Fixing climate change will cost four times as much if we delay, experts warn: ScienceAlert

New research highlights the difficult choice we face when it comes to climate change: solve the crisis now or spend much more money and resources solving the crisis in the future, after environmental tipping points have been passed.

A team from Pacific Northwest National Laboratory (PNNL) and Los Alamos National Laboratory (LANL) came up with the required numbers using several variations of a climate model and the sea ice loss scenario.

Tipping points refer to thresholds beyond which widespread, significant changes become inevitable, even if the drivers of those changes are removed. In this case, researchers considered when ice-free polar regions would become inevitable, even if we could somehow stop global warming.

“Either you bear the costs now, just before the threshold is exceeded, or you wait,” says mathematician Parvathi Kooloth from PNNL.

“And if you wait, the level of intervention required to return the climate system to its original state increases steeply.”

It makes sense that the longer climate change persists, the longer it will take to reverse. But here, the researchers wanted to specifically quantify the increased costs after the tipping point using their ocean ice loss scenario.

In this case, once the tipping point is reached, a quadrupling occurs quickly, the team found.

While the models showed that the steep rise in costs can be delayed – potentially giving us more time to reverse course and fully restore an ecosystem – once this “exceedance window” has passed, the costs of reversal rise even faster.

Not all consequences of tipping points can be reversed, the researchers warn. And while turning points can be overcome quickly, repairing the damage and heading back the other way typically takes much more time and effort.

“If we arrive in 2100 without sea ice, reducing our emissions to the levels we are emitting now in 2024, when we still have some ice left, may not be enough to bring the ice back,” he says Kooloth.

“We may need to reduce emissions much further, to levels before 2024 – this asymmetry is important for us as we choose our path forward.”

Although each tipping point is unique – and a mix of many different factors and influences – researchers believe they all share basic principles. The team is confident that the sea ice insights gained here can be compared to other scenarios, from dying coral reefs to disappearing rainforests.

There is positive news here too. Studies like these have the potential to help us better identify and predict upcoming tipping points. In theory, this should help us avoid them – although as a species we’re not particularly good at heeding scientists’ warnings.

“We now know a lot about the climate system,” says Kooloth. “But even now, we’re never really sure how far or close we are to a tipping point.”

“Could we one day use observable precursors for early warning? I hope we succeed.”

The research was published in npj climate and atmospheric science.