Pamela McElwee, professor in the Department of Human Ecology, is co-author of a new study, “Overcoming the coupled climate and biodiversity crises and their societal impacts,” published in the journal, Science. She is among 18 international experts who contributed to the study.
“This paper emphasizes that biodiversity loss and climate change are essentially two sides of the same coin. But our policies are often designed for either one or the other, but not both. At the minimum, this leads to unnecessary overlap and duplication, but at the worst, it means policies working at cross purposes or even making the situation worse,” said McElwee.
In announcing the study, led by Prof Hans-Otto Pörtner, head of the Integrative Ecophysiology Section at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research and co-chair of the IPCC Working Group 2, the experts describe the rapidly worsening loss of species with the aid of sobering figures: they estimate that human activities have altered roughly 75 percent of the land surface and 66 percent of the marine waters on our planet. This has occurred to such an extent that approximately 80 percent of the biomass from mammals and 50 percent of plant biomass has been lost, while more species are in danger of extinction than at any time in human history.
The destruction of natural habitats not only leads to biodiversity loss, but also reduces the capacity of organisms, soils and sediments to store carbon, which in turn exacerbates the climate crisis. In a vicious catch-22, these degraded ecosystems are then even more vulnerable to rising temperatures. Yet despite these interactions, the study points out that not enough is being done to tackle both problems together.
“It is important to recognize that essentially no country in the world is doing the maximum it could to integrate biodiversity and climate policy, and many countries don’t even acknowledge the impacts of each sector on the other,” explained McElwee.
“This can lead to unnecessary trade-offs, like poorly planned renewable energy installations that encroach on biodiversity-rich protected areas, or promotion of biofuels that can lead to habitat destruction. Considering both climate and biodiversity impacts of our choices together would have helped minimize these trade-offs,” she added.
McElwee has served as one of 50 scientists selected by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) and the Intergovernmental Panel on Climate Change (IPCC) for the first joint workshop report between the two organizations. They met virtually during the pandemic in 2020 and 2021 to assess the state of knowledge around biodiversity and climate change linkages. The distillation of that process was a summary report by the chapter leads that has now been published in Science.
She took a leading role in analyzing the governance and policy changes that would be needed to manage for integrated biodiversity and climate problems. Her research in Southeast Asia on how environmental policies can be designed to maximize social and ecological benefits has helped inform her work on this paper.