Positive tipping points must be triggered to solve climate crisis

With global warming on course to breach 1.5^oC, at least five Earth system tipping points are likely to be triggered -- and more could follow.

Once triggered, Earth system tipping points would have profound local and global impacts, including sea-level rise from major ice sheet melting, mass species extinction from dieback of the Amazon rainforest and disruption to weather patterns from a collapse of large-scale ocean circulation currents.

The new commentary -- published in One Earth by researchers from the Global Systems Institute at the University of Exeter -- says positive tipping points must be triggered to help reach the levels of decarbonisation required.

"One reason for hope is that many of the tipping thresholds that are likely to be crossed first are so-called slow tipping systems, which can be briefly exceeded without a commitment to tipping," said lead author Dr Paul Ritchie.

"However, rapid decarbonisation that minimises the distance of any overshoot and -- even more importantly -- limits the time spent beyond a threshold is critical for avoiding triggering climate tipping points."

Dr Jesse Abrams said: "One mechanism for achieving the rapid decarbonisation levels required is ironically through positive tipping points, moments when beneficial changes rapidly gain momentum."

The research team point to the sales seen in electric vehicles, particularly across Scandinavia, as evidence for the capability of human systems exhibiting positive tipping points.

Professor Tim Lenton added: "Under the correct enabling conditions, such as affordability, attractiveness and accessibility, Norway have managed to transition the market share of electric vehicles from under 10% to near 90% within a decade."