Trophic Rewilding
A new study published in Nature Climate Change suggests that trophic rewilding – the restoration and protection of animals' functional roles in ecosystems – is an overlooked climate solution.
The reintroduction of just nine species or groups of species (including African forest elephants, American bison, fish, gray wolves, musk oxen, sea otters, sharks, whales and wildebeest) would help limit global warming to less than 1 .5°C (2.7°F) established by the Paris Agreement, explains the study.
Animals play a significant role in how much carbon plants, soils and sediments can capture, as they redistribute seeds and nutrients and disturb the soil by digging, trampling and making burrows.
The study underscores the need for a mindset shift in science and policy to take advantage of wildlife's vast potential, by working closely with local communities to address societal issues that may impact conservation efforts.
When it comes to climate solutions, the first thought may not be the wildebeest. But in the Serengeti, these buffalo-looking antelopes hold the key to carbon capture.
Efforts to rewild the wildebeest population through disease management have been hugely successful, helping to reduce the frequency and intensity of wildfires and restore the Serengeti to a hotbed of carbon.
Trophic rewilding — the restoration and protection of animals' functional roles within ecosystems — is an overlooked solution to climate change, says a new study published this week in the journal Nature Climate Change .
According to the study, the rewilding of just nine species or groups of wildlife (African forest elephants, American bison, fish, gray wolves, musk oxen, sea otters, sharks, whales and wildebeest) would contribute more than 95% of the annual requirement to meet the global goal of extracting 500 billion metric tons of carbon dioxide from the atmosphere by 2100. This would help limit global temperature rise to less than 1.5° Celsius (2.7° Fahrenheit) compared to pre-industrial levels, as envisaged by the Paris Agreement.
“There is huge untapped potential in looking at wildlife conservation as a climate solution,” lead author of the study, Oswald Schmitz, a professor at the Yale School of the Environment, told Mongabay.
Reducing carbon emissions is an indisputable solution to address the global climate crisis, but even if we stopped burning fossil fuels immediately, the planet would continue to warm up due to the excess carbon already trapped in the atmosphere.
"Luckily we have the technology to remove CO2 from the atmosphere," Schmitz said. "It's called nature."
Through their movements and behaviors, animals distribute seeds and nutrients and disturb the soil by digging, trampling and building burrows. All of these actions help plants grow and store more carbon, and can even prevent fires. Wildlife can also help hold carbon in soils and sediments by changing the way microbes and chemicals act within these systems.
For example, an experimental study conducted in a tropical forest in Guyana found that carbon storage in trees and soil increased significantly, from 3.5 to four times, when the number of tree species increased from 10 to 70. However, when the number of mammal species rose from five to 35 in the same lots, carbon storage in trees and soils increased four to five times.
However, tapping into wildlife's vast potential will require 'a shift in mindset within science and policy,' said study co-author Frans Schepers, director general of Rewilding Europe.
The importance of natural climate solutions for achieving the goals of the Paris Agreement and for enhancing biodiversity conservation is recognized by several global initiatives, including the United Nations Climate Action Summit and the Convention on the Global Framework for Biodiversity post-2020. However, current natural climate solutions focus primarily on protecting and restoring ecosystems such as forests and grasslands, neglecting the role animals play in providing nutrients, reducing fire risks and helping plants grow.
"We have urgency as we are losing populations of many animal species even as we discover the extent to which their role in ecosystems may enable carbon capture and storage," Schepers said in a statement.
The study suggests that to successfully reintroduce wildlife to areas where humans live, it's important to work closely with local communities to address the complex social issues that can impact conservation efforts. This may include involving local communities in decision-making and governance processes, taking into account their knowledge, values and attitudes towards reintroduced species, as well as their cultural heritage, land rights and access to natural resources.
"I think there is real potential for synergy between wildlife conservation and carbon storage, [but] I'm wary of such actions being touted as game-changing for global warming," Yadvinder Malhi told New Scientist.
Schmitz agreed, stating that "no solution should be over-hyped."
“Animals by themselves will certainly not solve our climate problem,” he added, but it is certain that by looking at the climate and biodiversity as a whole, “we end up creating a wider range of possible solutions”.
One of the strengths of the rewilding solution , Schmitz explained, is that people feel a connection to the animals.
And I think this is a way to make them feel active protagonists in making a difference on this planet, starting from their back garden, with the animals they know well".