Connections Between Biodiversity and Climate Change

Researchers identified five key drivers^[14] of biodiversity loss. These are habitat destruction, invasive species, pollution, an increase in human population, and overexploitation of natural resources. However, climate change is now also considered^[15] a significant cause of biodiversity loss that increases the impact of other factors on nature and human well-being. Indeed, it can change habitat distribution and increase extinctions. Nearly one-third of plant and animal species could face extinction^[16] as a result of climate change. Together, the drivers of biodiversity loss have significantly altered nature^[17] in most parts of the world. Changes related to human activity are particularly significant. Human activity creates conditions for fast biological evolution. Among these activities, land-use change – the modification of natural land for human activities – has had the worst impact on ecosystems since 1970. The exploitation of animals, plants, and other organisms poses another critical threat. This exploitation primarily occurs through harvesting, logging, hunting, and fishing.

Besides the above, pollution is also increasing. Although global trends vary, air, water and soil pollution have continued to rise in some areas. Marine plastic pollution, in particular, has increased over time^[18] . Over 300 million tons of plastic are produced every year, and 14 million tons of plastic end up in the ocean, making up 80% of all marine debris. Marine species ingest or become entangled in plastic debris, causing severe injuries and death^[19] . Plastic pollution is therefore a significant threat to marine life and food safety. It can affect humans through the food chain due to their consumption of animal-based diets that contain plastic components absorbed from polluted environments. Another major risk to biodiversity is through biological invasions. Nearly one-fifth of the Earth’s surface is at risk of plant and animal invasions, impacting native species, ecosystem services, economies and human health. The rate of introduction of new invasive alien species – species that are not native to the area – seems higher than ever before^[20] and shows no signs of slowing. This leads to the invasion of ecosystems and the loss of local diversity, impacting nature and habitats negatively.

Current trends of biodiversity loss and the strain on natural ecosystems further challenge the climate adaptation of vulnerable populations. Land and ocean ecosystems play a crucial role in reducing greenhouse gas emissions, absorbing 54% of human-made emissions in the past decade. Therefore, it is essential to protect these ecosystems to achieve a balance^[21] between the greenhouse gases we produce and remove. But these ecosystems are facing growing threats, pushing the world beyond planetary boundaries. In other words, biodiversity loss is reaching a critical threshold. This could lead to irreversible consequences for the health of the planet and its ecosystems.

This loss of diversity, including genetic diversity (the variety of genetic traits within species), poses a serious risk to global food security. It weakens the resilience of agricultural systems against threats such as pests, pathogens, and climate change. Historical examples, such as the Irish Great Famine (1845-1849), demonstrate^[22] that a lack of crop variety and over-reliance on a few high-yielding varieties can lead to country-wide famines. The Irish Great Famine was caused by reduced genetic variety. Because the same crop was used over and over again, the entire crop species became susceptible to disease. This could have been prevented with more agricultural diversity.

Another more recent example is the sudden drought in western Russia^[23] in the summer of 2010, caused by the heat wave that affected wheat production in the country. As Russia was a major exporter of wheat, this drought led to a number of concerns. These concerns were connected to questions of global food security, self-sufficiency, and a rise in the prices of wheat. Food security thus faces a double-edged sword from both biodiversity loss and climate change. 

Similarly, the healthcare sector faces challenges due to the decline of biodiversity. The pharmaceutical industry relies on a variety of chemical products derived from medicinal plants and microorganisms found in diverse environments. The loss of these resources can affect medical research and the development of treatments. Increasingly, studies are showing that biodiversity and human infectious diseases are intricately linked^[24] . This is because human pressure on biodiversity increases the risk of infectious diseases. Zoonoses – diseases transmitted from other animal species to humans – account for approximately 60% of all infectious diseases and 75% of emerging infectious diseases in humans. This phenomenon is likely to be the direct result of increased contact between humans, wildlife and livestock. These interactions happen more frequently on the frontier of human expansion because of changes to the natural landscape and increased encounters with animals. This is particularly the case in previously human-free forest areas.

There has been a lack of interest from both society and politics in biodiversity protection the world over. Nature is primarily managed by local communities that depend on it for their daily needs. In territories managed by indigenous peoples, nature is generally declining less rapidly as compared to other areas controlled by governments or local authorities. Though the implementation of policies and actions to conserve and preserve nature has progressed, it is not sufficient^[25] to reduce the impact of all drivers of biodiversity loss. Such efforts to preserve biodiversity will only work under two conditions^[26] . Firstly, they need to address the reasons for deforestation, whether they are economic or cultural. Secondly, they must also tackle the dependence of poor people living in rural areas on hunting and trading wild animals.

