Why is biodiversity so important?
The natural environment provides the basic conditions without which humans could not survive. This seems intuitive enough: we need to breathe, eat, drink and shelter ourselves and we get all this from the natural world.
In 2005, the Millennium Ecosystem Assessment (MA), a study involving more than 1,300 scientists worldwide, popularized the concept of “ecosystem services”. It refers precisely to the multitude of resources and processes that are supplied by ecosystems and that are essential to human activity. The MA classified ecosystem services into four categories :
- The provisioning services are the goods provided by the ecosystems such as food, non-fossil fuel, fibres, medicinal plants, …
- The regulating servicesare, for example, the regulation of local and global climate, the prevention of floods and diseases, or the purification of water, …
- The cultural services are the intangible benefits provided by the ecosystems, such as spiritual fulfillment, leisure, esthetics (landscapes), …
- The supporting services are all those services without which the other services could not exist: nutrient cycles, crop pollination, soil formation, primary production (photosynthesis), provision of habitat …
Biodiversity is central to ecosystem functioning and, hence, the existence and maintenance of ecosystems services. For example:
- insects, bats, birds, and other animals serve as pollinators;
- parasites and predators act as natural population controls;
- various organisms, such as earthworms and bacteria, are responsible for recycling organic materials and maintaining the productivity of soils;
- legumes (such as peas, beans and hundreds of other species) fix the atmospheric nitrogen and thus help fertilize soils;
- wetlands serve as sponges to reduce the impacts of floods and to cleanse streams by filtering sediments, nutrients, and contaminants from inflowing waters.
The value of biodiversity and ecosystem services and the cost of inaction
Lately, several initiatives intend to estimate the value of biodiversity and ecosystem services, whether social or economic. The most popular initiative is The Economics of Ecosystems and Biodiversity (TEEB), a “global initiative focused on drawing attention to the economic benefits of biodiversity”. Launched in 2007, it analyses “the global economic benefit of biological diversity, the costs of the loss of biodiversity and the failure to take protective measures versus the costs of effective conservation”.
Here are some examples of the estimated value of biodiversity and ecosystem services:
- Plant-based drugs and medicines are worth US$ 40 billion per year.
- Benefits drawn from coral reefs fisheries and tourism have been estimated to US$30 billion per year.
- Fishing is worth US$ 58 billion per year.
Here are examples of the costs of biodiversity loss and ecosystem degradation:
- The introduction of the zebra mussel in aquatic ecosystems of the USA costs the energy industry $100 million per year in damages and maintenance.
- In the UK, the damages caused by agriculture to other ecosystem services have been estimated to $2.6 billion per year.