Skip to ContentSkip to Navigation
Part of University of Groningen
Science LinX Science Linx News

‘We have wasted two crises’

Klaus Hubacek is Lead Author in the sixth IPCC climate report
04 April 2022

On 4 April, the third working group report of the sixth IPCC assessment cycle was published. One of the Lead Authors for this part of the sixth IPCC climate report is Klaus Hubacek, Professor of Science, Technology, and Society at the Energy and Sustainability Research Institute Groningen, at the Faculty of Science and Engineering of the University of Groningen. He specializes in consumption-based emissions of greenhouse gases. ‘We could have used the corona pandemic to invest in sustainable alternatives, but that didn’t really happen to the required extent.’

The last days before the publication were rather busy. ‘We still had to negotiate some texts. The way in which the scientific findings are summarized can be quite political,’ Hubacek explains. ‘As scientists, we must watch that these summaries reflect the science.’ He and the other authors received some brief media training before the release. ‘In the weeks before the publication, we were already getting questions about our contributions.’

Klaus Hubacek | Photo University of Groningen
Klaus Hubacek | Photo University of Groningen


The IPCC produces a new assessment report every five years or so. For each new report, a group of Lead Authors is appointed, often put forward by research institutes or governments. ‘You are then involved in the entire five-year cycle. As Lead Authors, we are involved in a particular chapter and within this chapter we take the lead in writing specific sections.’ Hubacek’s chapter carries the title ‘Emissions trends and drivers’ and he is involved in two sections that cover changes in emissions but also specific topics on emissions of rich versus poor countries, differences in carbon footprints within countries, the impact of trade and the possibility of decoupling greenhouse gas emissions from economic growth.’

Lead Authors are appointed by the IPCC but there are also contributing authors with specific knowledge, who can be invited by a chapter group. Hubacek invited his ESRIG colleague Yuli Shan, a Research Fellow in Climate Change Economics, to contribute to his sections. ‘He has his own specialty but he collaborated on all the topics that I was involved in.’ Overall, there are 278 authors for the second chapter of the third working group report.

Hubacek was selected while he was still at the University of Maryland (USA) at the start of this sixth cycle, before he moved to the University of Groningen. ‘I had previously been invited for the fifth cycle, the report that called to limit global warming to 1.5 degrees Celsius, but that was at an inconvenient time. I have really enjoyed being part of this new cycle.’ The first two meetings on setting the goals for the report and an early review, took place before the coronavirus pandemic. ‘So, we were able to meet in person twice. I enjoyed this very much, seeing old friends and making new ones. It was good to meet so many people who care about the climate.’

Yuli Shan | Photo University of Groningen
Yuli Shan | Photo University of Groningen


Authors are selected to provide a wide range of views and expertise. Everything that is written has to pass several reviews. ‘And we have to address all the comments that we receive. The process is very thorough. I’m happy that I could also contribute to the science, with several of my papers.’ He is less happy with the way that climate change is tackled. ‘It makes me sad for my eleven-year-old son, who may have fewer opportunities and more problems than my generation if we do not take appropriate action now. The report is clearly showing that we can still achieve ambitious targets but also that this window is closing quickly (in fact, within the next couple of years). ’The victims of our potential inaction will be future generations and the more vulnerable sections of society and countries in the Global South.’

Hubacek notes that there is great inertia in the climate system and in political action. ’Damage to ecosystems and ice caps will not just stop when we reduce emissions.’ Some changes, such as the extinction of species and the loss of biodiversity, are irreversible. ‘And’, he adds, ‘we have wasted a good crisis and are about to waste a second. We could have used the coronavirus pandemic to invest in sustainable alternatives but that didn’t really happen to the required extent.

With simple behavioural changes, the EU could compensate for lost oil imports from Russia.
With simple behavioural changes, the EU could compensate for lost oil imports from Russia.


The world is now faced with another crisis now that Russian gas and oil deliveries are reduced because of the invasion of Ukraine. With simple behavioural changes, the EU could compensate for lost oil imports from Russia. Bringing down the speed limit on motorways is just one example. Investing in renewables is another. The co-benefit would be an increase in energy security.’ Hubacek regrets that the military sector is absent from the report. ‘They are big emitters but no goals for reduction are set for this sector.’

Another important conclusion from the new report is that decoupling of emissions from economic growth is possible, but only for the richest countries. ‘Some 18 nations have achieved this, many of which are very high income countries. This is not a model that could be implemented globally. I think that economic growth outpacing emissions hasn’t worked that well in the past.


The new report provides new data and trends and should spark fresh debates on how to limit climate change. And, for the first time, a chapter on the social aspects of mitigation is included. A new chapter on social aspects of mitigation that will explore the ‘demand side’ - what drives consumption and greenhouse gas emissions - was added. Linda Steg, Professor of Environmental Psychology at the University of Groningen is one of the Lead Authors. Hubacek: ‘There are all kinds of dilemmas there.’ Overall, the report shows that a lot of different measures are required to bring greenhouse gas emissions down. ‘There isn’t just one silver bullet that will solve all of our problems.’

Last modified:27 June 2024 3.55 p.m.
View this page in: Nederlands

More news