Loss of biodiversity

There are just under two million species mapped worldwide, and there are also many species that have not been described by science. It is estimated that the actual number of species on the planet is about eight to twelve million, most of which are insects. As of today, one million species are threatened with extinction. The loss of natural diversity is increasing and will have serious consequences for people around the world. More species are threatened with extinction now than at any other time in human history.

Photo: Unsplash.com

Loss of biodiversity in Norway

In Norway, approximately 44,000 species have been identified today. The total number is probably around 60,000. The Norwegian Red List of Species from 2015 shows that we have 2,355 threatened species in Norway. Of the species that are threatened in Norway, 87 percent are threatened due to various types of land changes. Deforestation, drainage, overgrowth, cultivation, demolition and damming are some examples of how we change species' habitats through our use of the land.

Examples from Europe

An example from Germany clearly shows the decline. Researchers took samples from 150 meadows and 140 forest areas for 10 years. In total, they counted about a million insects in three regions of Germany. One third of the sites examined were in protected areas. There were 78 percent fewer insects in the open areas during the period. On average, species diversity was reduced by a third. Many insects were also in sharp decline in the forest. The weight of the catch decreased by 67 percent in meadow areas and 41 percent in the forest over the ten years.

There was not much difference based on how the forest and pastures were used. So, there were about the same number of insects that disappeared from nature reserves as other areas. What was more important was how the surrounding landscape looked. Especially in open areas. The researchers found that there were fewer species the more cultivated land there was around the meadows. The decline in insect numbers did not seem to have stopped when the study ended.

Photo: Kore Foundation.

IPBES – The International Panel on Environmental Issues

The International Panel on Biodiversity, IPBES, was established in 2012 and is an independent intergovernmental scientific body that compiles and presents global scientific expertise on the environment. The Panel is administered by the United Nations Environment Programme.

In 2019, the Intergovernmental Science-Policy Platform on Biodiversity (IPBES) released its report on the state of the world's biodiversity. It states that the rate of extinction is now ten to a hundred times faster than it has been over the past 10 million years, and it is accelerating. As of today, one million species are threatened with extinction.

The decline in the number of wild mammals is described as dramatic. Humans and domestic animals now account for a full 95 percent of mammalian biomass, i.e. our total weight.

Causes of species loss

The direct causes of species loss, ranked by importance, are, according to the report: Shrinking habitat, hunting and fishing, illegal trade in animal parts, climate change, pollution and alien species. Human activity has caused extensive changes in 75 percent of the terrestrial environment, 50 percent of the rivers and 66 percent of the marine environment. 75 percent of land areas have been significantly altered, 66 percent of the oceans are increasingly affected, and 85 percent of the world's wetlands have been lost.

Sources and resources

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