Recently, we have been hearing about “zombie ice.” It sounds scary, but that is what the people reporting about it want you to understand. We should take a look to see what it really means.
Greenland has always had a lot of snow, and in normal years more has fallen than has melted, so it has built up. In fact, it has built up to be thousands of feet thick in places. New snow packs down older snow, and the farther down you go in it, the harder it gets. Not all that far down, it is just ice. When ice is thick enough, it is weighted down enough to form glaciers. The distinguishing feature of glaciers is that they flow, very slowly, toward lower elevations. Eventually, the ice makes it to the sea and breaks into icebergs.
Over the past few decades, Greenland has had more ice melting than builds up. The glaciers have been moving toward the sea, but they have been getting thinner. We already knew about that.
A recent study in Nature Climate Change shows that in some areas, there is a lot of ice that is not advancing toward the sea (https://go.nature.com/3e2Qlsv). Instead, it is simply melting in place, because it is not being fed by enough snowfall and it is not getting any contributions from glaciers. This ice will all eventually melt, though we do not know quite when. William Colgan, a glaciologist at the Geological Survey of Denmark and Greenland and a co-author of the study, told the Associated Press, “It’s dead ice. It’s just going to melt and disappear from the ice sheet. This ice has been consigned to the ocean, regardless of what climate (emissions) scenario we take now.”(https://bit.ly/3Ebv1vH)
We should understand that the terms “dead ice” and “zombie ice” do not appear in the report itself. I have no doubt that reporters took the comment about dead ice and invented the term zombie ice to get people’s attention.
Regardless of where the term came from, however, the idea that the ice melt should be regarded as scary is valid. The study says the sea level will rise by 27 cm, which is 10.7 inches, because the ice will melt, regardless of what action we might take to prevent it. This is in addition to what we already knew might come during the rest of this century, more than doubling what was expected from Greenland ice. The article “Sea Levels Are Rising Along the East Coast,” on page 1 of this issue of Green Energy Times should give the reader an idea of what this amount of sea-level rise might mean.
The short story is that it can lead to a lot of damage to homes, to investments, and to the environment. It will speed up loss of land at the ocean’s edge in many places, making some areas uninhabitable, and the people who live there will have to move to other parts of the country as climate refugees.
That includes some quite expensive buildings in some places, but it means that transportation and utilities would be threatened for other areas along the coast, rendering them uninhabitable even if they are not flooding. It also threatens such infrastructure as nuclear power plants and chemical factories along the coast with flooding. And it will turn some natural areas into places that are nothing like what they are today.
Sadly, this could have been stopped, if we had taken quick action in years gone by. But we did not. Nevertheless, we have to keep trying, because if we don’t, it will certainly get much worse.