/ 15 June 2021

Tackle climate change and biodiversity loss together, not separately, scientists say

Biodiversity Takes Centre Stage
Lapalala Wilderness School teaches children in Limpopo about biodiversity and how to take care of the environment.

Fifty of the world’s leading climate and biodiversity experts, including scientists from South Africa, have called on global leaders to simultaneously address the intertwined threats of climate change and biodiversity loss.  

The call was made in a new report, in which the scientists say the threats “mutually reinforce each other” and will not be successfully resolved unless both are tackled together. 

The report is the result of the first collaboration of scientists from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) and the Intergovernmental Panel on Climate Change (IPCC). It aims to influence policy decisions that will be taken at the United Nations conference on biodiversity in Kunming, China, in October, and at the UN climate talks in November in Glasgow, Scotland. 

The report is the result of a four-day virtual workshop in December, held by IPBES and the IPCC, where the team of scientists examined the synergies and trade-offs between biodiversity protection and climate change mitigation and adaptation.

Unprecedented changes in climate and biodiversity, driven by people’s activities, have combined and increasingly threaten nature, lives, livelihoods and well-being around the world, the report states. 

And some climate adaptation and mitigation projects end up harming nature and people. 

This includes planting trees in ecosystems that have not historically been forests, and reforestation with plantations, especially with exotic tree species. This is damaging to biodiversity, food production and may displace local people through competition for land.

Professor Guy Midgley, a biodiversity and global change specialist at Stellenbosch University, who is one of the authors of the report, says there are deep links between climate change and the loss of nature. “Some of the real threats emerge when you look at these things together, particularly for Africa. One of the big threats is the rush to fix carbon out of the atmosphere using afforestation: planting lots and lots of trees. 

“That is a (climate) mitigation response that a lot of companies and northern hemisphere countries would like to accelerate and support. When you look at what might happen on the ground if that were to to be implemented in parts of Africa in which we can grow trees, but in which we’d prefer not to because they are game parks or grasslands, which yield water, then you really see the risks, and you only see that when you look at those things together. 

“Planting trees over these areas would be terribly bad for climate adaptation because they would dry up water yields in these areas, exacerbating the climate change impacts that are predicted,” he says. 

Emma Archer, an associate professor in geography and environmental studies at the University of Pretoria, and an author of the report, says it signals a turning point.

“The report is a game changer in the sense that while there is some overlap between the communities working on climate change and the communities working on biodiversity, they have often been treated separately,” she says.

“One of the key areas of learning for us in South Africa, and on the African continent more broadly, is that a healthy ecosystem isn’t simply a luxury or a ‘nice to have’. It is the fundamental basis for supporting adaptation to climate change [among other important services].”

A key example locally is the role of agrobiodiversity in agriculture. “We are increasingly recognising that biodiversity, including genetic diversity, is a critical tool in helping agriculture to adapt both to current climate variability and future climate change.”

Genetic diversity can help support some species in adapting to drought, heat stress and pests and pathogens, Archer says, pointing to rooibos and the use of heritage livestock breeds like Nguni cattle.

“In the case of Nguni cattle, they are an example of a heritage breed with high(er) genetic diversity, and thus, they tend to be a bit more resilient. There is a trend of research that shows that heritage breeds, whether in crops or livestock, are often more resilient — for example, to higher temperatures and disease. This shows how genetic diversity is a critical tool in adapting agriculture to future climate change.”

The report says any measures that focus too narrowly on climate mitigation should be evaluated in terms of  their overall benefits and risks, including some renewable energies generating surges of mining activity or consuming large amounts of land. 

Building dams and sea walls to adapt to climate change, too, can have large negative environmental and social effects, such as interference with migratory species and habitat fragmentation.

Eliminating subsidies that support deforestation, over-fertilisation and overfishing can benefit climate change mitigation and adaptation, with other approaches including changing individual consumption patterns, cutting loss and waste, and shifting diets, particularly in rich countries, towards more plant-based foods.

Hans-Otto Pörtner, co-chair of the workshop’s steering committe, said in a statement, “The warmer the world gets, the less food, drinking water and other key contributions nature can make to our lives, in many regions. Changes in biodiversity, in turn, affect climate, especially through impacts on nitrogen, carbon and water cycles.”

A sustainable global future for people and for nature is still achievable, he says, but “requires transformative changes with rapid and far-reaching actions of a type never before attempted, building on ambitious emissions reductions”. 

This includes moving away from the concept of economic progress based solely on GDP growth, “to one that balances human development with multiple values of nature for a good quality of life, while not overshooting biophysical and social limits”.

The report says valuable approaches to address biodiversity loss and climate change include halting the loss and degradation of carbon and species-rich ecosystems on land and in the ocean, particularly forests, wetlands, peatlands, grasslands and savannahs; coastal ecosystems such as mangroves, salt marshes, kelp forests and seagrass meadows and deep water and polar blue carbon habitats.

Restoration is one of the cheapest and fastest nature-based climate mitigation measures, while increasing sustainable agricultural and forestry practices improve the capacity to adapt to climate change, enhance biodiversity, increase carbon storage and reduce emissions. 

The planet, Midgley says, doesn’t come with an operating manual. “And we need one. We need to understand because we are now so dominant, we’ve become a geological force on the planet …. The science of ecology, biodiversity science and climate change science is developing the ideas that help us understand what are the safe operating limits. 

“And it’s reports like these that translate all that science into messages that can be substantiated at different levels of certainty and uncertainty, that are presented to the policy-making fraternity, without making any value judgments — that these are the facts.” 

The report is dedicated to Bob Scholes, who was at the Global Change Institute at the University of the Witwatersrand,. He died in April. 

“When contacted as a potential co-chair [of the scientific steering committee of the workshop] Bob enthusiastically accepted. He immediately saw the importance of further bringing together the scientific community around biodiversity and climate change, to inspire policymakers in addressing these two issues together,” the report states.