‘Hours on a footnote’

After spending hundreds of hours in virtual meetings to complete this week's major UN climate report, scientists Piers Forster and Joeri Rogelj celebrated in a way their peers could not: by hugging. 

Britain-based Forster had been weary of the isolation during the COVID-19 pandemic and invited his co-author to work alongside him in his Harrogate kitchen as they worked with other scientists around the world to thrash out the final version of the report by the Intergovernmental Panel on Climate Change.

Being together for the last stretch of a three-year effort "made it more fun," said Forster, a climate physicist at the University of Leeds.

Specialist scientists, all 234 of them working for free, reviewed more than 14,000 scientific studies published since 2013 to draft the latest version of what has now become the established science on climate change, before coming together – virtually – for two weeks of final checks and negotiations.

Despite travel restrictions and national lockdowns that delayed the report's completion for several months, organisers say they pulled off the effort with no notable technical glitches to meet their revised deadline.

For many of the scientists, the effort came with a personal cost. "You put a lot of yourself in it," said ETH Zurich climate scientist Sonia Seneviratne, who had to skip a family holiday to help finish the report.

Completing the politically sensitive "Summary for Policymakers" section, which 195 governments must approve by consensus, presented a particular challenge. Each word of each sentence needed to be scrutinized and debated.

"We spent sometimes hours on a footnote," said co-chair Valerie Masson-Delmotte, a climate scientist at the University of Paris-Saclay who described work on the report as a "marathon."

But Masson-Delmotte also said the chance to work on pioneering climate research with so many scientists around the world was "one of the biggest joys of my professional life."