How does global climate change affect biodiversity?

The massive loss of biodiversity is as threatening for humans as climate change

They are the tireless stewards of the air, water and the land on which we live. But the millions of species, the diversity of which is our prosperity, are seriously endangered by human influence, say scientists - and that in turn endangers us.

Biodiversity loss is just as great a threat to humans "as climate change," said Robert Watson, head of the United Nations for biodiversity, at a conference in Paris last week. Scientists there have now presented a groundbreaking report on global biodiversity and the state of our ecosystems.

"The ongoing loss of biodiversity will undermine our ability to fight poverty, maintain food and water security, protect human health and achieve the ultimate goal of leaving no one behind."

The report, the first of its kind since 2005, was published today by the Intergovernmental Panel on Biodiversity and Ecosystem Services (IPBES). He warns of serious consequences for mankind from massive species extinction and destruction of nature. The report summarizes the work of more than 400 experts and paints the grim picture of a world in which vital goods such as food and drinking water are threatened by the decline of species and the degradation of ecosystems.

The unprecedented and accelerated erosion of nature over the past 50 years has been caused by changes in land and marine use, animal exploitation, climate change, pollution and invasive species, the report said. These five factors in turn are promoted by social behavior that ranges from consumption to political control.

The destruction of ecosystems also threatens human progress and has undermined 35 of the United Nations 44 goals for sustainable development, including those for poverty, hunger and health, according to the authors.

The Great Barrier Reef ecosystem is dying from climate change.

Diplomats from 130 nations met in Paris to agree on the final text of the report summary for policy makers.

"The loss of species, ecosystems and genetic diversity is already a global and intergenerational threat to human well-being," said Watson. "Protecting nature's inestimable contributions to human beings will be the crucial challenge for the next few decades."

Why biodiversity is important

The word biodiversity stands for biological diversity and describes the abundance and diversity of life on the planet. The definition encompasses more than just the animals and plants we can see. It ranges from tiny genes, bacteria, plants and animals to ecosystems like the Amazon rainforest and the Australian Great Barrier Reef.

That makes it difficult to quantify biodiversity - and even more difficult to evaluate.

While there are around 1.5 million species identified worldwide, scientists estimate that the actual number could be closer to ten million or even as high as two billion. Many organisms are so small that they can only be identified as distinct species by DNA sequencing.

"When you think of biodiversity, you think of tigers and polar bears," said Rebecca Shaw, senior scientist, World Wildlife Fund. "These species are very important - but also the species you never see and talk about."

Without bees pollinating plants and trees, which convert carbon dioxide into oxygen, even basic human tasks like eating and breathing become more difficult. But less obvious losses also harm people, such as the decline in medicinal plants and mangroves that protect the coasts.

The biodiversity in the Amazon rainforest is threatened by expanding arable land.

Because organisms interact in many ways, the disappearance of a single species can cause unexpected losses throughout the ecosystem. For example, a decline in earthworms, fungi or soil microbes limits the amount of recycled nutrients in the soil and the number of holes through which rainwater flows, which in turn hinders plant growth and thus the ability of humans to be self-sufficient.

"We don't see that as nature, but that is nature," Shaw said. "Not paying attention to all of these complex interactions in the soil - and thinking that we can just apply fertilizer or pesticides and keep the same productive soil for the next generation - is foolish."

The report found that around a quarter of the plant and animal species studied are critically endangered, many of them within the next few decades, unless action is taken very quickly.

Why it harms people

If you only calculate the biomass, humans only make up 0.01 percent of global biodiversity.

But the report describes the oversized proportions to which our species endangers other species. Forests have been destroyed, rivers polluted, oceans overfished, insects killed, and nature otherwise harmed and exploited to extract resources.

"Nature enables human development, but our relentless demand for the earth's resources is accelerating the rate of extinction and destroying the world's ecosystems," said Joyce Msuya, assistant director of the United Nations Environment Program.

The report also notes:

- More than two thirds of the environment has changed significantly through human activity.

- The global extinction rate today is three to ten times as high as the average for the last 10 million years.

- More than a third of the world's land area and almost 75 percent of freshwater sources are used today for plant or animal production.

Agriculture is particularly sensitive, as only nine plant species now make up more than two thirds of the world's harvest and the soil on which they grow is threatened by erosion, urbanization and deforestation.

As a sign of the strong feedback loops, agriculture itself is an important driver of the loss of biological diversity: pesticides, soil erosion and deforestation destroy habitats and decimate wildlife. And the devastation of soils not only reduces their usefulness in producing food, but also their ability to store water, which also leads to more water scarcity and more frequent floods for humans.

