Wild animals can help us capture and store carbon. Here’s how

The ocean, soil and forests are the world’s largest natural carbon sinks. Maintaining and enhancing them is a priority when it comes to halting climate change. However, the importance of wild animals for the carbon cycle may have been underestimated – until now.

A paper published in Nature has compiled evidence “that protecting and restoring wild animals and their functional roles can enhance natural carbon capture and storage”.

Alongside transitioning to renewable energies and preventing a further loss of ecosystems that store CO2, natural climate solutions are held up as cost-effective and sustainable ways of capturing excess CO2. These approaches include protecting and restoring natural ecosystems such as forests, wetlands and coastal areas.

However, even with all these measures working at their best, there will be a shortfall. The authors argue that putting more emphasis on protecting certain animals – like terrestrial and marine mammals and marine fish – could boost carbon storage to fill this gap.

The paper points to research in the tropical rainforest that showed how a greater diversity of animals with medium-to-large bodies and various functional roles can significantly increase carbon absorption. Among the functional roles wild animals fulfil are dispersing the seeds of trees with carbon-dense wood, enhancing the nutrient supply of the soil and controlling the competition between different plants.

When the wildebeest population in Africa dropped dramatically in the wake of a rinderpest epidemic that had transferred from domestic cattle, there were too few animals to fully graze the Serengeti on their migration. With more grass left, the incidence of wildfires increased, releasing large amounts of CO2.

The paper therefore argues that animal conservation must be put into the service of carbon capture and storage more actively.

Animals need to be protected and restored to achieve numbers that enable them to play their functional roles and their part in the carbon cycle effectively. This is also known as “trophic rewilding”.

Between protecting and restoring relevant species – including wildebeest, sea otters, some shark species, elephants, bison and Baleen whales – an extra 6.41 gigatonnes of CO2 per year could be taken out of the atmosphere, the authors say.

While a cost-effective and sustainable approach, extending nature-based solutions to include wild animals is not without its challenges. The authors note that the interactions between these species and both the natural and the human environment need to be weighed up. Grey wolves can have a positive impact on CO2 sequestration in forests, but can badly affect grasslands. Similarly, rewilding large herbivores may positively affect CO2 but release additional methane.

The paper’s authors recommend further research, but not at the risk of missing the opportunities associated with trophic rewilding.

The World Economic Forum actively supports the maintenance and restoration of biodiversity through schemes such as the Biodiversity Finance Initiative. It aims to remove barriers to investor action to help mobilize the estimated average of $844 billion required every year over the next decade to promote biodiversity. Biodiversity finance is trailing climate finance with teething problems such as risk identification and measurement, standardized disclosure and reporting protocols and product design still to be resolved.