Humans have introduced more than 37,000 invasive species, many harmful, into biomes around the world, threatening a range of plants and animals, finds a new study from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).
The Invasive Alien Species Report, produced by experts from 49 countries, says these intruders have been a major factor in 60 per cent of all extinctions and that they cost the global economy more than US$423 billion annually. The report called invasive alien species a threat to sustainable development and human wellbeing.
It comes with more than 1 million plants, animals and other living things facing the threat of extinction. The publication arrives as countries are working to speed up the implementation of the Kunming-Montreal Global Biodiversity Framework, a landmark agreement to halt and reverse nature loss by 2030.
Invasive alien species are one of the five major drivers of biodiversity loss and the framework aims to “eliminate (or) reduce” their impact on the environment.
Here’s a closer look at invasive alien species as well as the other top causes of nature loss identified by IPBES, an independent body that aims to help states sustainably manage biodiversity.
Invasive species
Invasive alien species (IAS) are animals, plants, fungi and microorganisms that have entered and established themselves in the environment outside their natural habitat. IAS have devastating impacts on native plant and animal life, causing the decline or even extinction of native species and negatively affecting ecosystems.
The global economy, with increased transport of goods and travel, has facilitated the introduction of alien species over long distances and beyond natural boundaries. The negative effects of these species on biodiversity can be intensified by climate change, habitat destruction and pollution.
IAS have contributed to nearly 40 per cent of all animal extinctions since the 17th century, where the cause is known. Meanwhile, environmental losses from introduced pests in Australia, Brazil, India, South Africa, United Kingdom and the United States are estimated to reach over US$100 billion per year.
IAS is a global issue that requires international cooperation and action. Preventing the international movement of these species and rapid detection at borders is less costly than control and eradication.
Changes in land and sea use
The biggest driver of biodiversity loss is how people use the land and sea. This includes the conversion of land covers such as forests, wetlands and other natural habitats for agricultural and urban uses.
Since 1990, around 420 million hectares of forest have been lost through conversion to other land uses. Agricultural expansion continues to be the main driver of deforestation, forest degradation and forest biodiversity loss.
The global food system is the primary driver of biodiversity loss, with agriculture alone being the identified threat of more than 85 per cent of the 28,000 species at risk of extinction.
Harvesting materials such as minerals from the ocean floor and the building of towns and cities also impact the natural environment and biodiversity.
Reconsidering the way people grow and consume food is one way of reducing the pressure on ecosystems. Degraded and disused farmland can be ideal for restoration, which can support protecting and restoring critical ecosystems such as forests, peatlands and wetlands.
Climate change
Since 1980, greenhouse gas emissions have doubled, raising average global temperatures by at least 0.7 degrees Celsius. Global warming is already affecting species and ecosystems around the world, particularly the most vulnerable ecosystems such as coral reefs, mountains and polar ecosystems. There are indications that climate change-induced temperature increases may threaten as many as one in six species at the global level.
Ecosystems such as forests, peatlands and wetlands.represent globally significant carbon stores. Their conservation, restoration and sustainability are critical to achieving the targets of the Paris Agreement. By working with nature, emissions can be reduced by up to11.7 gigatons of carbon dioxide equivalent per year by 2030, over 40 per cent of what is needed to limit global warming.
Pollution
