Wageningen expertise in the IPCC climate report

Wageningen Climate Solutions

Photography: Shutterstock

BY Arjan Paans - September 2019

It is a time-consuming, labour-intensive ancillary function and the results often cause a fuss and spark controversy. But for Wageningen researchers, being a co-author on an IPCC climate report is one way of influencing national and international climate policy.

Earlier this year, a striking study by Swiss scientists made the news: the mass planting of forests around the planet would bring about a substantial reduction in the CO2 in the atmosphere, even down to levels last seen a century ago. The number of new trees you would need is huge but not impossible: 0.9 billion hectares, or twice the area of Europe.

The study shows the increasing interest in forests and forestry management in the climate debate, says Gert-Jan Nabuurs, professor of European Forest Resources. “I think that interest is a good thing because it draws attention to forests in the right way. But the figures are on the high side. Maintaining those forests sustainably requires a sustainable forestry sector with sufficient demand for timber.”

Forest and Nature Conservation is Nabuurs’ area of expertise. He is drawing on that expertise and knowledge as a coordinating lead author in the sixth climate report to be produced by the Intergovernmental Panel on Climate Change (IPCC). A total of 721 experts from 90 countries are working on the report by the United Nations’ advisory panel. They include two academics from Wageningen: Nabuurs and Public Administration specialist Robbert Biesbroek.

Dense forest with fir trees. The interest in forests and forestry is increasing in the climate debate. Photo: Shutterstock


Nabuurs is not exactly new to the IPCC. The professor was involved in four previous reports, twice as a lead author and twice as a contributing author. Now he is coordinating the chapter on mitigation. His working group is looking at what all the sectors in agriculture can do to combat climate change. Nabuurs: “Can we come up with realistic recommendations for concrete, feasible measures and what levers do policy-makers need to pull? While the forestry sector mainly sees opportunities for expansion, measures in agriculture will be more painful. It may mean that the price of food goes up, for example.”

This is Robbert Biesbroek’s first time working for the IPCC. The controversies surrounding global warming were a key reason why he wanted to get involved. “When the call came last year to submit contributions to the IPCC, I applied immediately. At a time of information overload and fake news, it is incredibly important for scientists to give politicians systematic, transparent support in taking decisions,” says Biesbroek.

While Nabuurs has a background in natural sciences, Biesbroek’s background is in public administration and policy studies. “The IPCC has been criticized regularly in the past for the lack of insights from the social sciences. I’m pleased that I will now be able to help them with my particular background. In my opinion, the climate challenge is a politico-administrative and societal challenge in which different groups frame the issue according to their own beliefs. Public administration and policy specialists can help expose those frames. They can also show what the options are for steering the process and how governments, the private sector and civil society organizations can meet their respective challenges.”

Floods are increasingly common in Bangladesh. Photo: Sk Hasan Ali / Shutterstock


Over the years, the IPCC has become a recognized authority around the world but it has also been the subject of controversy (see inset). As a result, the IPCC has started taking a much more professional approach, says Nabuurs. “I’ve been involved with the IPCC since 1999 and I’ve seen them start working with sound procedures for literature reviews and double checks to prevent any errors.”

Biesbroek too says that huge care is taken in the production of the report. “As a coordinating lead author, I am responsible for aligning the contributions from the various authors and the different chapters in the report. That is a very busy period in which you have to read an awful lot, summarize, aggregate and weigh up different scientific insights. That has to be done systematically, transparently and meticulously because IPCC reports are reference works that come under intense scrutiny from the moment they are published.”

The IPCC scientists need to beware of preaching hell and damnation. That leads to paralysis

Glaciers are melting as a result of global warming. Photo: Shutterstock


Rik Leemans, a professor of Environmental Systems Analysis, has some experience of the IPCC reports. He has been involved in various roles in a number of different reports since 1990 and has learnt what does and does not work. “The IPCC scientists need to beware of preaching hell and damnation. That only leads to paralysis as people conclude they can’t do anything to stop it. We need to offer governments the prospect of action. That means defining the preconditions for reducing emissions. Innovation can help you make the transition to sustainable energy, and tax measures should be taken to speed up that process.”

Leemans developed the ‘Reason for Concern’ diagram. That diagram presents the scientific arguments for the Paris Agreement, with its target of limiting global warming to two degrees Celsius. Leemans says reducing CO2 emissions to zero by 2050 is ‘definitely not impossible’. “It does lead to the question of who has the most right to those emissions: us, or developing countries that still have a long way to go to reach development. That is a solidarity issue. My personal and political perspective is that you need to share the burden equitably. But that doesn’t mean allowing those countries to become enormously polluted first. You can also achieve it by making the latest technology available quickly everywhere.”

We will still see rising emissions over the next 10 to 20 years, says Nabuurs. “You can’t easily change how land is used. And of course, countries such as China, India and Brazil will continue to develop. You can’t stop that. But it does mean the climate will continue to change. Perhaps it will take even bigger disasters before we feel pushed to take drastic measures.”

Christmas Island, located around 350 kilometres south of Java and Sumatra, is slowly disappearing as sea levels rise. Photo: Shutterstock


Working for the IPCC is not a minor job-on-the-side for the WUR scientists; it is a time-consuming, labour-intensive ancillary function. Nabuurs: “We have 15 authors working on just our chapter. I speak to them regularly, not only via Skype but also in person. We have already met up in Edinburgh and in September we will be seeing each other again in India. When you add in the other working groups, you have about 150 people flying all over the world for one report. Not very environmentally friendly for a report on climate policy, but it is necessary to reach a consensus.”

Planet Earth seen from space, with a view of the ice caps. Photo: Shutterstock

The increased attention being paid to climate change has also made compiling IPCC reports a bigger endeavour than it was in the past. Biesbroek: “There has been a huge increase in the scientific literature in recent years. As a result, taking the relevant literature into account in the analyses has become an enormous challenge.”

That is also partly what makes for such an impressive final product. “The value of the IPCC is that so many scientists get involved and assess the facts. This gives you a very thorough report that has broad support.”


The IPCC started in 1988. It was set up by the UN Environmental Programme (UNEP) and the World Meteorological Organization (WMO). Its task is to collect scientific data on climate change and assess the consequences. The IPCC also advises governments on the options for dealing with the problems (mitigation) or on alterations that let them cope with the consequences of climate change (adaptation). The IPCC publishes reports every five to six years.

For more information about how WUR explores the impact of climate change on society and ecosystems, please visit our website.

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