Karen Timmermann. Foto: Andreas Frommelt

The climate crisis and the biodiversity crisis are interlinked

Wednesday 29 Jun 22


Karen Timmermann
DTU Aqua
+45 93 51 03 81

Series on biodiversity

The 2022 UN climate report stated for the first time that efforts to protect the climate and biodiversity cannot be separated.

In this connection, we’re focusing on the question 'What is biodiversity?' in a series of articles. A number of DTU Aqua's researchers will give their answers.

Professor Karen Timmermann - an expert on impacts of nutrients on coastal waters, and a member of the Danish government's Biodiversity Council - speaks about biodiversity and natural processes.

Marine biodiversity has not been given as much attention as biodiversity on land, but fortunately this is now changing, says  Karen Timmermann. Dr Timmermann is a professor at DTU Aqua, an expert in nitrogen and coastal seas, and a member of the Danish government’s Biodiversity Council. She is the second in the line of researchers that we ask to answer the question What is biodiversity?

According to Karen Timmermann the keyword is processes.

“My personal view is that biodiversity is both about the diversity of species and the diversity of habitats as well as the diversity of ecological processes. In the ocean, this include processes like  metabolism, photosynthesis, and the burial of carbon.”

“When biodiversity declines, we lose some of the natural processes that can also benefit humanity,” says Karen Timmermann.

The sea makes up most of the surface area of Denmark. The EU Marine Strategy Framework Directive from 2008 has directed attention to the fact that the nature of the seas has to be  protected.

Until marine biodiversity became a cause, the political and scientific focus was on the marine environment, i.e. on water quality—is there enough light, is there a problem with oxygen depletion and algae blooms that we need to address? 

The landfill

“Marine biodiversity has always been part and parcel of my work,” says Karen Timmermann, who did her PhD thesis on worms in the seabed. But it all began with a walk in the woods. 

“I remember going on a school camp in France. A friend and I went for a walk in these incredibly beautiful woods. But we got lost, and all of a sudden we came face to face with this huge landfill—in the middle of the forest! I was outraged—and the experience is still with me.”

"When I was a child, it was generally believed that the ocean would erase all traces of pollution. Pollution was an insignificant drop in the big ocean. Science has documented that this is not the case. Man-made pollution has significant effects on life in the oceans."
Professor Karen Timmermann

“I started thinking about the fact that landfills are very visible, but what about the sea? How do humans affect the sea? The seas around Denmark are amazing, and I decided that I wanted to explore  the impact of  human activity on coastal environments,” she says, going on to describe Denmark: 

“From a global perspective, the Danish countryside is not all that interesting biodiversity-wise. But the sea is quite a different matter! We have shallow inlets, bays, belts, and coves, and we have sandy seabeds, dunes, and salt marshes! Most coastal areas around the world are rocky shores with crashing waves and deep waters. So our coastal areas are completely unique types of nature  on a global scale!"

Close, but at arm’s length—the government's Biodiversity Council

Karen Timmermann is a member of the new Biodiversity Council established by the Danish Minister for the Environment in autumn 2021 to advise the Danish government and the Danish parliament.

How far have you come?

“We’re in the process of identifying the most pressing problems for the Danish biodiversity.  The council will be looking into conditions on land, in freshwater environments, and in the sea, and assess  how protected nature really is and identify disturbances to habitats and of species.” 

Why is protecting marine biodiversity important?

“For two reasons, I would say: One is that organisms and habitats have value in themselves. In my opinion, we have an obligation to protect nature. And not necessarily for our own benefit.” 

“The other slightly more selfish reason is that high levels of biodiversity mean that we have a lot of ecosystem services that contribute to human well-being, i.e. more fish to catch, coasts that are better protected against global warming and flooding, and more resilient ecosystems. A system with few species and impoverished habitats doesn’t provide the ecosystem services it should, and it is more vulnerable to devastation—and then everything is gone,” says Karen Timmermann. 

“The role of the Biodiversity Council is to be critical of the  initiatives proposed by politicians, and our mandate is to keep an eye on whether the steps that are being taken promote biodiversity. We are nature’s watchdog.”

Karen Timmermann emphasizes that even though the Biodiversity Council has been established to advise the government and Danish parliament on nature and biodiversity, the council is an independent of body. 

Biodiversity and fisheries 

Given her role as a member of the Biodiversity Council, Karen Timmermann is looking forward to establishing closer collaboration with research colleagues at DTU Aqua: 
“I see before me a professional forum at our department where we can discuss various aspects of marine biodiversity. What is biodiversity?. What are the threats? And what are the solutions that can contribute to an increased biodiversity in the ocean? Some people here at DTU Aqua have huge knowledge about this, and we have some of the best people in Denmark in the field of marine and also freshwater biodiversity." 

“And, of course, I will be able to draw on DTU Aqua’s competencies when it comes to the interactions between  fisheries, fish populations and marine biodiversity in general. DTU Aqua has researchers who are among the most knowledgeable in this field,” says Karen Timmermann. 

