Overstating wild animal roles in carbon capture may hinder, rather than facilitate, effective climate-mitigation and conservation efforts.

The two greatest environmental challenges of our time are global climate change and biodiversity loss, and it is attractive to look for synergies that can address both these challenges. This has generated support for nature-based solutions to climate change which, until recently, have largely focused on vegetation restoration and tree planting. However, there are increasing news stories circulating on how conserving and restoring large animal wildlife, such as elephants and whales, can absorb carbon and bring climate change mitigation benefits. This sounds very attractive: potential carbon could bolster much-needed funding for conservation and rewilding. What’s not to like?

In this opinion piece in Nature Climate Change we inject a voice of caution into this story. The science around wildlife providing climate benefits is generally weak and very context-dependent – in many cases animal wildlife like savanna elephants may reduce carbon stocks. Many widely reported studies are modelling studies which incompletely capture the many ecological processes at play – actual convincing field-based evidence is very rare – yet such studies get a disproportionate amount of media attention. We show there is very selecting media reporting of the minority of studies that suggest climate benefits of animal wildlife. There is a real danger that claimed climate benefits may not exist, leading to backlash and discrediting of otherwise creditable conservation and rewilding schemes when paid-for carbon benefits do not emerge. Many vibrant ecosystems such as savannas and grasslands can have lower carbon stocks than similar ecologically degraded ecosystems. And excessive focus on carbon can encourage bioperverse outcomes, such as reducing animal wildlife abundance where it is seen to negatively impact carbon stocks. There are both practical and moral dangers around excessive “carbonization” of wildlife that we need to be alert to.