Fear and Hope: One Million Species at Risk of Extinction
An Envirobites post in March 2019 described a “call to restore insect diversity.” (Baumann 2019). Now, a United Nations report (UN 2019), which received extensive media coverage, broadcasts that alarm even louder and more broadly with a call to restore the diversity of all species (Díaz 2019).
Worldwide Status of Biodiversity
First, this is a major, evidence-based report, meant to shock and motivate. The new publication, from the UN Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (UN IPBES), was developed over three years by 145 scientific experts from 50 countries with an expected final length of more than 1500 pages. The report is based on about 15,000 sources, which notably include not just mainstream science but also indigenous and local knowledge. This is the first major international assessment of biodiversity since 2005, approved by 132 countries (Tollefson 2019). In other words, this is a big deal.
Here’s the fear part. The report found that many groups of species are threatened: for example, more than 40% of amphibians, nearly 1/3 of reef corals, and at least 1/3 of marine mammals. Already humans have driven at least 680 vertebrate species to extinction since the 16thcentury, and, since about 1900, the abundance of terrestrial native species has declined by an estimated 20%.
“…around 1 million animal and plant species are now threatened with extinction, many within decades, more than ever before in human history.” (Díaz 2019). See Figure 1 for details on the methods used to develop this estimate.
Pressures driving extinction
What are the main culprits of this unprecedented threat to biodiversity? The authors ranked the pressures in the following descending order: (1) changes in the use of land and oceans, (2) direct exploitation of organisms, (3) climate change, (4) pollution, and (5) invasive non-native species. A major factor in both terrestrial land use and climate change, agriculture has an outsized impact on ecosystem services and biodiversity.
A few numbers from the report jump out in support of these conclusions. Three-quarters of terrestrial lands and 2/3 of oceans have been seriously altered by humans. These impacts are lower, however, on lands managed by indigenous and local peoples. Crops and livestock use more than 1/3 of the Earth’s land surface (Figure 2). One-third of fish stocks are being unsustainably harvested. Since 1980, the use of resources has doubled, the production of plastic pollution increased tenfold (Figure 3), and greenhouse gas emissions has risen two-fold, which has increased average global temperature by at least 0.7 oC. Finally, where it has been assessed, the number of non-native invasive species has risen by 70% since 1970.
The future: Daunting but hopeful
The report is not all doom and gloom. There’s hope. The report cites initiatives that are raising consciousness, protecting land, restoring ecosystems, and promoting sustainable economies. The authors specifically describe the recent awakening of young people. In an opinion piece for the The New York Times, David Greaber reports on thousands of activists in the recently-formed “Extinction Rebellion” protesting threats to biodiversity (Graeber 2019).
The challenge is daunting, however. The report explores a wide range of possible future policy scenarios. All of these lead to continuing threats to biodiversity in this century, except for those involving “transformative change.” These include critical alterations of agriculture, forestry, use of marine resources, energy production, and finance—to name a few. Especially prominent in policies that would sustain biodiversity is the development of a global economy that departs from contemporary paradigms of economic growth.
The report includes many examples of solutions to the biodiversity crisis. To address land use issues, the authors recommend the pursuit of landscape planning that targets food security, the livelihood of local people, biodiversity, and ecological services. A complementary approach targeting clean water, one of those ecological services, would be effective integration of water conservation and governance from local to regional scales, with meaningful involvement by local people. The report discusses the importance of enhanced conservation of genetic resources of wild and domesticated species as a strategy for restoring biodiversity. To abate the overexploitation of marine resources, the publication points to effective fishing quotas, marine protected areas, and ecosystem management. Finally, the authors emphasize the importance of nature-based solutions and healthy environments for low-income communities. Recommendations in the report go beyond most calls-to-action by emphasizing the importance of diverse value systems and interests, including the meaningful participation of indigenous and local communities.
An independent analysis of the UN biodiversity panel’s work, commissioned by IPBES, was published in April 2019 (UN IPBES 2019). That report, led by Peter Bridgewater, an ecologist at University of Canberra, concluded that the scientific basis of the biodiversity report was impressive, but recommended the development of partnerships with governments and communities and more specific and practical policies at local and national levels.
According to IPBES Chair, Sir Robert Watson. “…it is not too late to make a difference, but only if we start now at every level from local to global.” (UN IPBES 2019).
References
Purvis, A. 2019. How did IPBES estimate “1 million species threatened with extinction?” in Global Assessment Report. IPBES: https://www.ipbes.net/news/how-did-ipbes-estimate-1-million-species-risk-extinction-globalassessment-report. [Accessed, May 23, 2019]
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