As governments haggle over the future of fossil fuels at the ongoing COP28 climate talks in Dubai, scientists have warned that the natural world is in the danger zone for tipping points that could provoke “catastrophic” effects including mass migration, conflict and failure of food crops. In a new report, more than 200 researchers found that five major natural systems are already at risk of crossing tipping points that would lead to abrupt or irreversible change, from the Greenland and West Antarctic ice sheets melting to warm-water coral reefs largely disappearing. Those risks are coming at the current 1.2 degrees Celsius of global warming above pre-industrial times, they said - well under the 1.5C limit set in the 2015 Paris Agreement.
More worrying, triggering one tipping point could spark others as well, “causing a domino effect of accelerating and unmanageable damage”, the report said. That could threaten economic, social and political breakdown that would hit the most vulnerable communities the hardest, it warned. “This is the ultimate red line in the sand that we need to avoid,” Johan Rockström, director of the Potsdam Institute for Climate Impact Research, told journalists, emphasising that the risk of crossing a range of tipping points becomes “high” at 1.5C of global warming.
Keeping global average temperatures below that internationally agreed limit requires wholesale rather than gradual change, said the climate scientist, who helped organise a major conference on tipping points last year. Rockstrom said it was already too late to avoid passing 1.5C but any overshoot needed to be swiftly brought back down by phasing out fossil fuels and cutting planet-heating emissions.
“There is no business-as-usual path left anymore,” said Tim Lenton, lead author of the report and head of climate change and earth system science at Britain’s University of Exeter. The report said the threat “demands an urgent response”. To that end, it also highlighted “positive tipping points” - such as exponential growth of renewable energies and electric vehicle use, and expansion of plant-based diets. Those “can create a powerful counter-effect, avoiding spiralling disaster”, it noted.
To keep people and the planet in the safe zone, the researchers recommended steps including phasing out fossil fuel emissions by 2050 and backing ecological restoration worldwide, while noting that deeper knowledge is needed on tipping points. Also needed are more finance and better ways to help people adapt to a heating climate and deal with the loss and damage that cannot be avoided, they said. Governments should try to identify tipping points relevant to their countries in the next round of national climate action plans due in 2025, they added.
To spur the urgent pace of change needed to avert negative tipping points and unlock positive ones, “we must have leaders with the power to stand up to lobbyists and vested interests and the status quo - and we don’t always have that,” Lenton told the Thomson Reuters Foundation in Dubai. The Intergovernmental Panel on Climate Change has said emissions must fall by 43% by 2030 from 2019 levels to have a fair chance of keeping global warming to 1.5C. Last Wednesday, US climate envoy John Kerry told journalists that meeting the 1.5C warming goal requires net-zero emissions by 2050, and achieving that requires “largely” phasing out fossil fuels in energy systems by mid-century, along with carbon capture for industrial sectors where it is hard to do that. The language used to describe the future of fossil fuels in a final agreement is the most contentious issue at COP28, set to conclude tomorrow (Tuesday).