Global biodiversity is collapsing, warn scientists

The first global assessment of biodiversity and ecosystem services has held humans largely responsible for looming mass extinction of species and has urged immediate action to avert disaster.

Hawksbill sea turtle
A hawksbill sea turtle. A new global biodiversity report shows that human action is accelerating the mass extinctions of species, all to mankind's own detriment. Image: Unsplash

Of the estimated eight million species on earth, around a million face extinction, according to biodiversity specialists from around the world. Many of these are now threatened with extinction within decades—a situation humans have not faced before.

The average abundance of native species in most major land-based habitats has fallen by at least 20 per cent, mostly since 1900. More than 40 per cent of amphibian species, almost 33 per cent of reef-forming corals and more than a third of all marine mammals are now threatened.

The picture is less clear for insect species, but available evidence supports a tentative estimate of 10 per cent being threatened. At least 680 vertebrate species had been driven to extinction since the 16th century and more than 9 per cent of all domesticated breeds of mammals used for food and agriculture had become extinct by 2016, with at least 1,000 more breeds still threatened.

We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide.

Sir Robert Watson, chair, Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) 

Accelerating extinctions

The rate of species extinction is accelerating, with grave impacts on people around the world, warns a report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). It is dedicated to providing the world with an objective, scientific view of climate change, its natural, political and economic impacts and risks, and possible response options.

While more food, energy and materials than ever before are now being supplied to people in most places, it is increasingly at the expense of nature’s ability to provide such contributions in the future and frequently undermines nature’s many other contributions, which range from water quality regulation to sense of place.

The biosphere, upon which humanity depends, is being altered to an unparalleled degree across all spatial scales. Biodiversity—the diversity within species, between species and of ecosystems—is declining faster than at any time in human history, says the report.

“The overwhelming evidence of the IPBES Global Assessment, from a wide range of different fields of knowledge, presents an ominous picture,” Robert Watson, IPBES chair, said at the launch of the report’s summary for policymakers. The summary was approved at a meeting of scientists and representatives of 130 governments, held in Paris from April 29 to May 4.

“The health of ecosystems on which we and all other species depend is deteriorating more rapidly than ever. We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide.”

Not too late

However, there was a word of encouragement. “The report also tells us that it is not too late to make a difference, but only if we start now at every level from local to global,” said Watson, who is associated with the Tyndall Centre at the Department of Environmental Sciences in the University of East Anglia, UK.

“Through ‘transformative change’, nature can still be conserved, restored and used sustainably… By transformative change, we mean a fundamental, system-wide reorganisation across technological, economic and social factors.”

This Global Assessment Report on Biodiversity and Ecosystem Services is the first intergovernmental report of its kind and builds on the landmark Millennium Ecosystem Assessment of 2005, introducing innovative ways of evaluating evidence.

Compiled by 145 experts from 50 countries over the past three years, with inputs from another 310 contributing authors, the report assesses changes over the past five decades, providing a comprehensive picture of the relationship between economic development pathways and their impacts on nature. It also offers a range of possible scenarios for the coming decades.

The full report—based on the systematic review of about 15,000 scientific and government sources—is still being compiled, and is scheduled for publication later this year.

Essential nature

The summary points out that nature is essential for human existence and good quality of life. Most of nature’s contributions to people are not fully replaceable, and some are irreplaceable. Nature plays a critical role in providing food and feed, energy, medicines and genetic resources and a variety of materials fundamental for people’s physical well being and for maintaining culture.

For example, more than two billion people rely on wood fuel to meet their primary energy needs, an estimated four billion people rely primarily on natural medicines for their health care and some 70 per cent of drugs used for cancer are natural or are synthetic products inspired by nature.

Over 75 per cent of global food crop types, including fruits and vegetables and some of the most important cash crops such as coffee, cocoa and almonds, rely on animal pollination.

Marine and terrestrial ecosystems are the sole sinks of the greenhouse gases now causing climate change. These ecosystems soak up around 60 per cent of the emissions.

The report draws on indigenous and local knowledge for the first time at a global scale. “Biodiversity and nature’s contributions to people are our common heritage and humanity’s most important life-supporting ‘safety net’. But our safety net is stretched almost to breaking point,” Sandra Díaz of Córdoba National University, and Investigador Superior in the Argentine National Research Council said at the launch. She has co-chaired the assessment with Josef Settele of the Helmholtz Centre for Environmental Research in Germany and Eduardo S. Brondízio of the Indiana University Bloomington, USA, the University of Campinas, and at the National Institute for Space Research, Brazil.

“Ecosystems, species, wild populations, local varieties and breeds of domesticated plants and animals are shrinking, deteriorating or vanishing. The essential, interconnected web of life on Earth is getting smaller and increasingly frayed,” Settele said in a statement. “This loss is a direct result of human activity and constitutes a direct threat to human well-being in all regions of the world.”

Five main culprits

Authors have ranked the five direct drivers of change in nature with the largest relative global impacts so far. In descending order of importance, they are changes in land and sea use; direct exploitation of organisms; climate change; pollution and invasive alien species.

The report says climate change is already impacting nature from the level of ecosystems to that of genetics, and these impacts are expected to increase over the coming decades, in some cases surpassing the impact of land and sea use change and other drivers.

The report bluntly says global goals for conserving and sustainably using natural resources and achieving sustainability cannot be met by the current business-as-usual approach. The scientists point out that loss of biodiversity is not only an environmental issue but also a developmental, economic, security, social and moral issue as well.

Three-quarters of the land-based environment and about 66 per cent of the marine environment have been significantly altered by human actions, though on average these trends have been less severe or avoided in areas held or managed by indigenous peoples and local communities.

This story was published with permission from The Third Pole. Read the full story.

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