The Greenland ice sheet, a colossal expanse of ice that holds a significant portion of the Earth's freshwater reserves, is losing mass at an alarming rate. A recent study warns that the ice sheet, nearly three times the size of Texas and covering about 656,000 square miles (1.7 million square kilometers), is inching toward a critical tipping point. This could occur by the turn of the next century if current trends persist. The loss of ice, driven by human-caused climate change, poses a dire threat to global sea levels and coastal communities worldwide.
The Greenland ice sheet, along with the Antarctic ice sheet, comprises more than 70% of Earth's freshwater reserves. However, it is currently shedding an estimated 33 million tons (30 million metric tons) of ice every hour. Between 2000 and 2019, Earth's glaciers lost an average of 294 billion tons (266 billion metric tons) of mass annually. Since 1994, the Greenland ice sheet alone has lost a staggering 6.9 trillion tons (6.3 trillion metric tons) of ice.
A 2021 study highlighted that Earth is losing enough ice each year to cover a frozen area the size of Lake Superior. This accelerating loss is pushing the Greenland ice sheet toward an irreversible tipping point. Once this point is reached, the ice sheet could potentially collapse into the ocean. Researchers predict that this tipping point will arrive when approximately 230 gigatons (253.5 billion tons) of ice is lost in a single year, marking a 60% decrease from its pre-industrial equilibrium.
The looming threat of rising global temperatures exacerbates the situation further. Just a 3.6 degrees Fahrenheit (2 degrees Celsius) increase in global temperatures could trigger a collapse of the Greenland ice sheet. If global temperatures rise by 6.12 degrees Fahrenheit (3.4 degrees Celsius) above pre-industrial levels, it could lead to the complete melting of the ice sheet. Such an event would result in catastrophic sea level rises, endangering billions living along the world's coastal areas.
The study emphasizes that the Greenland ice sheet's mass loss is accelerating due to climate change induced by human activities. To better understand when a tipping point might occur, researchers developed a climate model simulating the future surface mass balance of the ice sheet under various warming scenarios. This model estimates the snow buildup and loss due to melting, providing crucial insights into the potential timing of a tipping point.
