Without action, the world faces mass extinction

Currently, one million plant and animal species are threatened with extinction in the coming decades. Ahead of the UN summit on biodiversity, there is no lack of tools to preserve a functioning ecosystem – but as it looks now, the world is going in the wrong direction.

The loss of species is one of many pressing issues that the COP15 summit, which begins Wednesday in Montreal, is supposed to address. The sixth mass extinction, as it has also come to be called, is about the fact that extinction today is going significantly faster than the natural rate.

– Biodiversity is dynamic, new species appear and species disappear, but it happens relatively slowly, says Henrik Smith, professor of zooecology at Lund University:

– What has been shown is that species become extinct at a rate that is much, much higher. It will not be able to be compensated by new species formation, which means that we will have fewer species on earth in the future. It takes an extremely long time for evolutionary processes to compensate for this, he says.

Wild vertebrates are rapidly declining

If development continues at the same rate as it is today, a million plants and animals are threatened with extinction in the coming decades. The conclusion was drawn by IPBES, biodiversity’s counterpart to the UN’s climate panel IPCC, in 2019 in a comprehensive report that took over three years to compile with the help of over 400 experts.

Since then, the mapping of the world’s species has continued and the warnings have increased. In the World Wide Fund for Nature’s (WWF) latest report “Living Planet 2022”, it is stated that the populations of wild vertebrates – mammals, fish, birds, amphibians and reptiles – decreased by an average of 69 percent from 1970 to 2018.

The last time a mass extinction took place was 65 million years ago. By all accounts, then, an asteroid impact and its consequences were behind the disappearance of 75 percent of all life on the planet, including all the dinosaurs.

Today, threats come from several directions at the same time. But the biggest damage, both in more recent history and up to today, is man’s overuse of the earth’s resources, says Henrik Smith.

– Deforestation is a central cause of the loss of biological diversity, he says.

Specialists have it the hardest

Deforestation is greatest in warm and tropical areas with very untouched nature. In addition to a high density of biological diversity, there are also more unusual species that often require a specific environment and food to survive, so-called specialists. As their habitat shrinks, the unique but important species are slowly but surely disappearing.

In a future and more gloomy existence, they have to bow down to more adaptable animals such as the rat, the raccoon and the cockroach. What the chain effects will be from a scenario without diversity is difficult to overview.

– Diversity plays a major role in many ecosystem functions. We need pollinators, biological control of pests and sequestration of carbon to manage the climate, says Henrik Smith.

Interaction with plants

It is the pollinators, such as bees and butterflies, that play a decisive role for many plant species. If the animal that helps to fertilize a tree or flower, for example by spreading its seeds, dies out, the plants risk doing the same, says Aelys Humphreys, Associate Professor at the Department of Ecology, Environment and Botany at Stockholm University.

– And it goes both ways. If more and more plants die out, the animals that depend on the plants for food, or for a place to nest or to lay eggs on them, are affected, she says.

Like many animal species, deforestation and agriculture are also the greatest threat to biodiversity among the earth’s plants. Today, it is known that around 600 plant species have died out in the last 250 years, but most suggest that this is an underestimate.

– There are very species-rich areas, such as in parts of tropical rainforests in South America or in Africa, which are not so well studied. There are probably more plants that have died out that we haven’t discovered yet, says Aelys Humphreys.

Nature surprises

The situation may sound both bleak and hopeless, but in many areas the development has proven to be reversible.

A proven way is through protected areas, both on land and out to sea.

Previously, it was known that fishing-free zones benefited the marine environment for crustaceans, corals and other living organisms in the area they protected. But new studies show that the marine nature reserves have more fortunate side effects than one might have thought at first.

A strong protection not only helps to improve the absorption of carbon dioxide and thus limit the emissions of greenhouse gases – it also contributes to a richer marine environment outside the protected area.

An example is the large nature reserve Papahānaumokuākea outside Hawaii, which was established in 2006.

There, researchers have shown that the protection also helped the stock of tuna and other migratory fish to increase sharply. Outside the nature reserve, the catch of yellowfin tuna has increased by over 50 percent.

Tighter controlled fishing is also believed to be the reason why the bluefin tuna began to reappear in Swedish waters a few years ago, after being absent for almost 60 years.

But in order for protected areas not to become just a limited success story, a comprehensive green infrastructure is required, says Henrik Smith.

– Protected areas are important, but living organisms do not only stay within them. Therefore, we must also take biodiversity into account in the rest of the landscape so that species have the opportunity to spread between the areas, he says.

Between 2010 and 2020, protected natural areas in the world increased from 10 to 15 percent on land, and from 3 to 7 percent at sea. However, it did not reach the so-called Aichi targets, which were established within the UN Convention on Biological Diversity (CBD), whose goal was to protect 17 percent of land and 10 percent of sea.

For COP15, a goal has been put forward that 30 percent of important habitats on land and at sea should be protected by 2030. The proposal is expected to be debated, and whether it will be hammered through remains to be seen.

– The situation is not hopeless in the sense that we cannot preserve biological diversity. There is no shortage of tools, but an insight and some sacrifices are required – because we will get something very valuable out of it, says Henrik Smith.

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