Rewilding

Land-based measures

Blueberries (Vaccinium myrtillus) as part of the vegetation 5 years after forest fire, Mykland, Aust Agder, Norway

Large areas of the Northern and Arctic regions consist of permafrost, almost permanently frozen soil. As global temperatures rise, these permafrost areas are thawing at an ever faster rate. This thawing leads to massive amounts of GHGs being released into the atmosphere, either as CO2 or CH4 in generally dry or wet areas. Because methane is a very potent GHG, the thawing of the permafrost is considered a major tipping point in the climatic system. Permafrost preservation is of the utmost importance because Arctic terrestrial regions alone hold up to 1500 Pg C (Schuur et al. 2015), and although there is large uncertainty about the total amount of emissions from permafrost (Miner et al. 2022), especially when it comes to nonlinear abrupt thawing (Turetsky et al. 2020), significant amounts of carbon release is to be expected as the Northern regions warm.

Natural climate solutions like conservation or restoration can significantly contribute to climate change mitigation efforts (Griscom et al. 2017). One such category of natural climate solutions is re-wilding. The concept is contested, with some scientists even suggesting doing away with the term altogether and replacing it with restoration (Hayward et al. 2019), but is generally used to refer to large scale projects to (re)introduce larger herbivores and predators to ecosystems. Several Re-wilding schemes in the Northern and Arctic region investigate whether it might be feasible and desirable to recreate elements of the environment as it existed during the Pleistocene, so-called Pleistocene re-wilding (Donlan et al. 2006), to preserve parts of the permafrost.

The main re-wilding project in the region is Pleistocene Park, which is located close to the Arctic ocean in the far north of Russia’s Sakha Republic (https://pleistocenepark.ru/). The Park is run by father and son Sergei and Nikita Zimov, and attempts to show the possibility to preserve permafrost, or slow its thaw, by Pleistocene re-wilding in an area that is mostly covered by boreal forest. Controlled experiments and observations at the Park have shown that the introduction of large animals has multiple beneficial climate effects, as it reduces soil temperatures leading to increased winter permafrost thickening, increases bio-productivity and encourages carbon storage, and increases albedo through shrub reduction (Zimov 2005; Fischer et al. 2022). Although it has to be noted that there are still debates on the ultimate effects of re-wilding in terms of ecosystem services in the region, for example with regards to side effects of the removal of shrubs by herbivores, which have also been found to be detrimental to permafrost stability (Nauta et al. 2015).

Technological Readiness Level (TRL)

Medium 2

Pleistocene park already exists, but it only consists of 2,000 hectares and contains a limited number of large herbivores of different species. To be truly effective, the Park would require huge amounts of land and animals. Current Arctic biodiversity levels and ecosystems differ greatly from those in the Pleistocene, particularly when it comes to the presence of megafauna (Olafson and Post, 2018), and Pleistocene re-wilding strategies therefore seek to use various kinds of large herbivores to recreate parts of the previously existent grasslands that extended across vast swaths of the north that are currently covered by taiga forests.///Because many of the larger herbivores would have trouble removing already existing boreal forests, an idea is to bring back the mammoth from extinction, or at least create a modified cold-resistant elephant, and introduce it to the Park. The elephant/mammoth would be a key species because it would be able to bring down trees and could thereby gradually expand the grasslands, a task that is now still being performed by large ex-military vehicles. Although there is still uncertainty when this introduction would take place, the geneticist team at Harvard who are working on it say a first hairy elephant could be born within the next few years (Dutchen, 2021).

Technological Readiness Level (TRL)

A technology with a TRL of 4-6: TRL 4 – validated in lab; TRL 5 – validated in relevant environment; TRL 6 – demonstrated in relevant environment

Scalability

Low 1

The most serious obstacles for a project like Pleistocene Park are its scalability and potential to make a meaningful difference at the required timeframe (Macias-Fauria et al, 2020). Given the huge area that would need to be re-wilded, the reproduction rate of animals is a serious issue, especially for the mega-fauna that would be crucial to the success of the re-wilding due to their ability to remove trees. It is furthermore also not certain that the ecosystem would remain viable in the contemporary and future climate, as conditions are vastly different from how they were during the Pleistocene.

