COP28: Trophic Cascading Climate Solutions

RITURAJ PHUKAN

Mahabahu at Cop27 — Rituraj Phukan in COP27

A flurry of recent reports has once again reiterated that reinvigorating the natural systems is central to stopping and reversing the impacts of climate change and biodiversity loss.

At the same time, the window for remediation is shrinking rapidly, with one study warning of total ecosystem collapse and the start of the sixth mass extinction on Earth. Trophic rewilding or reintroduction of species is seen as a critical component of the bucket of natural climate solutions.

The rapid destruction of natural habitats due to human development activities and greed is undermining the global ecosystems that provide us with clean air, water, and food.

Researchers studying the “Great Dying” Permian-Triassic mass extinction, which wiped out 95% of all life on the planet, found that species are currently going extinct faster than in any of the previous five mass extinction periods. Another study found that globally forests and other natural habitats are losing their ability to absorb carbon due to anthropogenic pressures.

On the positive side, one study presents scientific evidence to show that protecting and restoring wild animals and their functional roles can enhance natural carbon capture and storage.

The researchers called for a new thinking that includes the restoration and conservation of wild animals and their ecosystem roles as a key components of natural climate solutions. New research also shows how projects bringing back seabird populations can also bolster ocean ecosystems that sequester carbon.

The Paris Agreement goal of limiting warming to 1.5 C from the pre-industrial levels focuses on reaching net-zero CO2 emissions by transitioning to renewable energy generation by 2050 and stopping deforestation and land conversion to prevent the emissions of carbon already stored in ecosystems.

Current commitments, even if fully implemented, are not enough to limit warming to a catastrophic 2 degrees Celsius. Besides, the heat-trapping capacity of the CO2 that remains in the atmosphere means more measures are required, including ‘negative emissions’ solutions that remove and store up to 500 Gt of atmospheric CO2 by the turn of the century.

The study, “Trophic rewilding can expand natural climate solutions”, points out that while natural climate solutions can arrest climate change by protecting and enhancing carbon capture and storage in plants, soils, and sediments in ecosystems, while also protecting habitats and landscapes to conserve the diversity of wildlife species, we must now pay attention to the role animals play in controlling the carbon cycle.

The authors explain that current natural climate solutions focus on protecting and restoring trees, mangroves and seagrasses, and soil and sediment microbes in ecosystems. However, wild animals, especially terrestrial and marine mammals, and marine fish, also can have consequential effects with a diversity of functional roles in the ecosystem.

The authors of the paper explain that using wild animal conservation explicitly to enhance carbon capture and storage is known as ‘animating the carbon cycle’ and requires the creation of dynamic landscapes. Protecting and restoring the ability of animal species to reach ecologically meaningful densities so that as they move and interact with each other and fulfill their functional roles in ecosystems is known as trophic rewilding.

Recent research in Africa reveals that the extinction of critically endangered elephants would cause the rainforests of central and west Africa to lose between six and nine percent of their ability to capture atmospheric carbon. Elephants and other megaherbivores affect the abundance of forest trees by feeding more heavily on the leaves of low-carbon density trees, often ripping off branches or uprooting a sapling when eating.

High carbon density heavy wood trees grow slowly and produce large nutritious fruits which are eaten by the elephants. The seeds pass through the gut and are excreted all over the forest with dung, which helps the high-carbon trees to flourish.

Due to these preferences, elephants are directly tied to influencing carbon levels in the atmosphere; high-carbon-density trees store more carbon from the atmosphere in their wood than low-carbon-density trees, helping combat global warming.

Other studies corroborate the findings that large herbivores like elephants improve the availability of nutrients to plants and support the storage of carbon in vegetation and soil while making ecosystems more resilient to climate change by dispersing seeds, trampling vegetation, and creating gaps, which enables a variety of plants to grow in the forest. The excretion of dung by large herbivores may also improve the availability of nutrients to plants and support the storage of carbon in vegetation and soil.

Although forests including plantations cover just 9% of the landmass, most natural climate solutions focus largely on forest ecosystems which represent only 14% of the 431 terrestrial and 37 marine ecosystems worldwide. There is huge scope for expansion of natural climate solutions and rewilding, as wild animal species occur in all ecosystems, and the variety of locally relevant, community-led initiatives, depending on the prevalence of diverse species in different regions.

The current focus of trophic rewilding to animate the carbon cycle on larger-bodied wild vertebrates like whales, elephants, bison, tiger, wolves, etc., is because of their larger ecological effects, sensitivity to human exploitation, habitat loss, etc., and because rewilding these require challenging interventions compared to restoring plant biomass and diversity.

The authors also underlined the need to consider the complexities associated with trophic rewilding because some species’ impacts may vary across ecosystems. Another concern is that trophic rewilding of large herbivores will increase methane release unless it occurs with measured reductions in domestic livestock.

Trophic rewilding solutions represent the convergence of action to meet the goals of the Paris Agreement, the Global Biodiversity Framework, and the Sustainable Development Goals.

The deployment of natural climate solution projects is an opportunity to address inequalities across regions. There is an urgency for further research, policy changes, and implementation because we are losing populations of many animal species just as we are discovering how much they functionally impact carbon capture and storage.

The return of the great mammals to their historic populations will have trophic cascading impacts and ensure long-term planetary health and human wellbeing.

Rituraj Phukan is an environmental activist and writer based in Assam, a biodiversity rich, climate impacted province in the far east of India. A commerce graduate, he quit his government job to begin a lifelong engagement with nature, travelling, writing and teaching students about the environment, wildlife and climate change. He is Secretary General of Green Guard Nature Organization, a grassroots civil society group working with fringe forest communities to explore and establish sustainable solutions for management of man-animal conflict. He also serves as the Chief Operating Officer of Walk For Water, a group that is leading a global water conservation movement with a mission to provide universal accessibility to safe water. Rituraj is a Climate Reality Leader trained at Istanbul 2013 and is a Mentor and District Manager with The Climate Reality Project India. Rituraj was a member of the International Antarctic Expedition led by Polar explorer Robert Swan, the first man to have walked to both the poles, in 2013, completing a personal leadership and environment sustainability program called ‘Leadership on the Edge.’ He has also travelled to the Canadian Arctic on an Earthwatch expedition called ‘Climate Change at the Arctic’s Edge’ to participate in ongoing citizen science research about the impacts of global warming on the fragile arctic ecosystems, while based at the Churchill Northern Studies Centre. As the Assam Coordinator for Kids For Tigers, the Sanctuary Nature Foundation initiative for students, he works with schools to sensitize students about the connection between tigers, their forest habitat, climate change and conservation needs and consequences.

Rituraj is the Climate Editor of the MAHABAHU English Fortnightly published from Guwahati ( Assam), India

30-11-2023 [Images collected from different sources]

Mahabahu.com is an Online Magazine with collection of premium Assamese and English articles and posts with cultural base and modern thinking. You can send your articles to editor@mahabahu.com / editor@mahabahoo.com (For Assamese article, Unicode font is necessary)