Biodiversity and Climate: Flora and Fauna Forced to Adapt to Climate Change

The future of global biodiversity is uncertain in the face of climate change. In a report* published on September 25, 2017, the Academy of Sciences expressed concern about the consequences of climate change on the evolution of animal and plant species. More specifically, its assessment highlights the adaptation mechanisms of flora and fauna in the face of warming—a phenomenon observed throughout the 20th century that is already affecting all levels of ecological organization, from animal and plant populations to ecosystems. Over the course of a century, the impact of this environmental change compounds other disruptions caused by human activities, such as the overexploitation of species, agriculture, livestock farming, deforestation, urbanization, invasive species, and so on.   The Academy of Sciences’ synthesis on the mechanisms by which biodiversity adapts to climate change—and, above all, on the limits of this adaptability—is the result of two years of work. Its objective is to present the current state of scientific knowledge on the subject in order to draw conclusions regarding land management. The first part presents the biological mechanisms of adaptation to climate change, drawing on knowledge from research in ecology, genetics, and physiology of terrestrial and aquatic plant and animal species. The second part shows how ecosystem management and use can take these biological mechanisms into account to minimize the impacts of climate change on biodiversity, but also to make the most of living organisms’ adaptability. The goal is thus to reduce societies’ vulnerability to climate change. Rising temperatures are driving animal and plant species toward the poles or to higher elevations. But what about those that are unable to move? In fact, the ability to adapt to climate change varies greatly: the most specialized organisms with the slowest population growth rates are the least capable of adapting. Furthermore, the diversity of species’ responses to new climatic conditions leads to processes of community restructuring, linked by new interactions. As a result, entirely new species assemblages will soon emerge. Based on the data collected, the report’s authors issue seven recommendations concerning scientific research and the reassessment of environmental, agricultural, and forestry policies. First, they advocate for the development of biodiversity observatories, linked to basic research and scenario modeling. This initiative must be accompanied by training efforts that include the development of skills in animal, plant, and microbiological taxonomy. The contributions of the humanities and social sciences, as well as public education on sustainable development, are considered indispensable. The report also recommends strengthening collaboration among ecologists, historians, archaeologists, and geologists. Above all, in light of the spread of emerging diseases driven by global warming and the global expansion of transportation, public health research and research on the ecology of pathogenic organisms and vectors must converge and be expanded. The academicians also call for environmental management that involves limiting factors contributing to degradation, for example through fishing quotas, marine protected areas, green and blue infrastructure, and so on. According to them, conservation efforts must focus primarily on the most vulnerable species (specialized species, those with low adaptive capacity, slow-growing populations, and megafauna) and on the most sensitive ecosystems (wetlands, marine environments, biodiversity hotspots, etc.). The report must now convince the government. * Report by the Academy of Sciences: “Mechanisms of Biodiversity Adaptation to Climate Change and Their Limits”