“We have to approach biodiversity conservation holistically”

A sense of alarm – that was the dominant reaction in May when the World Biodiversity Council announced its findings on the state of biodiversity and our ecosystems. Yet various scientists have already proposed ways of tackling species conservation. The most ambitious plan calls for placing half the planet under protection. Researchers from CDE and the University of Cambridge have taken a first-ever empirical look at the consequences of such a policy – who could be affected and what it might mean.

Julie Zähringer. Photo: Gaby Allheilig

Interview: Gaby Allheilig

Julie Zähringer, you and Judith Schleicher, of the University of Cambridge, have revealed what areas and how many people could be directly affected by the “Half Earth” proposal. What are your most important findings?

It’s the number of people that the strategy could impact by 2050: Over a billion people live in places that would be declared conservation areas. Today, there are already 250 million people living in such areas – 760 million more would be added based on newly created conservation zones. Some of these protected areas would occur in places where humankind’s footprint is biggest, such as the US west coast or the greater London area. This raises questions of feasibility and of social impacts in particular.


“The conservation strategy would mainly affect people in poorer countries”


But your study suggests that most of the people affected would be in poorer countries.

Exactly. We looked at the areas where people would be affected and compared them with the World Bank’s country classifications – high, upper-middle, lower-middle, or low income. We found that the majority live in lower-middle- and low-income countries. So, this conservation strategy would have a relatively modest impact on people in wealthy countries. It would mainly affect people in developing and emerging countries.

The initiators of the “Half Earth” proposal have yet to say exactly where the conservation zones would be located. Based on what assumptions did you make your calculations?

We based our calculations on 846 so-called ecoregions distributed all over the world. It is assumed this would enable protection of the highest-possible level of ecosystem and species diversity. When selecting specific areas in each ecoregion, we assumed that areas with the smallest human footprint would be prioritized for protection.


“Information is still lacking on the type of conservation”


On this basis, we carried out our calculations twice: The first time, we simply assumed that 50% of the land area of all ecoregions would be protected; the second time, we excluded all the strongly degraded ecoregions where there’s not much left to protect. Our first calculation led us to the estimated one billion people affected, as already mentioned. The second calculation left us with 170 million – roughly the population of the UK, Thailand, and Morocco combined.

Aren’t your assumptions a bit exaggerated?

No, on the contrary, they’re very conservative. Realistically, additional criteria would have to be incorporated. For instance, protected areas would likely need to be a certain size, and multiple areas would have to be connected by nature corridors. This would automatically affect more people.

What would be the consequences of protected areas for affected populations?

That depends entirely on the type of protection the areas are placed under. We couldn’t say anything about this in our study, since the proponents of the “Half Earth” proposal haven’t provided any information about the model or models they would like to see implemented.

Some regions already have lots of protected areas. What would happen with them?

In ecoregions where almost half of the area or more is already protected, this proposal probably wouldn’t add much. The Amazon Basin is one example.


“Unprotected areas impact conservation zones”


The Amazon shows that conservation often doesn’t work. In Brazil, illegal logging is happening more than ever.

Conservation implementation is another story. A global analysis was recently published examining different factors that influence the effectiveness of biodiversity protection. The study found that financial resources, staff, and material resources are the key factors for successful species protection.

With global warming, ecosystems and species will gradually shift to other areas. Are static conservation areas even workable?

In the past, the assumption was always that we would place areas under protection that harbour species worth conserving. But climate change presents planners with new challenges. Between now and 2050, certain endangered species will move to higher and cooler regions. What’s more, the 50% protected areas won’t be completely shielded from outside influences. Instead, whatever happens in the unprotected areas will impact the conservation zones – for instance, when pesticides get into river systems. So, it’s important to think more about process-oriented measures that will contribute effectively to biodiversity conservation, and then adapt these measures to the specific situation of particular species and ecosystems in need of protection. But this requires a completely new way of thinking about conservation.


“Our study helps raise important issues for discussion”


Are you questioning the validity of current objectives for urgent, effective protection of nature?

No, absolutely not! The scientific evidence shows an urgent need for action if we want to stop the rapid loss of biodiversity. This is precisely why it’s critical that a global strategy – requiring massive financial and human resources, and affecting all dimensions of sustainable development – be scrutinized by different scientific disciplines prior to implementation. Our study is the first to attempt to quantify the impacts on people. Of course, this sort of global calculation is very rough and says nothing about the various social consequences for different population groups. But it helps raise these important issues and – hopefully – sparks a nuanced discussion.


“Biodiversity protection should not further disadvantage people in poor countries”


What else do you think is needed other than an interdisciplinary approach?

It’s extremely important to include the voices of affected populations. In our view, biodiversity protection should not be achieved at the expense of poor people’s livelihoods – people who are already very disadvantaged, and who have also contributed the least to biodiversity loss. It’s the lifestyle and behaviour of people in wealthy countries, like ours, which are most responsible for this crisis. The participation of affected populations in discussions is also important because we need to focus on the most feasible measures possible. Time is short and resources are scarce. We need adapted solutions for different areas – solutions that also consider cultural specificities.


“Solutions are needed to stem negative consequences”


Negotiations are ongoing between the parties to the UN Convention on Biological Diversity over renewal of the biodiversity goals after 2020. What do you consider the most pressing issue?

The proponents of the strategy to conserve half the planet must now clearly show what areas would be placed under protection and under what conditions. Only then can science make more detailed predictions about the social, economic, and ecological impacts. In addition, it’s important to discuss the negative consequences of such a strategy and identify possible solutions. Lastly, it’s crucial that the parties to the Biodiversity Convention consider holistic and interdisciplinary approaches to nature conservation.

Protecting half the planet could directly affect over a billion people

Schleicher J, Zaehringer JG, Fastre C, Vira B, Visconti P, Sandbrook C. 2019

In: Nature Sustainability