon Dioxide Removal (CDR) measures that reduce the amount of GHGs in the atmosphere are an active topic of research.

Sea ice can be an effective insulator between colder winter air and the warmer ocean below, thereby reducing the potential dissipation of heat into space.

Arctic sea ice extent has rapidly decreased over the last few decades, with most multi-year ice disappearing altogether. This has already had major effects on local communities and ecosystems. The disappearance of the relatively reflective sea ice also leads to a dramatic decrease of albedo in the Arctic and subsequent high energy uptakes by the darker water during the Arctic summers.

One of the potentially most catastrophic effects of contemporary global warming would be the dramatic increase in sea levels as a result of the melting Greenland and Antarctic ice sheets. Even if all current emissions were immediately stopped, sea level rise could still occur because of lockedin warming (State of the Cryosphere report 2022).

Wetlands and peatlands play important roles in global carbon cycles. Wetlands are areas that are seasonally covered by water. Globally mangroves are often the main topic of focus when it comes to wetlands (IPCC AR6 WG3, 2022, 7.4.2.8). In the Arctic and Northern regions, peatlands are important wetland elements, and will be the focus of what follows. Such peatlands are very carbon rich and store carbon in biomass below and above ground and in soil carbon. Although they only make up 3% of the Earth’s surface, peatlands store up to 21% of terrestrial carbon, and damaged peatlands contribute close to 5% of anthropogenic CO2 emissions (Leifeld et al. 2019). Peatland drainage between 1850 and 2015 has globally already released 80 Gt CO2-eq, and this figure may climb to 250 Gt CO2-eq by 2100 (Leifeld et al. 2019).

Compared to the global state of such areas, Arctic and Northern wetlands and peatlands remain relatively intact (UNEP 2021), and only around 2% of boreal peatlands are currently converted into croplands (Leifeld and Menichetti 2018). However, increasing attention is being paid to the importance of restoring destroyed areas, which make up 78% of total global peatlands, and preserving endangered ones, especially in light of the effects of climate change on such ecosystems. The Resilience and Management of Arctic Wetlands notes (CAFF 2021) therefore highlight the need for increased wetlands resilience to protect against future damage.