The Science Supporting a 30% Conservation Target

Whether industry likes it or not, ambitious resource protection goals are here to stay

At the UN Biodiversity Conference held this past December in Montreal, nearly 200 countries[i] agreed to adopt the Global Biodiversity Framework (GBF). Among the 26 targets set out in the draft document is the much-publicised “30 by 30” commitment: to protect 30% of Earth’s land and marine surfaces by the year 2030. Since UN figures indicate that only 17% of land and inland water ecosystems and only 8% of coastal ecosystems and ocean are currently protected, 30% represents a significant increase.

How did the UN arrive at this figure?  The Framework document does not say. My curiosity piqued, I looked to the internet for answers.

Useful Starting Points

Not surprisingly, there appears to be a strong environmental lobby behind the 30% target, with many such lobbyists citing scientific sources to back their claims. In particular, I found websites by these two groups to be particularly useful:

• The Campaign for Nature, a partnership of the US-based Wyss Foundation and the National Geographic Society, and

• The High Ambition Coalition for Nature and People, an intergovernmental organization.

Both sites offer links to and summaries of government reports, scientific papers, and other information to support their cause. Roughly half of these publications offer justification for a specific numeric target.

Estimates Vary as to How Much Protection Is Needed 

Most of the papers listed on the two groups’ websites call for the protection of between 30% to 50% of the Earth’s surface. However, three literature review papers (papers that summarize previous scientific studies) show a wide range of different scientific opinions. They also highlight the challenges of comparing studies with different methods, assumptions, and definitions.

For example, the paper Effective Coverage Targets for Ocean Protection examines 144 studies, and finds that, on average, the papers recommend 37% of the oceans be protected. However, the numbers vary greatly, from about 10% to about 90%. Further, the median and modal values, at 32% and 21-30% respectively, are significantly lower than the average. Part of the complexity is due the fact that the different papers reviewed had different objectives. For example, some calculated the area needed to protect fisheries value, whereas others targeted biodiversity.

Bolder Thinking for Conservation proposes a 50% protection target, based on a comparison of suggested targets from 16 scientific papers and reports. This paper’s 50% target, described as being “slightly above the mid-point of recent evidence-based estimates,” is justified as being precautionary (Figure 1).

Figure 1 from "Bolder Thinking for Conservation" (Noss et al., 2012). Triangles represent existing biodiversity targets, whereas squares represent targets suggested by scientific works. Vertical lines are ranges of values within published studies and points are reported means or medians of range. The original study provides detailed descriptions of the different data points.

Without seeing the actual calculations, I would hesitate to comment on the authors’ conclusion that 50% is indeed an appropriate target. However, the paper presents a good window into conservation scientists’ thought processes.

A Primer on Conservation Methodologies

Reading The Minimum Land Area Requiring Conservation Attention to Safeguard Biodiversity gave me a better understanding of how conservation scientists arrive at their estimates. This paper highlights three commonly used methodologies:

• Efficiency-based planning approaches, which design conservation areas to maximize the number of species and ecosystems represented,

• Site-based approaches, which identify areas that are significant to biodiversity preservation (such as the International Union for the Conservation of Nature (IUCN)’s Key Biodiversity Areas (KBAs) standard), and

• Approaches that identify and protect untouched wilderness areas.

The paper points out that the three different methodologies have different strengths and weaknesses, and often lead to different results. The solution is to combine methodologies. Starting with current protected areas, it then adds the area of the world’s currently unexploited wilderness (such as much of Canada’s boreal forests), and finally adds additional areas to maximize species and ecosystems. By doing so, it arrives at a conservation target of 44%[ii].

A similar layering methodology is used in the paper A “Global Safety Net” To Reverse Biodiversity Loss and Stabilize Earth’s Climate. By starting with current protected areas and then adding areas for “intactness” (i.e., current wilderness, such as much of Canada), rare species, distinct ecosystems, rare phenomena, climate stabilization, and wildlife corridors, the paper concludes that the conservation of 50% of the earth’s surface is needed to protect biodiversity and carbon sequestration.

Scientists as Lobbyists 

Some of my peers have questioned whether the 30% conservation target set out in the Global Biodiversity Framework (GBF) is indeed purely scientific, or whether it is instead the result of lobbying efforts by environmentalists. After examining the scientific literature on the topic, I would argue that the question is moot: conservation biology and activism are one in the same thing.

After reading through the papers listed on the Campaign for Nature and High Ambition Coalition websites, I actually find myself relieved that the GBF limited its demands to 30% rather than calling for even more protection. This may be what the papers’ authors strived to achieve with their writing. While I am not convinced that we need to preserve half of Earth’s surface area, my frame of reference has indeed been shifted.

The paper Bolder Thinking for Conservation provides an example of conservation biologists’ approach to advocacy. It concludes with a call to action: “Nature needs at least 50%, and it is time we said so.” Rather than examining ambitious conservation strategies through a “political filter” (because “most [of such strategies] would fail to pass in the current political climate”), conservation scientists are encouraged to help change the political reality. To this end, the paper asserts that scientists must be involved in “explaining and marketing biodiversity conservation in compelling ways” so that citizens are more likely to “think about conservation when they vote make purchases, or decide about uses of land and natural resources.” Such statements should give resource managers pause for thought.

The Demands for 30% Are Not Going Away

As scary as a 30% protected area target may be to the forest industry (and as critical some of us may be of the science underpinning it), we can’t ignore the issue. The papers I discussed in this essay don’t represent fringe beliefs; indeed, they have been published in mainstream journals, including Science and Nature.  Moreover, the conservation biology community has been actively, and successfully, working to turn its ideals into political reality.

What we can do is engage – with conservation biologists, policy makers, and all of the many other stakeholders in global forest management. If we don’t, we may find that many land use decisions are made without us.

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[i] Most large counties, including Canada, are included among signatories. The US, however, is notably absent, largely due to resistance from Republican senators. Instead, the country has launched its own “30 by 30” program.

[ii] Overlapping areas (i.e. areas that fall into more than one category) are subtracted.