‘Point of no return’ for Earth is getting nearer as our ‘hothouse planet’ boils
A team of scientists has warned we could be reaching a number of tipping points that might trigger runaway heating and a devastating and ‘disruptive’ future for humanity
There could be no way back if we’re not careful (Image: Getty Images)
Earth is teetering on the brink of a climate “point of no return” and scientists reckon we may be far closer than anyone thought. If global heating keeps rising, it could trip a series of climate tipping points that unleash a chain reaction. The end result would be a brutal “hothouse Earth” far beyond the 2-3C rise the planet is currently heading for.
That future would look nothing like the stable climate of the last 11,000 years, the conditions in which human civilisation grew and thrived. Researchers say the risk of crossing this irreversible threshold is not widely understood by the public or politicians.
“Crossing even some of the thresholds could commit the planet to a hothouse trajectory. Policymakers and the public remain largely unaware of the risks posed by what would effectively be a point-of-no-return transition,” said Wolf.
He added: “It’s likely that global temperatures are [already] as warm as, or warmer than, at any point in the last 125,000 years and that climate change is advancing faster than many scientists predicted.”
Carbon dioxide levels are also likely at their highest in at least two million years, according to the team. The study, published in the journal One Earth, pulls together the latest science on climate feedback loops and 16 so-called tipping elements.
These include the Greenland and Antarctic ice sheets, mountain glaciers, polar sea ice, permafrost and sub-Arctic forests, the Amazon rainforest and the Atlantic meridional overturning circulation (Amoc), a powerful ocean current system that helps regulate the planet’s climate.
Scientists say tipping could already be under way in Greenland and west Antarctica. Permafrost, mountain glaciers and the Amazon rainforest appear dangerously close, reports the Guardian.
“Research shows that several Earth system components may be closer to destabilising than once believed,” the researchers concluded. “While the exact risk is uncertain, it is clear that current climate [action] commitments are insufficient.”
Prof Tim Lenton, a climate tipping points expert at the University of Exeter, warned the risks are grave even without a full-blown hothouse scenario.
“We know we are running profound risks on the current climate trajectory, which we can’t rule out could turn into a trajectory towards a much less habitable state of the climate for us. However, we don’t need to be heading towards a hothouse Earth for there to be profound risks to humanity and our societies – these will already be upon us if we continue to 3C global warming.”
Professor William Ripple, of Oregon State University, who led the analysis, added: “The Amoc is already showing signs of weakening, and this could increase the risk of Amazon dieback. Carbon released by an Amazon dieback would further amplify global warming and interact with other feedback loops. We need to act quickly on our rapidly dwindling opportunities to prevent dangerous and unmanageable climate outcomes.”
Scientists first raised the alarm in 2018 about the possibility of a hothouse Earth, where temperatures stay well above a 4C rise for thousands of years, driving massive sea level rise that would drown coastal cities. At the time, they warned the “impacts of a hothouse Earth pathway on human societies would likely be massive, sometimes abrupt, and undoubtedly disruptive”.
We are already living with 1.3C of global heating. Extreme weather is killing people and destroying livelihoods across the globe. And scientists recently that at 3-4C, “the economy and society will cease to function as we know it”.
For the latest breaking news and stories from across the globe from the Daily Star, sign up for our newsletters.
