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Bedrock of sustainable development

Background: Decline in biodiversity


Red eft in Pennsylvania, USA

Biodiversity has been declining sharply for several decades. Natural habitats such as forests and coral reefs are being lost. This trend is particularly clear in the 35 areas across the globe described as "biodiversity hotspots".

The facts are alarming. The International Union for Conservation of Nature (IUCN) places almost 30 per cent of its Red List of 86,000 species in the "endangered" category (as at May 2017). Since many species have yet to be discovered or described, the real number of endangered species could be significantly higher. The extinction rate has also risen sharply. And this loss of species is not confined to wild animals and plants. Ancient breeds of domestic animals and cultivated plants are also disappearing because they no longer satisfy the demands of modern farming.

The 2016 State of World Fisheries and Aquaculture report published by the Food and Agriculture Organization of the United Nations (FAO) demonstrates the threat that the fishing industry poses to species diversity in the seas. Over 30 per cent of assessed marine fish stocks were being fished in greater quantities than could be renewed naturally in the same period. This acutely short-sighted industrial practice is a threat to food security and the economic livelihoods of millions of people.

Overuse of natural resources

There are many complex reasons for the rapid decline in biodiversity. The main causes include the excessive pressure on natural resources exerted by the world’s growing population, and the conversion of natural ecosystems into croplands. It is primarily the populations in industrial countries who are consuming more natural resources than our planet’s ecosystems can provide.

In the partner countries where Germany is engaged in development cooperation, many people, primarily those living in poverty, are compelled to make excessive use of natural resources. Clear-cutting, unregulated refuse disposal, water pollution, non-adaptive agricultural management methods and the expansion of road systems and urban infrastructure all destroy natural habitats.

Pressure on natural resources is dramatically increased as a result of unsustainable mineral extraction and the use of forests and farmland for global food and fuel production. Political instability, inequitable distribution of land and a lack of legal standards or established checks and balances accelerate these processes. A vicious circle results wherein poverty leads to environmental destruction, and the resultant loss of the basis for a viable livelihood then leads to increased poverty.


Climate change

Aerial view of the rainforest, Anavilhanas National Park, Brazil

Climate change threatens the delicate balance of many ecosystems. The effects on coral reefs, mountainous areas and the polar regions are already noticeable. The greater the biodiversity of a given ecosystem, the better able it is to adapt to change, and thus to mitigate the impacts of climate change for humankind. Animal and plant species given little regard today, or even as yet undiscovered, may well gain in significance as climate conditions change in the future.

In order for the rate of climate change to be slowed, greenhouse gas emissions – particularly carbon dioxide emissions – must be cut drastically and levels of greenhouse gases in the atmosphere reduced. Here, too, biological diversity is indispensable: intact species-rich ecosystems such as oceans, forests, wetlands and coral reefs can bind carbon dioxide. They play a key role in regulating the climate, at both regional and global levels.


Invasive species

Young Nile perch

More and more species are encroaching into habitats outside their original native habitats. This poses a further threat to biological diversity. To a certain extent, of course, this is a natural phenomenon, but the rates recorded in the past few decades have accelerated. This can be attributed to global travel and trade, in the course of which species are accidentally or deliberately introduced into new locations, and to climate change, which creates suitable conditions for the new arrivals.

The non-native species may displace native animal and plant species. This is the case when the invading species are particularly adaptable and encounter no natural predators in the new habitat. As a result, they therefore contribute to biodiversity loss, and are often the direct cause of economic damage.

Control and monitoring mechanisms must be established to prevent the expansion of potentially invasive species and also to combat the invasive populations that have already become established.


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