The climate crisis and biodiversity loss are unprecedented issues, and addressing them requires a comprehensive and interconnected approach, according to a new study published in the journal Science.
The study, which gathered input from 62 researchers across 35 countries, was the result of a virtual scientific workshop jointly coordinated by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) and the Intergovernmental Panel on Climate Change (IPCC) in December 2020.
“The climate crisis they themselves caused is likely the greatest challenge that homo sapiens have faced in their 300,000-year history,” said Professor Hans-Otto Pörtner, head of the Integrative Ecophysiology Section at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research.
However, he also noted that another equally dangerous crisis is often overlooked: the dramatic loss of plant and animal species across the planet. The two catastrophes – the climate crisis and biodiversity crisis – are interdependent and mutually amplifying. This is why they should never be seen as two separate things, Pörtner added.
The study revealed sobering figures illustrating the rapid worsening of species loss. Human activities have altered about 75 percent of the land surface and 66 percent of marine waters. This resulted in the loss of approximately 80 percent of mammal biomass and 50 percent of plant biomass.
Global warming and the destruction of natural habitats contribute to biodiversity loss. They reduce the capacity of organisms, soils, and sediments to store carbon, which in turn exacerbates the climate crisis.
As global warming causes species’ habitats to shift, mobile species migrate toward the poles, higher elevations on land, or greater depths in the ocean to find suitable temperatures. Sessile organisms, like corals, face the risk of disappearing entirely. They are caught in a temperature trap, while mobile species could run into climatic dead ends.
To address these crises, the researchers propose a combination of emissions reduction, restoration and protection measures, intelligent land-use management, and promoting cross-institutional competencies among political actors. “Needless to say, a massive reduction of greenhouse-gas emissions and reaching the 1.5-degree target continue to be at the top of the priorities list,” said Pörtner.
Moreover, at least 30 percent of all land, freshwater, and marine zones must be protected or restored to prevent the greatest biodiversity losses and preserve the natural ecosystems’ ability to function. This will help combat climate change. Restoring just 15 percent of converted land use zones could prevent 60 percent of expected extinction events. It would also fix up to 300 gigatonnes of carbon dioxide from the atmosphere long-term.
The study’s authors also call for a modern approach to land-use management. They call for protected areas to become part of a global network on land and sea. These networks would interconnect regions via migration corridors for various species. Supporting Indigenous peoples and local communities in their efforts to protect and restore nature is essential. Also important is focusing on sustainability in agriculture and fishing. We should prioritize resource-conserving concepts and carbon dioxide uptake and fixation in biomass and soils.
Pörtner emphasizes that climate protection, biodiversity preservation, and social advantages for local communities must be pursued simultaneously for future measures. Achieving the global biodiversity, climate, and sustainability targets planned for 2030 and 2050 requires more intensive collaboration between institutions. These include the Convention on Biological Diversity and the United Nations Framework Convention on Climate Change. We urgently need a comprehensive approach to address these interconnected crises.
The climate change crisis is a complex and multifaceted issue that has far-reaching consequences for the Earth and its inhabitants. It is primarily driven by human activities. These include the burning of fossil fuels, deforestation, and industrial processes. All of these release vast amounts of greenhouse gases (GHGs) into the atmosphere. These GHGs, including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), trap heat and cause global temperatures to rise.
Some key aspects of the climate change crisis include:
Since the preindustrial era, the global mean temperature has risen by more than 1.1 degrees Celsius. This increase is primarily due to human activities. The temperature increase has caused various impacts on the Earth’s systems. These harmful impacts include disruptions to ecosystems, shifting weather patterns, and the melting of polar ice caps.
As polar ice caps and glaciers melt due to increased temperatures, sea levels around the world have risen. This threatens coastal communities, ecosystems, and infrastructure, leading to increased flooding, erosion, and saltwater intrusion into freshwater sources.
The absorption of CO2 by the ocean has caused its pH level to drop, making the water more acidic. This poses a significant threat to marine life, particularly to organisms with calcium carbonate shells or exoskeletons, such as coral reefs and shellfish.
