Sonia Yeh
Sonia Yeh, one of the co-authors of the new IPCC report. Her fields of research centres on alternative transportation fuels, consumer behaviour, urban mobility and sustainability standards. Her research has made her an internationally recognized expert on energy economics and modulation of energy systems. Photo: Anna-Lena Lundqvist​​​​​​​​​​​

IPCC – "We are in the middle of the transition"

​“The IPCC collects and reports about the state of knowledge in science, technical and socio-economic assessments on climate change. Everything we write in the report is not new scientific discoveries. The main aim is to bring this knowledge to policymakers and the general public in a comprehensive, clear and accessible way”, says Sonia Yeh, who contributed to UN’s Intergovernmental Panel on Climate Change´s (IPCC) report, which was presented on the 4th of April.​
WG III, is the final part of the IPCC’s Sixth Assessment Report, and it focuses on climate change mitigation, assessing methods for reducing greenhouse gas emissions, and removing greenhouse gases from the atmosphere. 

“So the main challenge for us as scientific contributors is the writing. How do you communicate in a clear and unbiased way, what information to include or to exclude, how do we coordinate across chapters so there is consistent and no overlapping messages, etc.”, says Sonia Yeh, Professor of energy and transport systems at Chalmers University of Technology. 
Her expertise is in energy economics and energy system modelling, alternative transportation fuels, sustainability standards, technological change, and consumer behavior and mobility. She has contributed to IPPC report, Working Group III Mitigation of Climate Change, Chapter 10 Transport in the subchapter “Scenarios from Integrated, Sectoral and Regional Models”.

What is it that makes you take on such a big assignment like this?
“On one hand, it is indeed a huge time commitment. So, one must decide beforehand how much time one can spare to be involved in such a big effort. On the other hand, it is a huge honor as a scientist to be selected to represent your country to co-produce such an important document. The document is the most comprehensive assessment effort roughly every 6 years providing an update on climate mitigations options. It has tremendous societal values to both policymakers and all concerned citizens around the world”, says Sonia Yeh.

Her path to be selected as an IPCC contributing author was a bit unconventional. The typical path for being an IPCC author was for one to first self-nominate, then being selected for nomination by your country. 

“I joined the IPCC process in the middle as I received a phone call one day by the lead author of the chapter on transport scenario asking if they can rely on my competence in the long-term projections of transport scenarios. That’s how I joined in the middle of the process. So there is a separate path to be asked to join as an contributing author if the lead authors consider your technical expertise is critical for part of the report”, says Sonia Yeh.

What sets this report apart from previous reports?
"I cannot talk about any specific details before the release. But certainly, one of the most interesting things writing up this report is to observe how things have changed from this report from the last (5th Assessment Report), which directions and how fast the changes were. Lots of things have changed: technology costs and their commercial availability, demand growth, new technology, system level interactions, etc. As someone said, around the time of the last report, we were talking about the transitions. At the time of the writing of this report, we are right in the middle of the transitions. So we are certainly seeing lots of changes (both expected and unexpected) so that would be something interesting to watch out for when the report is released". 

What is the biggest challenge for you as a researcher working on the report?
"The IPCC collects and reports about the state of knowledge in science, technical and socio-economic assessments on climate change. Everything we write in the report is not new scientific discoveries. The main aim is to bring this knowledge to policymakers and the general public in a comprehensive, clear and accessible way. So the main challenge for us as scientific contributors is the writing. How do you communicate in a clear and unbiased way, what information to include or to exclude, how do we coordinate across chapters so there is consistent and no overlapping messages, etc." 

What are the most important conclusions you can draw from your work, on a purely personal level?
"The main thing I learned is the self-reflective part that I mentioned above regarding what sets this report apart from the previous reports. In a way we are asking on behalf of the public, How has science changed in this report compared to the last, how things have changed, are the challenges we face today different from the challenges we faced 4 years ago? Unfortunately IPCC mainly addresses the question of “what do we know today” rather than the question of “what has changed compared to the last assessment.” This is understandable. To answer the latter question comprehensively, it requires greater efforts conducting rigorous studies and IPCC is not set up to do that. Nevertheless it is a question I ask myself frequently while writing for the report, and I am sure that you will see a lot of discussions in the blog posts, tweets, and news columns on this later question a lot. One should be careful and take these discussions with a grain of salt though since most of them are produced quickly to provide discussion points in the news media and for the public discussion. Therefore they are good food for thoughts but one must understand that IPCC does not formally analyze such a question", says Sonia Yeh.

When it comes to the most important measures to reduce the climate impact of the transport sector, Sonia Yeh recommends the seminar, IPCC Sixth Assessment Working Group III report on Climate Mitigation: Where are we in the transitions? It´s a public online seminar and several of the authors of the report will participate.

“The important thing to know is that there is no silver bullet. Reducing CO2 emissions from the transport sector cannot rely on a single technology, one behavioral change or a single policy measure. Exactly how much a role different measures can contribute will depend on the region, time frame, the commitments of the governments and individual actions. The chairman of the IPCC says that IPCC is policy relevant, but not policy descriptive. IPCC does not tell policymakers or the citizens what they should do, but what they could do to reduce greenhouse gas emissions, and the impacts of different actions in terms of potential for emissions reductions”, says Sonia Yeh.

When do you think the energy will be fossil free for all transports?
“My personal reflection is that the transport energy will not be fossil free without strong policy measures. Meaning, policymakers will need to take actions to introduce policies such as carbon tax or carbon caps, incentives, standards and regulations, investments in low-carbon technology and transport infrastructure that supports zero-carbon fuels and vehicles, charging infrastructure for electric buses, cars, trucks, ferries, etc. So there is a lot to be done. But it is like “The Little Engine That Could”, we can do it! And I believe that we have the momentum. It is just a matter of how fast we want to do this”, says Sonia and highlights an example of how fast things have changed in the last few years:
"A few years back, most people think the only viable ways to decarbonize long-haul trucks are biofuels and hydrogen. But as the price of batteries falling faster than expected, electrifying long-haul trucks are becoming real and attractive possibilities. The only hinder is the build-up of the charging infrastructure, which of course is an intensive research area that we at our group are also working actively with many European partners. Many excellent research groups at Chalmers are also studying this from many angles including materials, batteries to system level integration like the grid impacts in Sweden and in Europe”.
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Page manager Published: Tue 05 Apr 2022.