We have got used to vast IPCC reports, but in the coming years tailored studies focused on land, cities and the 1.5C warming ceiling may be more useful to policy makers
This week in Nairobi, the Intergovernmental Panel on Climate Change (IPCC) will decide its agenda for the next 5–7 years.
At the top of the list is the Sixth Assessment Report, a comprehensive review to be published in 2021–22. But the most crucial work ahead involves shorter, more focused reports.
The IPCC brings together scientists and other experts from around the world to assess the state of climate science.
The IPCC’s work is important because it provides the scientific underpinning for climate policy, without being prescriptive. The findings are vetted by all the governments, so even if countries’ political priorities differ, they have a shared understanding of the science.
When world leaders approved the historic Paris Agreement last December, their actions were informed by the findings of the IPCC’s Fifth Assessment Report, published in 2013–2014 – including its warnings of potentially serious climate change impacts from even modest temperature increases.
Those warnings, combined with new science on sea-level rise and other risks, led some governments and civil society groups to argue that the target set at the Copenhagen Climate Change Conference in 2009, to keep warming below 2C, was no longer adequate.
After fierce debates in Paris, the Parties agreed “to pursue efforts to limit the temperature increase to 1.5C above pre-industrial levels.”
But does the science support a 1.5C target? And what might a 1.5C trajectory look like? How feasible would it be? How much would it cost?
We simply do not know – so in Paris, governments “invited” the IPCC to provide a Special Report in 2018 answering those questions.
Along with the 1.5C request, the IPCC has received 27 proposals for new Special Reports (though some overlap), on topics ranging from cities; to forests, land use and land degradation; to human health and food security; to oceans and the cryosphere; to aviation and shipping; to carbon markets.
It would be unprecedented for the IPCC to decline the Paris invitation, even though time is short to conduct and assess the research needed. Thus, in Nairobi, discussions will likely focus not on whether to prepare the report, but how.
The scope will also have to be carefully defined: For example, should the report also consider how a 1.5C target would fit with our knowledge of limits to adaptation, and how it might affect discussions about loss and damage?
That is likely to leave time for, at most, two additional Special Reports. There is a particularly strong push for a report on cities, which are increasingly recognized as key climate actors, and are hotspots for both adaptation and mitigation.
Given multiple related requests, another likely topic is land use and land degradation, which is also relevant to negotiations under the United Nations Convention to Combat Desertification (UNCCD).
All of this could delay the schedule for the Sixth Assessment Report, but that may not be a bad thing.
The IPCC has faced criticism that it works too slowly to meet policy-makers’ needs, and that the Assessment Reports are too dense and impenetrable.
In February, the IPCC hosted an expert meeting on communications that raised fundamental questions about the effectiveness of its reports.
Waiting until after the Marrakesh Climate Change Conference this November to set the agenda for the Sixth Assessment Report would give the IPCC time to consider possible new approaches, and to listen closely to the needs voiced by policy-makers and civil society.
The work ahead is daunting. The challenge now is how to be fast and nimble, to respond to the huge demand for the IPCC’s expertise, without compromising what the world values most in the IPCC: its deep commitment to scientific rigour and policy relevance.
Richard Klein is a senior research fellow at the Stockholm Environment Institute. He has been a lead author in six IPCC reports, including the last four Assessment Reports, serving three times as coordinating lead author.