"There is no easy return to a beautiful yesterday"

Biodiversity – the diversity of ecosystems, organisms and their interactions – is threatened as never before, despite all efforts. In this interview, biodiversity expert Helmut Hillebrand of the University of Oldenburg, Germany, talks about 30 years of the Rio Convention and the central role biodiversity plays on our planet.

Prof. Hillebrand, why is biodiversity important for us humans at all?

Almost all processes on Earth we as humans depend on – the oxygen we breathe, the food we eat – are biological achievements and are directly related to biodiversity. Without biodiversity, there is no human life. And: biodiversity is the defining feature of our planet. This also results, I believe, in an ethical obligation to protect biodiversity.

The first Convention on Biological Diversity (CBD) was ratified as early as 1992. The so-called Rio Convention was the first global legal framework for the protection of biodiversity.

Yes, and the fact that the Rio Convention came about was something extraordinary and was highly celebrated at the time. The ratification triggered an important process...

Nevertheless, in a 2019 report, the international scientific body IPBES stated: "Biodiversity – the diversity within species, between species and of ecosystems – is declining faster than at any time in human history." Has nothing improved since the first convention?

Yes, unfortunately. And it gets even worse. The states that signed the convention had adopted the so-called Aichi Targets in 2010. The goal was to limit biodiversity loss by 2020. But the report on this, which was published in autumn 2020, had to state: We have not achieved a single one of these goals. One of the goals, for example, was to reduce the global extinction rate of species. And we didn't manage to do that – even though we invested a lot in nature conservation.

Why is that?

The problem is threefold. First, the additional investments in protected areas have been eaten up by increased pressures on the environment. We have not reduced the pressures on biodiversity caused by land use, pollution or overuse. The second thing is: biodiversity constantly changes. There is no easy return to a beautiful yesterday of any kind, because the nature of interactions between organisms is diverse and complex. And thirdly many measures that make sense in principle – for example, giving an area a protected status – cannot be adequately implemented and monitored. Often, there is a lack of resources and personnel. This is a huge problem with marine protected areas, for example.

According to the CBD, the vision for 2050 is to "live in harmony with nature".  How can this be achieved?

That is of course a relevant goal. But it is not measurable. What does "living in harmony with nature" mean? How can we tell when we are doing it? And which steps that are measurable would be the right ones? We need to question this. For example, there is the 30-30 target. This means that 30 percent of the world's area should be protected by 2030. The question is: Who selects these areas? And what does that mean, for example, for the developing countries’ perspectives? Plus, putting an area under protection does not mean that this will be accepted, monitored and sanctioned. So, we need targets along the way that are measurable, that can be implemented with management measures and that many can agree on. That is the enormous difficulty. We can only solve this globally – similar to the climate crisis. Of course, this also means that there has to be a lot of discussion about balancing interests. In order to achieve that we need a framework like the CBD, and the IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services), which summarises the state of the science.

Are there any positive examples of how such protection can succeed?

For example, it is a great asset that a large part of Germany's Wadden Sea coast is under protection. High effort is made to monitor the area and assess its condition. But there are also limits: Certain activities are not prohibited, such as fishing, shipping and so on. And we can't protect the system from certain influences, such as warming or inputs via rivers. So, it is not enough to protect only one part of the system. Also, it is not about defining an ideal world. There is no such thing as nature unaffected by humans. We can only reduce impacts and we have to think of nature together with people and not nature against people.

The topic of climate change, for example, plays a big role in public debates, but the topic of biodiversity not so much. Why is that?

I think it's because of two things. The first is: when we talk about climate, we talk about things that every person immediately understands, for example temperature. We have a scale, and we know: 20 degrees Celsius is warm, five degrees is cold. Biodiversity is a very complex property of living communities. You can count how many different species there are, or look at how interconnected these species are. There are many different aspects of diversity that are not as easy to communicate as temperature. Secondly, biodiversity change is much more complex than climate change. Of course, the climate system is also complex. But what we are seeing is an increase in temperature. What we see with diversity is that some species go extinct while other species are coming in. The dominance of species is changing. And all these aspects are happening simultaneously. So we have a very diverse happening that you can't just show with a curve, for example.

How can we draw more attention to the importance of biodiversity?

From my point of view, it is important to impart knowledge about biodiversity. Not only in schools, but also in further education. We have to work towards people understanding what biodiversity actually is. Because recognising how nature changes is not like feeling a warming on your skin. You have to go there and look at it. But often we take nature for granted – the fact that something grows and we have food. But the fact that fruit, for example, does not grow without pollinators and that in areas where pollinators have become scarce, we have to pollinate by hand, is an example that shows how important biodiversity is. The crucial point is: biological diversity plays a central role for us humans, we are fundamentally dependent on nature. We must recognise and appreciate this.