Irreversible Climate Damage if Warming Exceeds 1.5°C

The world’s climate is at a critical juncture, with uncertain outcomes. A new climate model indicates that exceeding the Paris Agreement’s primary target for global warming could trigger a chain of tipping points, making recovery extremely difficult, if not impossible.

On our current climate path, there’s up to a 45 percent chance of surpassing one of four critical tipping points by 2300.

These findings come at a pivotal moment in the climate crisis. Last year, every day saw temperatures exceed 1°C above pre-industrial levels, bringing us dangerously close to the Paris Agreement’s 1.5°C threshold.

Some experts believe that our actions in the coming years will determine whether we stay within this limit, while others argue that we’ve already surpassed it.

Study Explores Four Critical Tipping Points in Earth’s Climate System

The study, led by Tessa Möller and Annika Ernest Högner at the University of Potsdam, examines four potential tipping points: the collapse of the Atlantic Ocean’s major current system, the Amazon rainforest, the Greenland ice sheet, and the West Antarctic Ice Sheet.

Recent warnings suggest that the Atlantic Ocean current system might collapse by 2050, and Greenland’s ice sheet is perilously close to a tipping point. Additionally, the Amazon rainforest might already be contributing more to global warming than it mitigates, potentially shifting the climate system in devastating ways.

The likelihood of crossing just one of these critical thresholds is referred to as the ‘tipping risk.’

The study’s authors state, “We find that tipping risk by 2300 increases with every additional 0.1°C of overshoot above 1.5°C and accelerates significantly for peak warming above 2.0°C.”

Present Decisions Shape Future Climate

Although these projections focus on a distant future, our actions today will set the course. The findings emphasize the importance of adhering to the Paris Agreement and keeping warming well below 2°C, even if the 1.5°C target is exceeded.

If global temperatures temporarily surpass 1.5°C, we may reach a point of no return. One tipping point could trigger others like falling dominoes, and it’s uncertain whether these thresholds can be reversed or slowed.

Möller, Högner, and their team used a conceptual model that considers this complexity to assess tipping risks in the short term (by 2100), the medium term (by 2300), and the long term (after 50,000 years).

At the current pace of warming, models predict that by 2300, the tipping risk could reach 45 percent, and in the long term, it could nearly double to 76 percent. And that’s only considering four tipping points.

While the authors acknowledge there is “considerable uncertainty” in current climate models, it’s still vital for scientists to continue predicting the consequences of overshooting our climate targets.

The international research team explains that the transient nature of an overshoot might provide a brief window to counteract human emissions through rapid interventions and stabilize the ice sheets before tipping becomes irreversible.

Reaching net zero greenhouse gas emissions by 2100 will be “paramount to minimize tipping risk in the long term,” the team emphasizes. The stability of our planet’s climate system hangs in the balance.

Read the original article on: Science Alert

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