Climate tipping points: The Arctic is a Bellwether for Irreversible Change
“The Arctic is iconic for maintaining year-round ice and snow, but in the last decade, it has begun to transition to wetlands and open ocean. Emblematic of this change, in July 2020, the last intact ice shelf in the Canadian Arctic fell into the sea. Since first analyzed in 1902, the Milne ice sheet already lost 43 percent of its previous mass. Canada’s Ellesmere Island ice caps were also lost in the summer of 2020, as the ice deposited during the Little Ice Age (1600 to 1850) melted completely. Glacier melt, thawing permafrost and wetland expansion create a new landscape, changing ecosystems as well as altering the global atmosphere and ocean circulation.”
“The term “tipping point” is often applied to a moment of critical change in human history. In ecology, tipping points describe small changes that, over time, force an irreversible change. Yearly lows of sea ice and a startling increase in permafrost thaw in a warming climate signal that the tipping point has already been crossed. We have already lost the frozen Arctic.”
Small tipping points expand through ecosystems
“As ice and snow are lost, the warming climate makes it difficult to recover. Sea ice that is only a few months old covers gaps in the Arctic Ocean, with yearly loss of old ice greater than the annual gain. In 2019, the National Oceanic and Atmospheric Administration (NOAA) reported that just 1 percent of the Arctic Ocean ice older than four years old remained. A warming atmosphere and sea prevent ice growth, leading to an ice-free Arctic Ocean.”
Climate tipping points: The Arctic is a bellwether for irreversible change
…click on the above link to read the rest of the article…