Scientists have linked an increase in the frequency and intensity of extreme weather events to climate change. These events include hurricanes, heatwaves, droughts, and heavy rainfall. These events can have devastating impacts on ecosystems, agriculture, infrastructure, and human health.
Climate change is a major driver of species loss, as it alters habitats and forces species to adapt or migrate to new locations. Some species may not be able to adapt quickly enough or find suitable habitats, leading to population declines and even extinction.
Climate change can directly and indirectly affect human health through heat-related illnesses, increased air pollution, and the spread of vector-borne diseases, such as malaria and dengue fever. It also threatens food and water security, which can lead to malnutrition and illness.
Climate change can exacerbate existing social and economic inequalities. Its impacts often disproportionately affect vulnerable communities. This can lead to increased migration, conflicts over resources, and challenges to global security.
Addressing the climate change crisis requires a combination of mitigation and adaptation strategies. Mitigation efforts focus on reducing GHG emissions, such as transitioning to renewable energy sources, increasing energy efficiency, and protecting and restoring forests. Adaptation strategies involve adjusting to the impacts of climate change, such as developing resilient infrastructure, improving water management, and supporting sustainable agriculture practices.
International cooperation, as seen through agreements like the Paris Agreement, is essential for implementing these strategies and limiting global warming to well below 2 degrees Celsius, with an aim to limit the increase to 1.5 degrees Celsius above preindustrial levels.
The biodiversity crisis, sometimes referred to as the sixth mass extinction, refers to the rapid decline in the variety and abundance of plant and animal species across the planet. This crisis is primarily driven by human activities such as habitat destruction, climate change, pollution, overexploitation of resources, and the introduction of invasive species. The loss of biodiversity has significant consequences for ecosystems, human well-being, and the global economy.
Human activities like deforestation, urbanization, and agricultural expansion have led to the destruction and fragmentation of natural habitats. As a result, many species lose their homes or face reduced availability of resources, leading to population declines and, in some cases, extinction.
As previously mentioned, climate change is a significant driver of species loss. Changes in temperature, precipitation patterns, and the frequency of extreme weather events can disrupt ecosystems and force species to adapt, migrate, or face extinction.
Overfishing, hunting, and unsustainable resource extraction can lead to the depletion of species populations. This not only threatens the survival of the targeted species but can also disrupt food chains and the balance of ecosystems.
Contamination of air, water, and soil through industrial processes, agricultural runoff, and waste disposal can harm or kill plants and animals. For instance, chemical pollutants can accumulate in organisms through bioaccumulation and biomagnification, leading to toxic effects.
The introduction of non-native species, either intentionally or accidentally, can result in severe consequences for native species. Invasive species can outcompete native species for resources, introduce diseases, or prey on native species, leading to declines in biodiversity.
The decline of species populations can result in the loss of genetic diversity, making them more vulnerable to environmental changes, diseases, and other threats. This reduced resilience can further contribute to the risk of extinction.
Addressing the biodiversity crisis requires a combination of conservation, restoration, and sustainable management efforts. Some key strategies include:
Establishing and effectively managing protected areas, as well as restoring degraded ecosystems, can help conserve species and maintain ecosystem functions.
Implementing sustainable practices in agriculture, forestry, and fisheries can help reduce the negative impacts of these activities on biodiversity. This includes adopting agroecological practices, reducing deforestation, and enforcing sustainable fishing quotas.
Mitigating climate change through the reduction of greenhouse gas emissions and adaptation measures can help alleviate pressures on biodiversity and ecosystems.
Preventing the introduction and spread of invasive species, as well as managing established invasive populations, can help protect native biodiversity.
Ensuring that biodiversity conservation is considered in policies, land-use planning, and decision-making processes can help promote more sustainable development and reduce the loss of biodiversity.
Enhancing public awareness of the importance of biodiversity and encouraging cooperation among governments, non-governmental organizations, the private sector, and local communities can help drive collective action to address the biodiversity crisis.