The good example 

What will it take for research to really have an impact on policy decisions?
“First of all, politicians must genuinely want their decisions to be based on solid knowledge,” Karen Timmerman replies and continues: 

“As a researcher, you sometimes wonder how they can make the decisions that rest on a fragile foundation —but of course it is their right and sometimes necessary. Other times, for example when it comes to biodiversity, I actually feel that our politicians are very keen for their decisions to be based on knowledge, which is a prerequisite if we want to stop the loss of biodiversity.” 

The human dimension 

But when can the marine environment be said to be in a good environmental state, as they say in the Marine Strategy Framework Directive? What do scientists compare with—what is your baseline?

“Well, basically ... my take is that there is no baseline—but try to think what biodiversity would be like in a world without humans," says Karen Timmermann. 
Is that possible—figuring out the ecological state of a world without humans?

“You can try. For example, attempts are being made to calculate how deep eelgrass would have grown if there were no human impact. We’re trying to see how far back in time we can go based on historical data to see what the distribution of eelgrass would be in a situation that was fairly unaffected by human activity. When it comes to coastal areas , we typically look at the impacts of eutrophication, i.e. the effects of an increase in the supply of nutrients, which is what I specialize in,” says Karen Timmermann. 

She points to certain times in history when human activities have led to a substantial increase in the leaching of nutrients to the oceans, thus affecting ecosystems. For example, when humans started to farm the land intensively. And when we built cities and had no wastewater treatment plants. 

“Some people would say, well aren’t humans part of nature? And of course we are part of nature, but we are also the ones who influence what we call the natural processes the most. And for me, it’s interesting to find out what biodiversity would be like without disturbances from human activities,” says Karen Timmermann.

How do Darwin and the survival of the fittest come into the picture? 
“The way I see it, every kind of human activity involves a risk of disturbing the natural processes. And if we did away with these disturbances, then evolutionary processes would lead to other losses and in all likelihood a loss of biodiversity. Humans can easily survive in a less biodiverse world—but it will be another world. That’s for sure.”

The two biggest crises we face

Do you still believe that your research can make a difference? 
“I have a fundamental belief that knowledge makes a difference, and that researchers have an obligation to try to make a difference by providing knowledge to society,” says Karen Timmermann.

“When I was a child, it was generally believed that the ocean would erase all traces of pollution. Pollution was an insignificant drop in the big ocean. Science has documented that this is not the case. Man-made pollution has significant effects on life in the oceans. It’s the same story for the climate. Until recently, it has been an almost absurd idea that human behavior could affect the entire climate system. Science has shown that we can. And even though this knowledge might be inconvenient, it is a prerequisite for us to be able to do something about the problems,” says Karen Timmermann. 

The UN’s second report on the state of the climate, which made grim reading, was published in February and made it clear that the climate crisis and the biodiversity crisis are inseparable — What do you say to that?

“I don't think they are inseparable—but they are interrelated and I don’t think one should look at them in isolation,” Karen says, explaining:

“If we don't acknowledge their interrelatedness, we risk exacerbating one crisis to overcome the other. For example, planting a lot of “climate forest” is not necessarily good for biodiversity. And poor biodiversity will exacerbate the climate crisis because natural processes, such as carbon burial, are disrupted. You have to find solutions that benefit both the climate and biodiversity.” 

“That said, I think those are the two most important crises we could be facing. And they are both aggravated by human behaviour. So given that they are driven by the same causes, we should try to find common solutions—and protecting and restoring natural habitats is a key effort when it comes to getting nature to help us solve the climate crisis." 

What do you hope your research will have done for biodiversity in 10 years’ time?

“I hope that in 10 years’ time we will have provided  the  conditions for improved marine biodiversity. I see my role as that of presenting knowledge about what it will take to ensure good marine biodiversity and healthy coastal ecosystems.” 

“We have moved on from the idea that we can pollute the ocean  and exploit the world’s natural resources without a second thought for the consequences, to still polluting  and exploiting the world’s resources, but now thinking about the potential consequences and reduce the negative impacts. And we’re constantly gaining more knowledge and collecting more data on the environmental impacts and the role played by human activity, enabling us to make for informed decisions on how to balance the protection and utilization of marine resources,” 
concludes Karen Timmermann. 

Photo: Andreas Frommelt

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Karen Timmermann holds a Master’s degree in mathematics and environmental biology and a PhD in environmental biology from Roskilde University (RUC). 

In 2006, she was appointed as postdoc at the then National Environmental Research Institute, which subsequently became part of Aarhus University. She was appointed to a researcher position in

2007, and she became a senior researcher in 2010.

In 2020, Karen Timmermann was appointed professor of biogeochemical modelling at DTU.

At DTU, Karen Timmermann works with the processes that control the development of marine habitats and ecosystems, and she investigates which instruments can be used to improve the state of the environment and restore habitats in the coastal zone. She leads the research on which the Danish river aquatic environment plans are based, which will ensure a good ecological status of Danish coastal waters. 

She has received research funding from Innovation Fund Denmark, the Velux Foundation, and other foundations for studies into measures that can improve coastal zone environments and reduce the negative impacts of human activities.

For the past ten years, she has been advising authorities and politicians on the Danish aquatic environment, and she is a member of the Biodiversity Council, which advises the government and the Danish parliament on initiatives in the area of nature and biodiversity.