Scalability

Physically unable to scale; sub-linear/logarithmic efficiency of scalability

Timeliness for near-future effects

Low 1

There are large uncertainties over the rate of permafrost melt, and the potential to see sudden massive melt. Given the slow reproduction rate and potential obstacles, it is questionable if rewilding efforts could significantly impact methane release from permafrost in the coming decades.

Timeliness for near-future effects

Implemented too late to make a significant difference

Northern + Arctic potential

High 3

Both experimental research at Pleistocene Park (Fischer et al, 2022; Windirsch et al, 2022) and model studies (Lucas and Enos, 2019) confirm that the approach could be effective, although the efficacy of rewilding remains largely unknown. In any case, the large-scale implementation of such schemes would also impact the region in other ways, as rewilding will have significant side effects (see below).

Northern + Arctic potential

Very detectable impacts in the Arctic, above the global average; technology ideally/preferably located here

Global potential

Medium 2

Permafrost can potentially release massive amounts of GHGs, but it is unsure how much rewilding can credibly be prevented by rewilding.

Global potential

Statistically detectable impacts

Cost - benefit

Low 3

Although the project could bring in significant financing through carbon credits (Macias-Fauria et al, 2020), initial costs of such a project would likely be higher than in some other schemes, especially compared to SAI technologies. It is possible that rewilding could become a source of food, or could have other benefits to biodiversity or to local ecosystems that might reduce costs further. A carbon price of 5$/ton would make an investment in this kind of re-wilding repay over 100 years (Macias-Fauria et al, 2020).

Cost - benefit

Low investment cost compared to the avoided damage cost (e.g., a few %) and/or inexpensive relative to other measures with similar impact

Environmental risks

Medium 2

It is not certain that the newly rewilded ecosystem would remain viable in the contemporary and future climate, as conditions are vastly different from how they were during the Pleistocene. The region is already becoming increasingly vulnerable to wildfires, and it has to be studied how this would affect it. Moreover, mass-scale rewilding would cause radical changes in ecosystems, which will have widespread consequences (Rubenstein et al, 2006). However, as these are all “natural” interventions, such risks are potentially less objectionable than those caused by artificial measures.

Environmental risks

More widespread and possibly regional impacts that extend beyond the immediate solution deployment location

Community impacts

Unknown 0

There has been little attention to possible effects on local and indigenous communities. Pleistocene rewilding strategies would seek to be, what Fraanje and Garnett (2022) call land sparing, meaning that it would seek to have as little human presence as possible. Certain side benefits could occur, as has been postulated in the case of rewilding in Finland (Koninx, 2019).

Ease of reversibility

Medium 2

Probably massive rewilding would need to be highly managed for a long time until herds become self-sustaining and can expand. There have however been many examples throughout history where human introduction in ecosystems has led to runaway consequences.

Ease of reversibility

Possible with significant investment

Risk of termination shock

Low 3

Risk of termination shock

Low or insignificant termination shock or damage

Legality/governance

High 3

It is likely that nation states could implement such measures on their own territory.

Legality/governance

Currently legal to deploy, with governance structures in place to facilitate it and/or financial incentives to develop it

Scientific/media attention

High 3

The mammoth-cloning-plan has, unsurprisingly, generated quite some public media interest and has led to several documentaries and a whole swath of newspaper coverage and articles. The de-extinction has also led to criticism from an ethical standpoint (Sandler, 2014). But in general, a main advantage for the reputation of Pleistocene re-wilding as practiced at Pleistocene Park is that it uses natural, low-tech measures that would likely be less objectionable than more technological and invasive technologies. At the Park there has been serious research on the effect of herbivores on permafrost. However, it is unsure what the effects of Russia’s invasion of Ukraine will have on the long term feasibility of this project.

Scientific/media attention

Numerous scientific papers with substantial funding and ongoing research groups; significant media attention and "hype"; many companies exploring commercialization options

References

Josh Donlan, C., Berger, J., Bock, C. E., Bock, J. H., Burney, D. A., Estes, J. A., ... & Greene, H. W. (2006). Pleistocene rewilding: an optimistic agenda for twenty-first century conservation. The American Naturalist, 168(5), 660-681. https://doi.org/10.1086/508027

Dutchen, S, (2021), A Mammoth Solution Scientists look to extinct genes to protect endangered species, climate. Harvard Medical School News, November 12, 2021 https://hms.harvard.edu/news/mammoth-solution

