Cause and Effect | ‘Scientist’s job isn’t to negotiate, but to give evidence to govts’: Aditi Mukherji, IWMI

The Intergovernmental Panel on Climate Change, or IPCC, convened for a four-day session on Tuesday to begin the next round of what is known as the assessment cycle. Established in 1988, IPCC is the scientific authority on the climate crisis, bringing the most detailed, evidence-based picture of how the Earth’s climate is changing in its assessment report (AR). These reports cover in fine detail the technical, economic and social factors, and consequences of the climate crisis. The meeting, which will go on till Friday, in Nairobi, Kenya, will begin work on the AR7, or the seventh assessment report, which is likely to be drawn up in 5-7 years.

In an interview with HT, Aditi Mukherji, director, Climate Adaptation and Mitigation Impact Area Platform, International Water Management Institute, who was among the authors in the outgoing AR6 cycle, explains the process of the compilation of the reports and how consensus is built over intricate technicalities, and addresses the key question on how the bureau approaches the years-long gaps that exist between each AR.

What is the process of compiling IPCC reports?

Members of the IPCC bureau that are elected by respective governments meet at the beginning of the assessment cycle, scope out the various reports, and come up with a structure for the report. Then governments and various other organisations, including international and intergovernmental, who have nominating rights then pick authors. The bureau members then select those authors based on requirements of expertise, gender, geographical coverage etc. The diversity of authors is an important consideration for IPCC. Once the author teams are selected, the writing process starts. Each report takes two to three years to compile. Usually, there are three working group reports and special reports.

What was the timeline of the AR sixth report?

The sixth assessment report started in 2015 and it was finished in 2023. It was scheduled to finish in 2022, but it was postponed by a year due to the Covid-19 pandemic.

When did the work on the report end?

There were six reports in this cycle, and each one had a different cut-off date. The final cut-off date for the working group 2 and working group 3, which was the later end of the cycle, was around October 2021, while the synthesis report came out in March 2023. There is a gap between the publication and the cut-off dates. But wherever possible, updates are included as footnotes, or we clarify that the cut-off date was such and such.

What consensus-building exercises are employed before the final report is published? We have seen lots of political friction at climate summits over the last couple of years. Does that happen with IPCC reports as well?

The individual chapters and the technical summary are purely scientific documents and the authors’ job is to assess the current state of the scientific literature. In these documents, the governments review and provide comments, but the final decision on whether or not to accept the comments is based on the science and lies with the author team. The consensus process comes in only for the summary for policymakers which is a document that is developed jointly by scientists and countries. Here again, the scientists’ job is not to negotiate but to provide the best available evidence so governments can agree on the wording that suits their positions. But those positions have to be scientifically supported.

Considering the enormity of the exercise, and the fact that the reports are published 10 years apart, do you think by the time the final reports are published the numbers might be outdated?

No, the final numbers are not really outdated, though there could be some minor changes. For example, when it comes to warming, our report says 1.07°C which was rounded off to 1.1°C, and now we are talking around 1.15°C which is rounded off to 1.2°C. This update is provided as a footnote in the synthesis report [published on March 20, 2023]. When it comes to mitigation targets because our cut-off date was October 2021, the targets declared in COP26 in Glasgow and then COP27 in Sharm-el Sheikh could not be included, which meant that some of the latest pledges were not a part of the reports. But, the basic science, that there is a climate crisis and rapid action is needed, remains unchanged.

Is there a way to rectify it, or even update some key indicators, at say the halfway mark?

IPCC does not conduct original research; it only assesses available evidence. Scientists keep updating these numbers anyway and these are published in the form of new papers, so if anybody wants to track what is happening with global warming, there is a large body of scientific papers they can refer to.

Historically, there has been a lack of data from the Global South. Is that still the case?

There is certainly an issue of quality of data and amount of data from countries in the Global South. Increasingly, India and China are doing well. In terms of climate data, the gap remains mostly from African countries. So, if you look at maps of the working group one report, you will see a lot of data gaps remain in Africa.

There is a scope for further investments into hydrometeorological observation stations for collecting better climate data. The same applies to integrated assessment models which are used for future scenarios. Much of the work happens in universities in the Global North, and assumptions made are not always equitable. There is a scope for far more work on this.

Is India also behind the curve?

No, I think there was a lot of literature reflected from India and South Asia. India did very well in working groups 1 and 2, and the kind of work which is the physical basis of climate change. There were many Indian authors who worked on the IPCC report as coordinating lead authors (CLA). Water chapters in both working group 1 and working group 2 had Indian CLAs. However, as I mentioned earlier the global integrated assessment models which are used for working group 3 need more perspectives from our region.