Why biodiversity loss hurts humans as much as climate change

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02:28 mins.
06.05.2019

Extinction warning

A UN-backed report says a million species are at risk of extinction, and warns biodiversity loss and failure to conserve ecosystems has catastrophic effects on people as well as nature.

They are the tireless stewards of the air, water and land from which we live. But the millions of species whose toil underpins our prosperity are gravely endangered by human activity, scientists say — and that imperils us in turn.

Nature and Environment | 18.03.2019

Biodiversity loss is as big a threat to humans as climate change, said UN biodiversity chief Robert Watson last week at a conference in Paris to release a landmark report on global biodiversity and ecosystems.

"The continuing loss of biodiversity will undermine our ability for poverty reduction, food and water security, human health and the overall goal of leaving nobody behind."

The report, the first of its kind since 2005 and published today by the Intergovernmental Panel on Biodiversity and Ecosystem Services (IPBES), warns of grave consequences to humanity from mass die-offs and degradation of nature. Drawing together the work of more than 400 experts, it paints a bleak picture of a world in which essentials such as food and drinking water are endangered through species and ecosystem decline.

Nature and Environment | 25.02.2019

The unprecedented and accelerating deterioration of nature in the past 50 years has been driven by changes in land and sea use, exploitation of living beings, climate change, pollution and invasive species, the report found. These five drivers are, in turn, underpinned by societal behaviors ranging from consumption to governance.

In a blow to human progress, damage to ecosystems undermines 35 of 44 UN sustainable development targets for poverty, hunger, health, water, cities climate, oceans and land, the authors found.

Diplomats from 130 nations gathered in Paris last week to agree on the final wording of the report's summary for policymakers.

"The loss of species, ecosystems and genetic diversity is already a global and generational threat to human well-being," said Watson. "Protecting the invaluable contributions of nature to people will be the defining challenge of decades to come."

The Great Barrier Reef is an ecosystem dying from climate change

The Amazon rainforest's biodiversity is threatened by expanding cropland

Why biodiversity matters

Biodiversity, a contraction of biological diversity, means the abundance and variety of life on the planet. The definition encompasses more than just the creatures we can see. It ranges from tiny genes, bacteria, plants and animals, right up to ecosystems such as the Amazon rainforest and Great Barrier Reef.

That makes it hard to count — and even harder to value.

While there are about 1.5 million identified species in the world, scientists estimate the true figure may be closer to ten million or even as many as two billion. Many organisms are so small they can only be identified as distinct species through DNA sequencing.

"If you think about biodiversity, you think about tigers and polar bears," said Rebecca Shaw, chief scientist at the World Wildlife Fund. "Those species are very important — but also important are the species you never see and talk about."

Without bees pollinating crops and trees turning carbon dioxide into oxygen, even basic human tasks such as eating and breathing become harder. But quieter losses hurt people too, such as the decline of medicinal plants and mangroves that protect coastlines.

The ways in which organisms interact mean the decline of any single species can trigger unexpected losses in the wider ecosystem. For instance, a fall in earthworms, fungi or soil microbes limits the amount of recycled nutrients in the soil and the number of holes for rainwater to flow through, stunting crop growth and hindering humanity's ability to feed itself.

"We don't consider that nature, but it is nature," said Shaw. "Not paying attention to all those complex interactions in the soil — and thinking we can just put on fertilizer or pesticide and have it stay the same productive soil into the next generation — is foolish."

The report found that about a quarter of the plant and animal species assessed face extinction, many within decades, unless urgent action is taken.

How it hurts us

Counted by biomass, humans comprise just 0.01 % of global biodiversity.

But the report details the outsized ways in which our species has endangered others by razing forests, polluting rivers, overfishing oceans, killing off insects, and otherwise hurting nature in a headlong push to extract its resources.

"Nature makes human development possible but our relentless demand for the earth’s resources is accelerating extinction rates and devastating the world’s ecosystems," said Joyce Msuya, acting head of UN Environment.

Infografik Leben auf der Erde Biomasse EN

The report also found:

  • Human action has significantly altered more than two-thirds of the environment.
  • The global extinction rate today is tens to hundreds of times higher than its average over the past 10 million years.
  • More than a third of the world's land surface and nearly 75 % of its freshwater sources are now used for crop or livestock production.

Agriculture is particularly sensitive, with just nine plant species now accounting for more than two-thirds of global crop output, and, as Shaw described, the soil on which they grow under threat.