In 1992, an international summit known as the Rio Earth Summit (or United Nations Conference on Environment and Development) was held. It recognized the equal importance of climate change and biodiversity. At the end of the summit, world leaders adopted^[27] two conventions: the United Nations Framework Convention on Climate Change (UNFCCC) and the Convention on Biological Diversity (CBD). While the UNFCCC focused more on climate mitigation, the CBD looked into conservation and sustainable use of resources. They started on diverging paths, until leaders realized that both were inextricably linked to each other. Being a global issue of greenhouse gas emissions, climate change received more political, scientific, and public attention than biodiversity, which was considered only a national resource. Indeed, climate change was perceived as linked to the health of the economy. Meanwhile, biodiversity was seen as linked to the health of nature. While the economy had long been part of collective consciousness, nature had not. Biodiversity faced a higher risk of being left behind. 

Two solutions to climate change have been in place to protect biodiversity: afforestation (planting trees on land that was not previously forested) and reforestation (planting trees on previously forested land). This was mainly considered a mitigation approach, which involved storing atmospheric carbon in environments where trees can grow fast. However, such approaches never accounted^[28] for biodiversity or promoted its conservation. Instead, it had a negative impact on species and ecosystems. This turned out to be a major gap in climate action. However, in recent years, society realized the importance of protecting nature. As a result, the debate on being nature-positive started to overtake the earlier “forest for storage” thinking.

This has led to concrete progress in the protection of biodiversity. Almost 100 countries have now incorporated biodiversity values into their national accounting systems. The global rate of deforestation has declined by about a third over the past decade. Fishing practices have been efficiently adjusted in some places, leading to an increase in fish stocks. More areas in the world are now officially protected. In concrete terms, the protection of areas of importance for biodiversity has increased^[29] from 29 to 44% over the 2000-2020 period. All these facts point to the increased care for biodiversity among policymakers worldwide.

In order to tackle the issues of climate change and biodiversity together, a few approaches surfaced in recent years. The first such attempt was the introduction of Ecosystem-based adaptation (EbA). EbA is defined^[30] as the use of biodiversity and ecosystem services to adapt to the adverse effects of climate change while strengthening the resilience of communities. Simultaneously under the UNFCCC, the concept of REDD+ emerged in 2007. It stands for “Reducing Emissions from Deforestation and Forest Degradation in Developing Countries and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks”. More recently, the concepts of OECMs (Other Effective Area-Based Conservation Measures) and Nature-based solutions (NbS) came into being. Many EbA and REDD+ approaches are seen as NbS now. All these strategies have a common priority: acting on nature and its resources to solve the climate problem while keeping nature intact. Some more details on these approaches are presented below.

Ecosystem-based approaches to climate change adaptation (EbA)

Ecosystem-based approaches (EbA) are defined by the Convention on Biological Diversity as the use of nature’s services to help communities adapt to the impacts of climate change. It involves^[31] the conservation and restoration of ecosystems, such as forests, wetlands, and coastal areas, to enhance their resilience. This gives us benefits such as flood protection, water regulation, and livelihood support. For instance, one way to do EbA is by improving how we manage forests. Reducing deforestation, preventing forest degradation, and promoting sustainable forest removal can help make forests sustainable. It can enhance carbon storage in trees, thus supporting climate mitigation, but it can also help ecosystems and species survival in the short and long term.     

Other Effective Area-Based Conservation Measures (OECMs)

Other effective area-based conservation measures (OECMs) are places outside of protected areas that promote the conservation of nature on a larger scale. Instead of only focusing on specific parts of nature, like vulnerable habitats or species, OECMs encompass many different aspects of the environment. This may include green infrastructure in cities and territories managed by local and indigenous people. This network beyond protected areas improves the flow of ecosystem services while increasing climate adaptation benefits. 

Reducing emissions from Deforestation and Forest Degradation (REDD+) 

Reducing emissions from deforestation and forest degradation (or REDD+) is a UNFCCC program. Its goal is the promotion of sustainable forest management and conservation. 47 countries are involved. Most of them are developing countries which are engaging in efforts to slow down deforestation and forest degradation. A key goal is to enhance forest carbon stocks (the “+” in REDD+). Brazil’s Amazon Fund is a prominent REDD+ activity. Since 2008, this financial mechanism supports projects in the Amazon rainforest. The fund has attracted important international contributions to promote sustainable development. It has supported a range of causes, including law enforcement, indigenous land rights, and sustainable livelihoods. Sustainable livelihoods mean finding ways for local communities to support themselves without harming the environment in the future. With the Amazon Fund, this means helping communities thrive economically while preserving the rainforest.

Nature-based Solutions (NbS)

Many of the above-mentioned policy approaches now seem to fall under the broad category of NbS. NbS means using the resources of ecosystems to address the challenges posed by climate change. These stakes include^[32] human health, food and water security, and disaster risk reduction. These approaches correspond to policies that protect, manage, or restore these ecosystems. NbS offer multiple benefits at once. They promote human well-being, biodiversity, and climate mitigation and adaptation. Examples include landscape approaches, sustainable agriculture, and ecosystem restoration.

To conclude, Ecosystem-based approaches and OECMs concentrate on ecosystem conservation and restoration, while REDD+ targets the decrease of emissions stemming from deforestation. Nature-based Solutions encompass a broader range of policies and strategies that use ecosystems to tackle climate change and promote multiple benefits simultaneously.