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Two minutes to midnight: How close are environmental ‘doom loops’?

With the Northern Hemisphere’s summer already seeing heatwaves, extreme forest fires and noxious air quality, red flags of ecological collapse are more visible than ever. 

people walking on sidewalk near green trees during sunset

By Monday 19th June, around 5million hectares of Canada had been burn in the country’s worst wildfires on record. That’s more than the cumulative total of 2016, 2019, 2020, and 2022’s warm weather months. 

It’s unclear what the long-term impact of this will be, not least given blazes have been growing more ferocious over the course of several years, wreaking much greater habitat destruction that risks pushing ecosystems past the point of recovery. The fallout in terms of air pollution and emissions is also worrying, with large parts of the United States being exposed to noxious fumes that have reached major urban areas including New York. 

This alone highlights how the impact of environmental events and disasters is rarely limited to the immediate vicinity, in turn accentuating the fact that the climate system is connected throughout the globe, and what happens in one location has a knock on effect elsewhere. Now, new computer modelling focused on so-called ‘doom loops’ – where a tipping point is reached in the world’s natural balance, trigging another – has sounded a particularly unsettling alarm bell. Simply put, widespread ecological collapse could be much closer to present day than we hope. 

Simon Willcock, Gregory S. Cooper, John Addy and John A. Dearing’s paper, Anthropocene ecosystems collapse much sooner with multiple faster and noisier drivers, was recently published on by Nature Sustainability. According to the modelling used, some systems could be 80% nearer collapse than previously understood. Running numbers more than 70,000 times for each ecosystem, adjusting for variables in the process, up to 15% of collapses were shown as most likely to occur from added stress factors and sudden, extreme events.

This was true even when the main stress level was kept at a constant. Sadly, the number of major climate-related events has been rising since 1980, and the proposed 1.5C limit on global temperature rise is expected to be broken imminently. This heightened level of warming, and the high probability of large-scale disasters occurring, are prime examples of the kind of added stress factors and extreme events the study points to. 

‘In the past two years, the world has come together around the climate and ecological crises through the UN Climate Change and Biodiversity Conferences. But we should remember that the causes of the crises are interlinked – that they have already collided – and that inaction over both may result in dire consequences,’ said Willcock.

‘Previous studies of ecological tipping points suggest significant social and economic costs from the second half of the 21st century onwards.  Our findings suggest the potential for these costs to occur much sooner,’ added co-author Professor John Dearing.

Highlighting the difference in this new research and preceding work, the Intergovernmental Panel On Climate Change has already estimated the Amazon’s tipping point will be reached before the end of this century. Willcock, Cooper, Addy and Dearing now believe this could be within the coming decades, as innate abilities to recover following drought and wildfires is damaged and reduced through deforestation and climate change. 

‘All four of the ecological systems we looked at showed the same overall outcomes,’ said co-author Dr Gregory Cooper. ‘This has potentially profound implications for our perception of future ecological risks. While it is not currently possible to predict how climate-induced tipping points and the effects of local human actions on ecosystems will connect, our findings show the potential for each to reinforce the other. Any increasing pressure on ecosystems will be exceedingly detrimental and could have dangerous consequences.’

You can read the full report here.

More on climate tipping points: 

Rapid sea heating could be evidence of ‘hidden climate risks’

27 feedback loops could accelerate climate crisis, warn scientists

Positive ‘tipping points’ offer hope for climate crisis

Climate scientists won’t know exactly how the crisis will unfold until it’s too late

Image: Thom Milkovic

 

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