Sumatran rhinoceros

Numbers of the Sumatran Rhino have fallen 70 per cent in the last 20 years due to poaching, with fewer than 80 remaining   Picture: International Rhino Foundation CC BY 2.0  

The future global strategy for conserving biodiversity must include a prominent target to lower species extinction rates, similar to the 2-degree climate goal, say scientists.

An estimated one million species are now threatened with extinction globally and so far, action to deliver on the global agreements in place has failed to prevent significant biodiversity losses. Therefore, conservation experts – including Professor Paula Harrison of the UK Centre for Ecology & Hydrology (UKCEH) – are suggesting a clear goal to reduce extinctions to more natural rates.

Their new paper in the journal Science proposes the Convention on Biological Diversity (CBD) adopts a measurable target of fewer than 20 extinctions annually over the next 100 years, when it meets in 2021 to discuss new biodiversity goals and targets. This single, total extinctions target would apply to all described species across the major taxonomic groups (fungi, plants, invertebrates and vertebrates) and ecosystem types (freshwater, marine and terrestrial).

The paper’s authors are not suggesting that a single target is sufficient on its own to describe the changing state of biodiversity, or to guide conservation policy. Additional targets will be needed in the mix to ensure that biodiversity meets other functional and cul­tural roles that are especially important at local and national scales.

However, they believe such a clear goal is needed to galvanise both policy and public support for conserving biodiversity – similar to the way that the Paris Agreement target not to increase global temperatures above 2 degrees (compared to pre-industrial times) has prompted action on climate change. The authors propose basing this on the rate of species extinction as this represents the most fundamental aspect of biodiversity loss – an irreversible reduction in the diversity of life on Earth for which there is widespread public concern.

The climate change debate has shown that having a single indicator that’s widely understood can be a catalyst for inspiring public support and the demand for policy action - Professor Paula Harrison

Professor Harrison, Principal Natural Capital Scientist at UKCEH, says: “Raising public and political awareness of biodiversity loss is crucial to stimulating the concerted and coordinated action that will be needed to reverse it. The climate change debate has shown that having a single indicator that’s widely understood - such as species extinction - can be a catalyst for inspiring public support and the demand for policy action.”

“The COVID-19 pandemic reminds us of the critical balance between nature and people, and it has become vital to set out a clear agenda which offers solutions to biodiversity loss.”

In 2010, the CBD, the international treaty tasked with producing the global plan for biodiversity, set out a strategic plan for nature which included 20 time-bound, measurable targets to be met by the year 2020 (the Aichi Biodiversity Targets). Of these only four have shown good progress while 12, related to the state of nature, show significantly worsening trends.

The authors of the new paper in Science say much of the failure to make progress on existing biodiversity goals and targets can be attributed to a lack of mainstreaming of biodiversity in public policy, and limitations in raising the profile of species loss for politicians and the public.

Further information

The new paper in Science, entitled A biodiversity target based on species extinctions, is led by Professor Mark Rounsevell of the Karlsruhe Institute of Technology, Germany, and University of Edinburgh. In addition to Professor Harrison of UKCEH, co-authors are from the UN Environment World Conservation Monitoring Centre, University College London and the RSPB. DOI: 10.1126/science.aba6592

A report last year by world-leading scientists for IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) found that around 1 million animal and plant species are now threatened with extinction, many within decades, more than ever before in human history.

The IPBES Global Assessment built on four regional assessments published in 2018. Professor Paula Harrison was a coordinating lead author in the IPBES Regional Assessment for Europe and Central Asia and is currently a member of the IPBES Task Force on Scenarios and Models, which supports all the IPBES assessments.

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