Fischer, W., Thomas, C. K., Zimov, N., & Göckede, M. (2022). Grazing enhances carbon cycling but reduces methane emission during peak growing season in the Siberian Pleistocene Park tundra site. Biogeosciences, 19(6), 1611-1633. https://doi.org/10.5194/bg-19-1611-2022

Fraanje, W., & Garnett, T. (2022). Rewilding and its implications for agriculture. TABLE Explainer Series. TABLE, University of Oxford, Swedish University of Agricultural Sciences and Wageningen University and Research. https://doi.org/10.56661/2aa26681

Griscom, B. W., Adams, J., Ellis, P. W., Houghton, R. A., Lomax, G., Miteva, D. A., ... & Fargione, J. (2017). Natural climate solutions. Proceedings of the National Academy of Sciences, 114(44), 11645-11650. https://doi.org/10.1073/pnas.1710465114

Hayward, M. W., Scanlon, R. J., Callen, A., Howell, L. G., Klop-Toker, K. L., Di Blanco, Y., ... & Weise, F. J. (2019). Reintroducing rewilding to restoration–Rejecting the search for novelty. Biological conservation, 233, 255-259. https://doi.org/10.1016/j.biocon.2019.03.011

Koninx, F. (2019). Ecotourism and rewilding: The case of Swedish Lapland. Journal of Ecotourism, 18(4), 332-347. https://doi.org/10.1080/14724049.2018.1538227

Lucas, Z., & Enos, J. (2019). Modeling the Impact of the Pleistocene Park with System Dynamics. Proceedings of the Annual General Donald R. Keith Memorial Conference. West Point, New York, USA
May 2, 2019. A Regional Conference of the Society for Industrial and Systems Engineering. Available at: http://www.ieworldconference.org/content/WP2019/Papers/GDRKMCC-19_26.pdf [Accessed 19 July 2024]

Macias-Fauria, M., Jepson, P., Zimov, N., & Malhi, Y. (2020). Pleistocene Arctic megafaunal ecological engineering as a natural climate solution?. Philosophical Transactions of the Royal Society B, 375(1794), 20190122. https://doi.org/10.1098/rstb.2019.0122

Miner, K. R., Turetsky, M. R., Malina, E., Bartsch, A., Tamminen, J., McGuire, A. D., ... & Miller, C. E. (2022). Permafrost carbon emissions in a changing Arctic. Nature Reviews Earth & Environment, 3(1), 55-67. https://doi.org/10.1038/s43017-021-00230-3

Nauta, A., Heijmans, M., Blok, D. et al. Permafrost collapse after shrub removal shifts tundra ecosystem to a methane source. Nature Clim Change 5, 67–70 (2015). https://doi.org/10.1038/nclimate2446

Olofsson Johan and Post Eric 2018 Effects of large herbivores on tundra vegetation in a changing climate, and implications for rewilding Phil. Trans. R. Soc. B3732017043720170437. https://doi.org/10.1098/rstb.2017.0437

Popov, I. (2020). The current state of Pleistocene Park, Russia (An experiment in the restoration of megafauna in a boreal environment). The Holocene, 30(10), 1471-1473. https://doi.org/10.1177/0959683620932975

Rubenstein, D. R., Rubenstein, D. I., Sherman, P. W., & Gavin, T. A. (2006). Pleistocene Park: Does re-wilding North America represent sound conservation for the 21st century?. Biological Conservation, 132(2), 232-238. https://doi.org/10.1016/j.biocon.2006.04.003

Sandler, R. (2014). The ethics of reviving long extinct species. Conservation Biology, 28(2), 354-360.https://doi.org/10.1111/cobi.12198

Schuur E et al.2015 Climate change and the permafrost carbon feedback. Nature 520, 171-179. https://doi.org/10.1038/nature14338

Turetsky, M. R., Abbott, B. W., Jones, M. C., Anthony, K. W., Olefeldt, D., Schuur, E. A., ... & McGuire, A. D. (2020). Carbon release through abrupt permafrost thaw. Nature Geoscience, 13(2), 138-143. https://doi.org/10.1038/s41561-019-0526-0

Zimov, S. A. (2005). Pleistocene park: return of the mammoth's ecosystem. Science, 308(5723), 796-798. https://doi.org/10.1126/science.1113442

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