In a sign of the powerful feedback loops at play, agriculture is itself a major driver of biodiversity loss, with pesticides, soil erosion and forest clearance destroying habitats and sinking wildlife populations. And in addition to its effect on food systems, the devastation of the earth's soil reduces its ability to retain water, hitting humans by increasing water stress and the frequency of floods.

The repercussions of human activity on nature are made worse by climate change, the report found, which is in turn exacerbated by damage to ecosystems, such as loss of forests that convert carbon dioxide into oxygen.

A study published last year in the journal Science found that even if countries honor their current pledges to limit carbon emissions, 49 % of insects and 44 % of plants will lose more than half their geographical habitat by 2100.

Fungi and microbes work together to make soils fertile

How we can stop it

While some of the problems listed in the report have been known for decades, scientists have struggled to convey the urgency with which they need to be dealt.

In 2010, the United Nations declared a "decade of biodiversity" to reduce biodiversity loss. But according to today's report, it made good progress with only a handful of the 20 targets it set its members, such as conserving marine areas and prioritizing invasive alien species. Every target related to addressing the underlying drivers had seen either moderate or poor progress.

But, the report said, "urgent and concentrated efforts" can still conserve and restore nature so it can be used sustainably.

Conservation efforts have so far focused on big animals such as orangutans

Avoiding the negative effects of biodiversity loss to 2050 and beyond requires "transformative" policy change, the authors wrote. They proposed a broad-ranging toolkit of policies including sustainable agricultural practices, incentivizing reductions in consumption and waste, effective fishing quotas and collaborative water management.

While the report's recommendations were targeted at policy-makers, scientists say many consumer choices, such as reducing beef consumption and eating sustainably-sourced fish, are needed to conserve ecosystems.

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

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

Endangered natural world heritage

Belize Barrier Reef no longer endangered

Great news: UNESCO removed a portion of the Mesoamerican Barrier Reef System, the world's second largest coral reef, from the List of World Heritage in Danger. The outstanding natural ecosystem off the coast of Belize was put on the list in 2009. Since then, the government has stepped up conservation efforts, setting "an example for the rest of the world," said Mechtild Rossler of UNESCO.

Endangered natural world heritage

Dam threatens health of Lake Turkana

But there's also bad news: UNESCO newly listed Kenya's Lake Turkana National Parks as endangered due to concerns about a dam in neighboring Ethiopia, which is feared will disrupt the flow and ecosystem of Lake Turkana. The three national parks surrounding the lake are a stopping point for migratory birds, and a major breeding ground for crocodiles, hippopotamus and snakes.

Endangered natural world heritage

Dozens of endangered natural sites

There are more than 200 UNESCO Natural World Heritage sites around the globe; more than a dozen of them are endangered. The Manovo-Gounda St. Floris National Park in the Central African Republic, for example, was added to the "in danger" list in 1997 following reports of illegal poaching. According to some reports, hunters may have harvested as much as 80 percent of the park's wildlife.

Endangered natural world heritage

Deadly fight to protect Congo's wildlife

Preserving natural heritage sites can be a dangerous job. In the Virunga National Park, more than 175 rangers and guards have lost their lives since 1996 while protecting wildlife against poachers and other armed groups. The park in the Democratic Republic of the Congo hosts exceptional biodiversity and is home to the iconic mountain gorillas. It was added to the endangered list in 1994.

Endangered natural world heritage

The poaching problem

Global demand for ivory continues to be one of the main reasons why UNESCO considers natural reserves to be endangered. Tanzania's Selous Game Reserve, one of the largest remaining wilderness areas in Africa, was added to the list in 2014 because widespread poaching is decimating populations of elephants and rhinos.

Endangered natural world heritage

Endangered parks, endangered animals

Many of the endangered world heritage sites provide habitat for species that are threatened with extinction. Sumatran orangutans, for example, rely for their survival on three national parks collectively known as the Tropical Rainforest Heritage of Sumatra. However, illegal logging and extensive agriculture, including for palm oil, are destroying their habitat.

Endangered natural world heritage

Protecting livelihoods

Besides conserving biodiversity, UNESCO World Heritage also protects the livelihoods of local communities. More than 2,000 indigenous people have managed to preserve their traditional way of life in the Rio Platano Biosphere Reserve in Honduras. The reserve was removed from the endangered list in 2007, but added again in 2011 due to illegal logging. This is why locals are armed.

Endangered natural world heritage

Stepping up conservation

UNESCO's mission is to provide emergency assistance and to encourage local governments and citizens to participate in conservation efforts. Despite ongoing threats to many natural sanctuaries, the program has also yielded several success stories. The Galapagos Archipelago, for example, was removed from the endangered list in 2010 after Ecuador's government stepped up conservation measures.