As reported by CNN, satellite images show a recent breakup of two shelves. Although these breakups contribute little to sea-level rise because most of their ice lays atop the water’s surface, they hold back the advance of the glaciers to the sea. The latter will significantly contribute to sea-level rise and reduce sea salinity levels.
About 80 square kilometers of the Milne Ice Shelf broke away from the northern coast of Ellesmere Island on July 30 and 31, as shown in satellite images. Ellesmere Island is located off the northwest coast of Greenland and is part of Canada’s Nunavut Territory. Although the calving of ice shelves contribute little to sea-level rise because they are in the water before they break apart, they act as dams by preventing glacial ice from advancing to the sea. Consequently, their break-ups will contribute to future sea-levl rise. In the meantime, the fresh water they release reduces ocean salinity, thus affecting marine life. Floating ice shelves further break-up and pose a risk to maritime shipping.
When most of us hear of polar warming it’s often about sea-level rise. True enough. However, Arctic warming is more problematic than Antarctica warming in terms of geopolitical conflict as China, Russia, Canada, and the U.S. vie for control of the newly opening waters. This is just one way in which climate change contributes to national conflicts.
Common to both Polar Regions, climate change also threatens wildlife–polar bears could be headed for extinction because the ice flows they depend on for catching seals and fish are disappearing. Penguins are at risk due to changes in their food supplies. These changes, along with rising sea-level, threaten the coastal villages of northern peoples.
We hear that the Polar Regions are warming at a faster rate than the equatorial and temperate regions. Why might this be? According to NASA’s Patrick Taylor, the seasonality of the polar warming is largely a result of energy in the atmosphere that is being transported to the poles through large weather systems. He said, “The total warming at the poles is due to changes in clouds, water vapor, surface reflection of sunlight and atmospheric temperature. But there is greater warming in the winter than in the summer and that is caused by energy transport.”
As the tundra starts to defrost and the oceans warm, methane (having about 25 times the greenhouse effect as carbon dioxide) is released. The summer of 2019 saw a ring of tundra files around the Arctic Circle land masses, further releasing more carbon dioxide into the atmosphere.
Though we cannot say with scientific certainty, we might already have reached a tipping point, meaning that even if our fossil emissions were reduced to zero by 2050, the then levels of carbon dioxide and methane in the atmosphere along with the continued release of carbon dioxide and methane from wildfires, warming tundra and oceans, and volcanoes would continue to heat the planet. See what’s happening to Greenland’s ice.
You can read the entire 2019 Arctic Report Card here.