A draft report from the world's peak body on climate change, leaked to a global news agency, has sparked concern - but the dire warnings the report details shouldn't come as a surprise, experts say.
The draft report from the Intergovernmental Panel on Climate Change (IPCC) was obtained by Agence France-Presse (AFP), a global news agency headquartered in Paris.
The draft reportedly describes how climate change will "fundamentally reshape life on Earth in coming decades, even if humans can tame planet-warming greenhouse gas emissions" with projections on food supplies, water scarcity, extinction rates, migration, infectious diseases and extreme weather events.
However, "the forthcoming IPCC report is not surprising for anyone paying attention to the climate science," said David Schlosberg, a professor of Environmental Politics at the University of Sydney, Australia, when asked about the leak.
"There is a well-known need for much more investment in substantive and inclusive adaptation planning to address existing community threats from heat, fire, and sea level rise," Schlosberg said.
"The more we ignore what's coming, the worse the impacts will be," he added.
But in true scientific fashion, the report authors are quick to add this is not the final word.
"It is a very preliminary and partial version of a volume of the report, which dates from November 2020," said François Gemenne, one of the report's lead authors and a researcher exploring environmental migration and displacement at the University of Liège, Belgium.
"This version does not take into account the thousands of comments received, nor especially the sections that are being written at the moment," Gemenne said in another tweet.
Acknowledging that the report is a work in progress, it still sends a clear message about the direction we are fast heading – towards tipping points in the climate system.
Tipping points are climate thresholds that once crossed, could trigger and amplify cascading impacts across the planet, with one ecosystem collapsing after another.
Examples include the irreversible melting of the Greenland ice sheet, which contains enough ice to raise global sea levels by seven metres, or the dieback of the Amazon rainforest, which would release unthinkable amounts of CO2 into an already overloaded system.
Warnings about tipping points are nothing new; climate scientists have been ringing the alarm bells for a decade now that our planet is hurtling towards critical thresholds.
According to AFP, however, the leaked report escalates that to at least a dozen potential tipping points beyond which the world's ecosystems would start collapsing.
#EXCLUSIVE Climate change will fundamentally reshape life on Earth in coming decades, even if humans can tame planet-warming greenhouse gas emissions, says a landmark draft report from UN's climate science advisors obtained by @AFP https://t.co/Q4ytmReVky pic.twitter.com/gry8gRPjsF— AFP News Agency (@AFP) June 23, 2021
With the draft report – which will be the IPCC's Sixth Assessment Report – the authors numbering in the hundreds also appear to be gearing up to issue some of their strongest warnings to date.
"Life on Earth can recover from a drastic climate shift by evolving into new species and creating new ecosystems," the draft reportedly says. "Humans cannot."
Although the exact wording of the final report will most likely change, what we can appreciate for now is that the Sixth Assessment Report from the IPCC could, most notably, be a mark of just how far climate science has progressed since the IPCC published its first report in 1990.
Past reports have tended to use cautious language that erred on the conservative side, hop-stepping around the uncertainty of climate models and their projections. Tipping points have been particularly difficult to quantify, in their timing and magnitude, but the sensitivity of climate projections is steadily improving.
"The exact timing of tipping points and the links between them is not well understood by scientists, so they have been under-reported in past IPCC assessments," Simon Lewis, a professor of global change science at University College London, told The Guardian.
"The blunter language from the IPCC this time is welcome, as people need to know what is at stake if society does not take action to immediately slash carbon emissions."
Other experts, such as Paul Read at Monash University in Melbourne, have suggested that actually, we already have the evidence we need to motivate climate action.
Climate models "have long suggested a bleak future by 2080 and 2100 that exceeds the safe limit for climate change [1.5°C of warming] set by the Paris Agreement – by doubling it," said Read, a psychologist focusing on global sustainability, natural disasters, and intergenerational equity.
Susan Park, a professor of global governance at the University of Sydney, had a similar message.
"The report reinforces our urgent need to act now" and "highlights the scientific research done globally on how climate change is fundamentally altering the life systems of our planet, with increasingly dire consequences for humanity", she said.
Some scientists declined to comment on the draft report, out of respect for the ongoing work and review process, but stressed the consequences of inaction all the same.
"In general, climate tipping points are extremely concerning," said paleoclimatologist Helen McGregor from the University of Wollongong, Australia.
"The message here is that there really are dire and costly consequences of increasing CO2 levels in the atmosphere. It is in all of our best interests to reduce emissions as soon as we possibly can."
The IPCC said in a statement that it does not comment on the contents of draft reports while work is still ongoing. It also noted that approval of the final report is anticipated in February 2022.
So perhaps the question we need to be asking ourselves is what can be done between now and then? Scientists have said that disastrous tipping points could be reversed – if we act fast.
As Tim Lenton and his colleagues wrote in 2019: "The stability and resilience of our planet is in peril. International action - not just words - must reflect this."