What are climate tipping points?

There is growing evidence that the climate is rapidly approaching critical tipping points beyond which abrupt and/or irreversible changes could occur. A 2023 report identified at least 5 major climate tipping points that are already at risk of being crossed and 3 more that could be exceeded by 2030. The report underscores the urgent need for greenhouse gas mitigation to avoid triggering these tipping points and initiating catastrophic environmental changes.

What are climate tipping points?

Climate tipping points refer to critical thresholds in the climate system that, when exceeded, can cause abrupt and/or irreversible changes. For example, continued global warming could trigger the collapse of ice sheets or the large-scale dying off of coral reefs. These changes are driven by feedback loops that reinforce the initial perturbation even if the original cause is removed. Breaching one tipping point can also increase the risk of crossing others through interconnected Earth system processes.

Major identified tipping points

Tipping points fall into three main categories: cryosphere (ice and snow), ocean-atmosphere circulation, and biosphere (ecosystems). Major identified tipping points include:
– Collapse of Greenland and West Antarctic ice sheets
– Widespread permafrost thaw
– Death of warm water coral reefs
– Disruption of a key Atlantic ocean current
– Boreal forest dieback
– Loss of Arctic summer sea ice

Proximity to tipping point thresholds

The 2023 Global Tipping Points report determined that 5 tipping points are already at risk at current warming levels of 1.1°C above pre-industrial levels. These include the Greenland and West Antarctic ice sheets, permafrost thaw, coral reef die-off, and Atlantic ocean current disruption.

Three more tipping points become threatened if warming exceeds 1.5°C, including boreal forest loss. Tipping points pose a major risk between 2-4°C of warming, a range aligned with current national policies.

Avoiding tipping points

The only way to minimize tipping point risks is urgent and aggressive greenhouse gas reductions to limit warming below critical thresholds. However, current climate policies are inadequate to prevent some tipping points from being crossed, highlighting the urgent need for accelerated climate action. Even if emissions are rapidly reduced now, some tipping point impacts may still be unavoidable due to committed warming.

Month: Current Affairs - February, 2024