The effects of human activity on nature are compounded by climate change, which in turn is compounded by damage to ecosystems, such as the loss of forests that convert carbon dioxide into oxygen, the report said.

A study published in Science last year found that even if countries meet their current commitments to limit carbon emissions, 49 percent of insects and 44 percent of plants will lose over half of their habitats on earth by 2100.

Fungi and microbes work together to make the soil fertile.

How can we stop it?

While some of the issues listed in the report have been known for decades, scientists struggle to convey the urgency with which they need to be addressed.

In 2010 the United Nations proclaimed a "Decade of Biodiversity" to reduce the loss of biodiversity. But according to today's report, it has only made good progress on a handful of the 20 goals it has set for its members, including marine conservation and prioritization of invasive alien species. Any goal related to the underlying drivers behind this development had made only moderate or poor progress.

But, according to the report, "urgent and concentrated efforts" can still preserve and restore nature so that it can be used sustainably.

The efforts of many conservationists have so far focused on large animals such as orangutans.

In order to avoid the negative effects of the loss of biodiversity by 2050 and beyond, a "transformative" policy change is necessary, the authors write. They propose a wide range of measures that include sustainable farming practices, incentives to reduce consumption and waste, effective fishing quotas and collaborative water management.

While the report's recommendations are aimed at policy makers, scientists say that many consumer choices, such as reducing beef consumption and consuming fish from sustainable sources, are necessary to preserve ecosystems.

The authors also stressed the importance of developing global financial systems away from the "limited paradigm" of economic growth.

"The report also tells us that it is not too late to make a difference, but only if we start now at all levels from local to global," said Watson.

  • Endangered world natural heritage sites

    Belize Barrier Reef out of danger

    Good news: UNESCO has removed the Belize Barrier Reef in the Caribbean from the list of endangered world natural heritage sites. The world's second largest coral reef was classified as endangered in 2009 due to mangrove deforestation and planned oil drilling. Since then, Belize has passed laws to protect the reef and is considered a "positive example for the rest of the world," according to the committee.

  • Endangered World Heritage Sites

    Dam threatens Lake Turkana

    However, there is also bad news: Kenya's Turkana Lake and its surrounding national parks were put on the Red List this year. A planned hydropower plant in the neighboring country of Ethiopia could dry up Lake Turkana even further and thus permanently impair the habitat for people and animals. The lake is a breeding ground for crocodiles, hippos and snakes.

  • Endangered World Heritage Sites

    A dozen national parks are at risk

    In total there are over 200 world natural heritage sites; more than a dozen of them are considered endangered. The Manovo-Gounda St. Floris National Park in the Central African Republic was added to the Red List in 1997 because poachers illegally hunt animals. According to UNESCO, poachers could have wiped out up to 80 percent of the wildlife in the park.

  • Endangered world natural heritage sites

    Deadly battle for Congo's natural treasure

    In some parts of the world, protecting national parks is life-threatening. In Virunga National Park, more than 175 rangers and security guards were killed by poachers and other armed groups. The reserve in the Democratic Republic of the Congo is best known for the mountain gorillas that occur here. It was classified as endangered in 1994.

  • Endangered World Heritage Sites

    The hunt for ivory

    The continuing demand for ivory is one of the main reasons why UNESCO puts natural heritage sites on the Red List. The Selous Game Reserve in Tanzania has been endangered since 2014 because poachers decimated elephant and rhinoceros populations. UNESCO has called on the world community to support Tanzania in the fight against ivory smuggling.

  • Endangered World Heritage Sites

    Home for endangered animals

    Many of the endangered world natural heritage sites provide the last remaining shelter for animal species threatened with extinction. The Sumatran orangutans depend on the UNESCO World Heritage Site of the Tropical Rainforests of Sumatra. Nevertheless, growing agriculture and illegal clearing rob them of their habitats.

  • Endangered World Heritage Sites

    Protection of indigenous people

    Not only animals depend on the World Heritage Sites for their habitat, but also some indigenous peoples. In the Rio Platano biosphere reserve in Honduras, around 2000 indigenous people were able to preserve their traditional way of life. The reserve was put on the Red List in 2011 due to illegal logging and conflict. That's why locals are armed like in this photo.

  • Endangered world natural heritage sites

    More nature protection

    The task of UNESCO is to encourage governments to do more nature conservation. Although many national parks are still considered endangered, the United Nations organization has also achieved some successes: The Galapagos Islands, for example, were removed from the Red List in 2010 after Ecuador regulated tourism and housing more closely.

    Author: Katharina Wecker