Tipping point

The world’s largest ecosystems may alter drastically faster than previously thought, according to a recent study published in Nature Communications, shedding new light on the behavior of climate tipping points.

Real-life cases reveal a pattern: bigger ecosystems collapse at a faster rate than smaller ones. According to the findings, climate tipping points could happen in a matter of years or decades, not on the ecological timescale of hundreds, or even, thousands of years.

Observing this trend, the authors – stressing high levels of uncertainty – forecast that, after a tipping point is passed, the Amazon rainforest could disappear in under 50 years, while Caribbean coral reefs could vanish in 15 years.

“The Amazon could die before I do,” study co-author Simon Willcock, a senior lecturer at Bangor University, pondered upon seeing the results. “I had never sat down and thought it might be gone in my lifetime. It’s quite sobering.”

Over a decade ago, a group of scientists published a groundbreaking paper on climate tipping points, widely regarded as an unlikely scenario at the time. But with evidence mounting, many scientists have more recently sounded the alarm on melting ice caps and tropical rainforest dieback nearing permanent regime shifts. Today, some of these tipping points are very likely just around the corner, with the potential of triggering devastating global effects such as runaway global warming, extreme weather and food shortages.

Leading Amazon experts Carlos Nobre and Thomas Lovejoy, wrote a recent editorial warning that the “Amazon tipping point is here,” based on real-world observations of a drying atmosphere. “We’re on the edge of a cliff,” Nobre told Mongabay. The modeling carried out by Willcock and his colleagues gives us a clearer picture of what a tipping point of this scale may look like.

Domino effects – called “cascades” by scientists – occur at a quicker pace in systems where habitats and species are interconnected, which is more common in the earth’s large biomes. While this interrelatedness helps these larger systems build resilience, interconnectedness also amplifies collapse.

It works similar to logs in a fire, Willcock explains: one log gives you an hour of fire, but two logs together give you an hour and a half because properties change with the size. “Extra relationships and linkages through animals and plants affect how shock can pass through the system.”

Large coral reefs, tropical rainforests and the frozen poles are seen by many as permanent features of the planet. But fueled by widespread human-led destruction, we are edging closer to climate tipping points and the dire consequences that will follow.

Excerpted from: 'Studies Reveal Climate Tipping Points Could Be Here Much Sooner Than We Thought'.

Commondreams.org