In this blog, Professor Richard Gregory (Head of Monitoring, Conservation Science) describes a new paper, on which he is a co-author, that proposes a single target for the recovery of nature to inform a quickening debate on global biodiversity goals. This is set in the context of the RSPB’s hopes for the post-2020 Global Biodiversity Framework.

Defining a target

Despite all good intentions, biodiversity is on a downward slide.  Headlines each week remind us of growing threats to nature, often focussing on the rarest enigmatic species, and warn of mass extinction, population declines and an overall accelerating crisis. International commitments to reduce the rate of biodiversity loss at the global, regional and national levels, have come and gone with little apparent effect. Of the 20 Aichi Biodiversity Targets established in 2010 by the Convention on Biodiversity (CBD), only four show good progress, whereas twelve related to the state of nature show worsening trends. The overall state of nature gets worse rather than better. 

Part of that collective failure is about a lack of mainstreaming since biodiversity just doesn’t have the cut-through and profile that other sectors have in society, like economics or health. A further failing is that the targets have not been very ‘SMART’ and that ambiguity has added confusion and has muddied the waters. Some have argued that an important failing has also been a lack of consensus on a single target for nature - a ‘North Star’ for the recovery of biodiversity. There are many proposals for what this could be. Some have called for bold targets to protect half the earth, others to protect intact wilderness, but most of these describe actions and means to protect biodiversity, and not biodiversity itself.

A new paper published in Science today by Rounsevell et al. adds to these suggestions, proposing a single outcome-oriented target for biodiversity. Specifically, it proposes a target of keeping described species extinctions to below 20 per year over the next 100 years across all major groups (fungi, plants, invertebrates, and vertebrates) and across all ecosystem types (marine, freshwater, and terrestrial). Thereafter, with the stabilization of human impacts, it suggests a rate closer to the background extinction rate

The iconic Passenger pigeon was described as occurring in North America in "infinite multitudes", no one would have imagined its demise, but excessive hunting pressure and habitat change drove it rapidly to extinction around 1900. The last known bird, called Martha, died in captivity in 1914

Extinction is a fundamental part of biodiversity loss, representing the irreversible loss of a species and unique genetic material - a measurable reduction in the diversity of life on Earth. This is a simple, easily understood extinction target that will resonate with different audiences and is designed to catalyse significant action to bring about change and improve the state of biodiversity. The figure 20 extinctions per year over the next 100 years is based on a target to reduce extinctions to 10 per million-species-years, as applied to the estimated 2 million described species. The 10 per million-species-years rate is also the threshold adopted by the Planetary Boundaries framework.

Crucially, Rounsevell et al. do not suggest that this single metric is enough on its own to describe the changing state of biodiversity or to guide conservation policy. Additional targets and metrics will be needed to ensure that biodiversity meets other functional and cultural roles that are especially important at local and national scales - and they will need to include for example species abundance and habitat integrity. Extinction itself can also be difficult to pin down in real-time, so surrogate indicators, such as the number of Critically Endangered species in a group, might be used to define milestones and measure progress.

Indeed, as part of a framework of targets, ambition on reducing extinction should sit alongside equivalent measurable and ambitious outcomes for species populations, and habitat quality and extent.

From policy to action

Target setting is the first step in the theory of change that is described. For targets to be successful, translatable at the national level, and to foster accountability, they have to be “SMART”. The proposal by Rounsevell et al. is a big step towards improving how we consider species extinctions as a global target.

When translating this into national commitments we need to consider that some countries are home to a disproportionately high number of endangered species, and some countries have a disproportionate impact on endangered species in other countries through their consumption patterns, so such inequalities would need to be recognised and addressed in any response.

We know that the most important drivers of biodiversity losses globally are land- and sea-use change, direct exploitation of organisms, climate change, pollution and invasive alien species; and we need to set ambitious commitments to tackle these as well. New national commitments under the CBD post-2020 biodiversity framework would need to include concerted action to protect threatened species in species action plans, to guard key areas for biodiversity as protected areas, to restore degraded habitats, to promote sustainable land use policies, to control illegal wildlife trade, to raise environmental standards for e.g. in pollution control, biosecurity, and to phase out subsidies that incentivise damage. Governments would need to monitor and report on the effectiveness of their actions in a robust and transparent fashion at regular intervals within the 10-year framework, building on the existing reporting mechanisms.

Looking forwards

Discussions to inform the post-2020 global biodiversity framework are advancing apace. The 15th meeting of the Conference of the Parties to the CBD will take place in China in 2021 and a new set of global targets for biodiversity will be ratified. The importance of a strong target, or set of targets, for the recovery of species and ecosystems cannot be underestimated as they are likely, with other driving factors, to determine the fate of nature.

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