20 Feet Sea Level Rises… Won’t Happen Overnight

The migration of a climate meme from over-hyped press release to uninformed discussion in more mainstream outlets is a constant in the climate debate. Just 5 days after publication of the paper “Sea Level Rise Due to Polar Ice-Sheet Mass Loss During Past Warm Periods” comes a story loosely based on it in Market Business asking “Will 20 foot rise of sea water level engulf whole earth?

They are joined in this by Tech Times, ZME Science, Climate Progress (surprise!), and (I’m not kidding here) several hundred other news articles. They don’t answer the question, but I will. No. The ZME article even shows a picture of what Europe would look like after 20 feet of SLR. It is greatly changed. It is still there. We’re not ready for this fellow yet. noah-and-animals-39461-print I read a handful of these articles. They all use the same quote from Andrea Dutton. “It won’t happen overnight.” But they bury that in frightening language and give no estimate of when it might actually take place.

This is despite the widely publicized projection of the IPCC in AR5–that between 26 and 98 centimeters of sea level rise is predicted for 2100. The 2007 IPCC report expects melting of the Greenland ice sheet to occur over about a 1,000 year period, delaying much of the expected sea level rise for many centuries. I have seen estimates of 3,000 years for full meltdown of the Greenland ice caps if climate change continues unabated. Fully melting the vast Anatrctic ice cap will take much longer.

They also use the same term to describe this 20 feet of sea level rise–‘irreversible.’ That’s despite the fact that the study is based on prior periods of high sea levels–that were reversed. That’s, umm, why we have this ice around us today.

Point being that like the game of telephone, as a message filters through the various levels of the media, the factual content is not improved with each passage. We can surmise that there will be periods in our future when all the ice has melted. That’s because there have been periods in the past when it happened.

But scientists are not predicting in within 1,000 years. Or 2,000 years. Can human caused climate change bring that date nearer? Yes, many scientists think so and on balance I agree. But how much closer? Jury’s still out. More importantly, if and when that day arrives there will still be dry ground for us to walk on. Land mammals survived the previous ice-free periods–even polar bears. It will be hugely disruptive for our remote descendants and if something we can do will push that day into the even more remote future, we should do it. But saying ‘it won’t happen overnight’ is not a scientific statement. It is a cheap way of not saying ‘it won’t happen for millenia.’


5 responses to “20 Feet Sea Level Rises… Won’t Happen Overnight

  1. Sadly, the headline “Not much happening” rarely works as click-bait.

  2. Don’t forget that, excluding the green house gas problem, the earth orbital changes and the long term isostatic rebound are taking us into an ice age.

    I think the orbital changes are a well known phenomenon. But I’ve read very little about the isostatic rebound.

    Rebound happens when the ice load is removed and the continental land mass rises. I’ve read a little about rebound, and also worked my own equations to understand how it can behave, and it seems we have the northern portions of North America and Europe with a much higher elevation. The higher elevations alter the way the snow is preserved on the ground, change albedo and the way outgoing long wave radiation is trapped.

    So, at this time, we have three mules pulling us in different directions. Greenhouse gases towards warming, the orbit and rebound towards cooling, and the sun activity wildcard pulling who knows where.

  3. Realistic estimates for melting the Greenland icecaps are more like “never”.
    Nothing this icecap is doing, if one takes care to look at evidence based reports, suggests anything close to a dangerous situation is happening in Greenland. Instead we see a dynamic icecap centered around the huge center dominated by the convex shape of the island trapping the ice.
    I would suggest that this is common for the climate concerned: a policy based on radical changes and costs today. Typical for the climate obsessed policy litany the payoff is non-existent. To prevent a predicted change over 3000 years (and likely far, far longer) is as close to crazy as one can get and still be able to tie one’s own shoes.

  4. Oreskes and Conway’s pulp fiction “Collapse of Western Civilization” has Antarctica and Greenland causing respective 5 and 2 meter rises in sea level in 20 years (about a foot a year). I understand that it is currently rising at a foot a century.

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