“We argue that the intervention time left to prevent tipping could already have shrunk towards zero, whereas the reaction time to achieve net zero emissions is 30 years at best,” the authors said.
Active problem areas
Led by Timothy Lenton, professor of climate change and Earth system science at the University of Exeter, in southwest England, the team identified nine areas where they say tipping points are already underway.
The team claims that these events are interconnected and change in one will impact another, causing a worsening “cascade” of crises.
The researchers said early results from preliminary models suggest the climate is much more sensitive than first thought and that a global tipping point is possible.
“Research last year analyzed 30 types of regime shift spanning physical climate and ecological systems, from collapse of the West Antarctic ice sheet to a switch from rainforest to savanna,” they added. “This indicated that exceeding tipping points in one system can increase the risk of crossing them in others.”
Emissions, global warming
The idea of a climate tipping point is not new. The UN Intergovernmental Panel on Climate Change (IPCC) introduced the concept 20 years ago.
Back then, the UN suggested such “large-scale discontinuities” would only come about when global warming exceeded 5 degrees Celsius above pre-industrial levels.
But the authors say data from the two most recent IPCC reports in 2018 and September 2019, suggest tipping points can happen between 1 C and 2 C of warming.
The model highlighted the consequences of how the interactions between a variety of climate change factors, such as the loss or weakening of carbon sinks, forest dieback, ice retreat and increased bacteria respiration, could combine to form a feedback loop which accelerates climate change.
The authors acknowledge that there are limits to their understanding of climate tipping, and further investigation is needed. But they say the possible impact could be so huge and “irreversible” that “to err on the side of danger is not a responsible option.”
In other words, not acting is “too risky to bet against” in their view.
And time is of the essence.
Hope is not lost, however. Researchers say that mitigating greenhouse gas emissions could still slow down the accumulation of these climate impacts.
What is needed, they say, is urgent international action to cut emissions, slow sea level rise, and to keep warming to 1.5 C.
“A saving grace is that the rate at which damage accumulates from tipping — and hence the risk posed — could still be under our control to some extent,” they said.
“The stability and resilience of our planet is in peril. International action — not just words — must reflect this.”
Source : Nbcnewyork