The Intergovernmental Panel on Climate Change (IPCC) has warned that surpassing 2 degrees celsius of warming could have catastrophic consequences and that we need to keep global warming to 1.5 degrees celsius.
Increased warming could lead to climate tipping points. A tipping point is the point at which small changes become substantial enough to cause a larger, more critical change that can be abrupt, irreversible and lead to cascading effects. Recent IPCC assessments suggest that tipping points could be reached between 1 degree celsius and 2 degrees celsius of warming.
The Greenland ice sheet holds enough water to raise global sea levels by over 20 feet and its melting is accelerating. Most of the melting occurs on the ice surface because of warming temperatures, but as the height of the ice sheet declines, the surface is exposed to warming air at lower altitudes which further speeds melting.
The West Antarctic Ice Sheet (WAIS) is vulnerable to collapse because it rests on bedrock below sea level and is affected by the oceans’ warming. Antarctica as a whole contains enough ice to raise global sea levels by over 200 feet.
A recent study of the WAIS, the Greenland ice sheet, the Atlantic Meridional Overturning Circulation (AMOC), the El Nino Southern Oscillation (ENSO) and the Amazon rainforest tipping points found that they could interact with one another before temperature reach 2 degrees Celsius. This interaction would enable tipping to occur at lower thresholds than previously thought. The analysis found that a cascade could potentially begin with the melting of the ice sheets because their critical thresholds are lower. Scientists say that the limits of computing power make it impossible to represent each climate system’s tipping point or their interactions exactly.