Scientists consider how to make ever-longer IPCC climate science reports an easier read

British chemist Robert Watson had strict instructions when he sat down to write the opening chapter of the first U.N. scientific overview of climate change in 1990: “Keep it short.”

On Monday, the sixth set of reports by the same U.N. panel hit a record length of more than 10,000 pages, with the release of a third section of almost 3,000 pages on solutions to climate heating, showing it is “now or never” to head off the worst.

By contrast, in 1990, the initial report series by the Intergovernmental Panel on Climate Change (IPCC) totaled a relatively modest 1,000 pages.

“This is ridiculous — I would almost use the word,” said Watson of the ballooning length he believes makes the reports impossible to digest.

A surge in research about climate change in the three decades since 1990, when the science was in its infancy, is raising questions about whether the IPCC needs an overhaul to keep up with new literature.

About 70 new scientific studies every day mention climate change or global warming. Suggestions to make them easier to monitor include using computers to take on jobs currently done by humans, or shifting to a Wikipedia-style format of constant updates rather than huge assessments every few years that risk getting quickly outdated.

Watson, chair of the IPCC from 1997-2002 and a U.N. panel on biodiversity from 2016-19, said he wanted to be “provocative and constructively disruptive” of long-windedness, while insisting the IPCC is the gold standard to guide government policies.

Watson said his bosses in 1990, including then IPCC chair Bert Bolin of Sweden, were adamant about concision. “It was the best decision. … Shorter is actually better,” Watson said.

The opening chapter he wrote back then with three colleagues about “greenhouse gases and aerosols” ran to 40 pages, including illustrations and references.

Thelma Krug of Brazil, one of three current IPCC vice chairs, disagreed with Watson’s criticism, noting that governments had asked for comprehensive information in an area of science now touching all parts of society, including agriculture, energy, industry, health and economics.

Research explosion

“The literature is becoming so abundant in all areas,” she said. “The contents are so innovative, so important.”

While few people read the full text of the IPCC reports, she said governments, scientists and anyone else can download them free and search for their topics of interest.

And, she noted, the three main sections of the IPCC assessment report series each have a summary for policymakers, limited to a few tens of pages.

Those are endorsed line-by-line by governments, securing agreement among nations as disparate as OPEC oil exporters and small island states at risk of sea-level rise.

Monday’s IPCC report on solutions to global warming ran to 2,913 pages on the need for deep, unprecedented cuts in greenhouse gas emissions by 2030 and other reforms to get on track for the 2015 Paris Agreement goals to curb climate change.

The latest installment follows a 3,949 page report last year about the science of global warming, which the U.N. chief called “code red,” and a second one this February about the impacts of warming and how to adapt to them, running to 3,676 pages.

A synthesis report, tying up all the themes, will also be published in late 2022.

“It’s a wonderful scientific document,” Watson said. “But there’s not a government in the world that’s going to read 3,000 pages.”

The IPCC reports would be more accessible if condensed to 100 pages, he suggested.

One massive difference is that in 1990, the IPCC only had 327 academic studies to assess, said Corinne Le Quere, a professor of climate change science at the University of East Anglia.

Since the last IPCC cycle in 2013-14, researchers who work on its reports have had to review 230,354 studies, she said, based on the Web of Science database.

Work done for the IPCC is unpaid, but prestigious — the panel shared the 2007 Nobel Peace Prize.

Child of the 1990s

“The method of the IPCC for doing these assessments is a child of the 1990s. It’s not a child of the 2020s,” said Le Quere. “Now we have data science, we have machine learning, we have language interpretation. The IPCC needs to take advantage of this. It’s essential to have the IPCC as an authoritative voice, but there must be an evolution,” she added.

In 1990, the IPCC found the Earth’s climate was changing but it was not yet possible to conclude whether the shift was caused by greenhouse gases from human activities or by natural cycles.

Last year’s IPCC report said it was “unequivocal” — beyond a shadow of doubt — that human activities are the main drivers of global warming, which is stoking heatwaves, droughts, floods, species extinctions and rising seas.

Le Quere is director of ScienceBrief, which visualises climate science to help researchers, and has suggested it could be widely used by the IPCC.

A review of more than 150 studies of wildfires, for instance, says there is a “clear consensus” that “climate change increases the risks of wildfires.” Another identifies a “moderate consensus” that “climate change is probably increasing the intensity of tropical cyclones.”

With ScienceBrief, each topic is judged by showing all published studies as dots on a graph, ranging from “refutes” to “supports” a given hypothesis. Readers can click on each dot to get to the underlying scientific study.

Reviewing the explosion of scientific literature “is not a human task any more. … You can’t keep up,” Le Quere said.

Other systems using data include work by Jan Minx, an IPCC author who has argued that climate science and policy need a new approach for an age of “big literature.”

In other fields, the COVID-19 pandemic has shown how scientists can tap vast amounts of data to help develop vaccines at record speed.

But Krug of the IPCC expressed concerns that greater reliance on computing could put researchers in developing nations at a disadvantage, as they often have less access to technology. About 40% of the authors of the latest report are from developing countries.

Krug said governments would have to agree on any reforms. Among suggestions are to reset the IPCC timetables to match the five-year policy reviews mandated in the Paris Agreement, or to tie up more closely with other U.N. assessments, such as those of biodiversity.

Britain’s Royal Society will host IPCC leaders and other experts at a conference next week to discuss policy and research needs.

Krug, who plans to retire after 20 years with the IPCC, said she clearly favored one key reform: appointing a woman for the first time as chair of the U.N. climate science body after its current head, Hoesung Lee of South Korea, stands down.