Is the West Antarctic Ice Sheet Doomed?

I read an interesting article on the NBC News website that echoed my recent post regarding Carbon Dioxide and Climate Change (I’m sure all of us appreciate a bit of validation, especially when sitting way out on a limb and hanging on for dear life).

Since the authors of the original study base their report — published in Nature Climate Communications — on respected agencies (including the Woods Hole Oceanographic Institute, the British Antarctic Survey, the Department of Earth and Space at the University of Washington, and others), it is my opinion that their projections should be taken with more than a few grains of salt — certainly with more veracity that my missive. (BTW: Within a day, this report had spread to many, many other reputable new services. I do not list them all here, and will base my comments on the original NBC site.)

For a bit of background information from earlier posts, feel free to click here for an Introduction to Glaciers. You can also click here for an earlier post discussing the reality of glacial melt and its impact on sea level rise.

The main thrust of the study is that the effects of climate change on the earth’s oceans is going to have a direct impact on the glaciers, and the ice shelves that spread out from their edges when they enter the ocean. And while the loss of alpine glaciers will be a contributing factor (i.e. Norway, Alaska, British Columbia, Patagonia, and others), the biggest effect will logically derive from the biggest glaciers: Greenland and Antarctica.

They make their strongest case for the West Antarctica Ice Sheet, which they indicate has the greatest immediate potential to impact sea level and therefore the viability — or more appropriately the lack thereof — of urbanization near the beach.

The study doesn’t make specific sea level rise predictions, but researchers have estimated in the past that the total collapse of the West Antarctic Ice Sheet could contribute about 10 feet to overall sea level rise. Remember: this is a vertical measurement — the horizontal flooding inland from the modern-day coastlines could, and would, be much greater.

I encourage you to check out the NBC article (or any of the others that pretty much say the same things), but a few quotes to summarize the findings may be in order:

It appears we may have lost control of the west Antarctic ice shelf melting over the 21st century,” said Kaitlin Naughten, an ocean modeler with the British Antarctic Survey, who is the lead author of the new study. “West Antarctic ice shelf melting is one impact of climate change that we’re probably just going to have to adapt to, and that very likely means some amount of sea level rise we cannot avoid. Coastal communities will either have to build around or be abandoned.

Even if humans stopped all fossil fuel use today and shut off the faucet of greenhouse gas emissions, “it wouldn’t be an on-off switch” for the ice shelves, said Catherine Walker, a glaciologist at the Woods Hole Oceanographic Institute, a nonprofit research organization in Massachusetts, who studies Antarctica and was not involved in the study. “The processes already in motion would carry the current setting through over several decades.”

If we can plan ahead to reduce human suffering and save human lives, that’s better than closing our eyes when the ocean is on our doorstep.

Anyway, while I didn’t see any reference to the high specific heat of water as the overriding cause of the long-term problem, it sounds like this is what they are saying.

One observation I’d like to make before closing this one up for now: I hope they are right on their “centuries” time frame for the serious sea level rise, but… One of the things that we have seen repeatedly regarding the escalating climate issues is that it tends to move quicker — in some cases much quicker — than the projections.

This surely relates to the average global temperature and our promise to keep it to 1.5C° as per the Paris Accords (we have pretty much already blown past this one), and the raising of the ocean temperature — also moving up faster than originally predicted (or hoped).

Actually one more observation regarding sea level rise: sure, the additional water from the melting cryosphere will cause the amount of water in the ocean to increase, but there is another factor that will continue to impact sea level: the temperature of the water itself. This is a real double whammy: as the ocean temperature raises, it melts the ice from the bottom up (as well as top down due to a warmer atmosphere), but… warmer water takes up more space than colder water, so the ocean will (and already is) literally expanding due to this temperature increase. And, since the only way it can go is up, this will lead to flooding of the coastlines (I hear Poppy again). Not really a big deal yet (except during king tides during a storm), but this, too, will likely become a greater issue as the years and decades (and centuries) rush by.