Study Provides Solutions To Climate And Biodiversity Crises

Climate change, together with the intensive use and destruction of natural ecosystems, has triggered an unprecedented progressive loss of species. However, the climate and biodiversity crises are often treated as separate disasters. An international team of researchers, in which the Karlsruhe Institute of Technology (KIT) is also involved, is now calling for a rethink: In their overview study published in the journal Science, they emphasize the urgency of staying as close as possible to the 1.5 degree target, and support, among other things, the plan to protect at least 30 percent of land, freshwater and ocean areas. (DOI: 10.1126/science.abl4881 )

The man-made climate crisis has consequences for the entire planet – for example, the distribution of precipitation is shifting, global sea levels are rising, extreme weather events are becoming more frequent and the oceans are becoming increasingly acidic. At the same time, the loss of animal and plant species is progressing worldwide.

“It is imperative that we think of climate protection and species protection together. Because measures that focus solely on climate protection, for example, can also have a negative impact on biodiversity,” says Professor Almut Arneth from the Institute for Meteorology and Climate Research – Atmospheric Environmental Research, the KIT Campus Alpin in Garmisch-Partenkirchen, and co-author of the Study. “Both systems only work together. Healthy ecosystems rich in species and functions, for example, make a major contribution to mitigating climate change.”

According to the review study, human activities have severely altered around 75 percent of the land surface and 66 percent of the ocean areas of the earth. Habitat destruction and overexploitation are putting more species at risk of extinction than at any time in human history, compounded by climate change. Warming and the destruction of natural habitats are also reducing the carbon storage capacity of organisms, soils and sediments, which in turn exacerbates the climate crisis, the researchers said. Because organisms have certain tolerance windows for environmental conditions such as temperature, species habitats are shifting or disappearing as a result of global warming.

Renaturation reduces species extinction and binds CO 2

In order to counteract the climate and biodiversity crisis, the researchers propose an action package consisting of emission reduction, renaturation and protection measures, intelligent management of usable land and cross-institutional political competencies. “Of course, the massive reduction in greenhouse gas emissions and compliance with the 1.5-degree target are still right at the top of the list of priorities,” says Professor Hans-Otto Pörtner from the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research and lead author of the study. In addition, at least 30 percent of land, freshwater and ocean areas would have to be protected or restored to avoid the greatest loss of biodiversity and to maintain the functionality of natural ecosystems. This also helps in the fight against climate change.

According to the study, an extensive renaturation of 15 percent of the areas converted to farmland could already be enough to prevent 60 percent of the extinction events that are still to be expected. In addition, up to 300 gigatons of carbon dioxide could be removed from the atmosphere and bound in the long term, which would correspond to 12 percent of the total carbon emitted since the beginning of the industrial age.

Sustainable measures conserve resources, secure the food supply and increase CO 2 absorption

Furthermore, the authors of the study suggest that protected areas should not be understood as isolated life rafts for biodiversity, but as part of a network that connects areas with semi-natural wilderness via migration corridors. Above all, it is important to involve indigenous societies in protection management and to provide them with state support. In agriculture and fisheries, it is about the sustainable use of land that conserves resources and secures the food supply. Concepts that lead to increased carbon dioxide absorption and carbon sequestration in biomass and soil are to be preferred. At the same time, it is about creating refuges for species that make the yield possible in the first place, such as insects that pollinate fruit trees.

In order for the global biodiversity, climate and sustainability goals planned for 2030 and 2050 to be achieved, climate protection, biodiversity conservation and social benefits for the local population must be considered together in all measures, the study concludes.

The study is the result of a workshop jointly conducted by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) and the Intergovernmental Panel on Climate Change (IPPC), both also known as the “World Biodiversity Council” and “World Climate Council”.