Rapid collapse of Antarctic glaciers could flood coastal cities by the end of this century.

From Ice Apocalypse to Mega-Thunderstorms, Continuing to Burn Fossil Fuels Makes the World Scary as all Hell

Robertscribbler,

24 November, 2017

So I’ve got to say I feel for Eric Holthaus.

Here’s a smart guy. Probably a few years younger than me. A meteorologist by degree and a climate journalist by trade. A guy with two kids that, as is clear from his twitter comments, mean all the world to him. And he’s finally gotten to that point in his study of climate change where he’s thrown his hands up and said — this stuff scares the crap out of me, can we please all just do something about it?

(The calving front of the Pine Island Glacier as seen by a NASA DC-8 aircraft. Image source:Commons.)

For him, as with any of us, the point of existential realization can come through overexposure to a wide range of worsening climate problems. Declining ocean health, rising extreme weather, how much faster we are warming the world up than during the worst hothouse extinction, can all weigh heavily on the heart and mind of any compassionate, feeling person who takes these subjects seriously enough to actually read the science. For Eric, the big deal, and it is a very, very big deal, was sea level rise.

Ice Apocalypse

Yesterday, Eric penned this seminal article on the issue of ice cliff stability as explored by glacier scientist Robert DeConto entitled Ice Apocalypse.

Ice cliff stability is a pretty technical term. One that may make the eyes of your typical reader gloss over. But when we consider that the glaciers of Greenland and Antarctica can be upwards of two miles high, then the question of whether or not the cliffs of those great ice mountains are stable may start to generate a flicker of warning. May conjure up a phantom of the titanic roar set off when such ice giants tumble away into the sea as has happened throughout the deep history of Earth whenever the world warmed up by a certain amount.

When I think of the words ice cliff stability, my mind’s eye pictures a vast wall of numbing white-blue stretching hundreds of feet high. It expands both left and right as far as I can see. And it looms over an endless warming ocean. Waiting for a colossal fall if just that right amount of extra heat is applied.

Ice is fragile. It’s not like stone. It doesn’t flex much. It doesn’t give much. And even minor stresses are enough to make it shatter. We see this with ice cubes in a cup of water at home. Put an ice cube into relatively warmer water, and that little 1×2 inch block will snap and crack. Now just compound that fragility. Set it on the massive scale of a mile-high glacier. Not too hard to image what can happen.

(2012 filming of massive calving event at Jakobshavn Glacier.)

It’s happened already at Jakobshavn Glacier in Greenland. The ocean warmed. The ice shelf protecting the glacier dissolved. And the front of the gigantic glacier fell like great, enormous, white dominoes. We’ve seen it happening in films like Chasing Ice. And we’ve struggled to grasp the enormous scale of it.

Our burning of fossil fuels did this.

Jakobshavn is, even now, contributing to a more rapid rate of global sea level rise. But the amount of ice held back by Jakobshavn is small when compared to the vast volumes kept in check by the Pine Island and Thwaites Glaciers of West Antarctica. What Robert DeConto did, and what has apparently scared Eric Holthaus so much, was apply a computer model based on observations of Jakobshavn ice sheet collapse to these larger Antarctic ice masses.

The DeConto study unearthed results that, indeed, looked apocalyptic. From Grist:

A wholesale collapse of Pine Island and Thwaites would set off a catastrophe. Giant icebergs would stream away from Antarctica like a parade of frozen soldiers. All over the world, high tides would creep higher, slowly burying every shoreline on the planet, flooding coastal cities and creating hundreds of millions of climate refugees.

All this could play out in a mere 20 to 50 years — much too quickly for humanity to adapt…

Instead of a three-foot increase in ocean levels by the end of the century, six feet was more likely, according to DeConto and Pollard’s findings. But if carbon emissions continue to track on something resembling a worst-case scenario, the full 11 feet of ice locked in West Antarctica might be freed up, their study showed.

The DeConto study is just one scientific exploration of what could happen in West Antarctica this Century. And, already, reassurances to a worried Eric Holthaus are forthcoming.

Chris Mooney‏Verified account @chriscmooney

1. Over at Grist, @EricHolthaus has mega-piece on Antarctica’s Thwaites and Pine Island glaciers. My take: He’s right these are very worrying glaciers (esp. Thwaites), but I’m not sure about some of the dire sea level rise scenarios in the article.

8:23 AM - 22 Nov 2017

But the problem with the DeConto study, as with any other form of serious climate risk, is that there are plausible scenarios in which terrible catastrophic events are possible even if their degree of likelihood is still somewhat debatable. And reasonable precaution would dictate that even if there were just a 10-20 percent chance of DeConto like events coming to pass, we would do everything we could to avoid them. The risk of this scenario emerging, however, is probably a bit higher. As numerous studies have identified the potential for 6, 8, or even 12 feet of sea level rise by as early as 2100.

The Future of Mega-Thunderstorms Looks Grim if We Continue to Burn Fossil Fuels

Eric’s appeals to his Twitter friends related to his article were touching to me in that I feel like I go through similar shocks with each passing week. And what should be a time of national thanksgiving even as more than half of Puerto Rico’s population is still in the dark 63 days after the climate change amplified blow of Hurricane Maria is no exception.

For a model study recently produced by Nature Climate Change and explored by Bob Henson at Weather Underground has found that the rate of rainfall in large thunderstorm clusters could increase by 80 percent this Century if fossil fuel burning proceeds along a business as usual pathway.

To put this in context, an 80 percent increase in the amount of rain that fell in the Ellicott City Flood in Maryland last year would have produced nearly ten inches of rain in an hour and a half.

(The rainfall intensity in large thunderstorm clusters was found to be greatly enhanced under worst case fossil fuel burning scenarios [RCP 8.5] according to a recent Nature Study. Image source: NCAR, Nature, and Weather Underground.)

As with ice cliff instability, we find ourselves faced with another scientific term in the new study — mesoscale convective systems (MCS). And to translate this term we can simply say that MCSs are gigantic clusters of thunderstorms. The study found that rainfall amounts in the largest of thunderstorm complexes were greatly enhanced as warming proceeded along a business as usual track.

From the Study author’s statement to Weather Underground:

“These new simulations of future MCS rainfall are concerning, because they show very large increases in the amount of rain that a given MCS is likely to produce. The MCSs that we would today consider to be ‘extreme’ in terms of precipitation would become more commonplace in the future. There are also some regions that currently don’t see a lot of MCS activity that might start seeing some of these heavily raining MCSs in the future.”

These increases are on top of already elevated rates of rainfall intensity we presently see today in destructive events that our infrastructure and disaster planning is clearly not prepared for (as seen during Harvey). So as we take the time to give thanks for the great bounty that many of us still have, perhaps we should also take the time to think of the things we can do to keep safe what we have worked so hard for and care so much about and to do our best to help those who are less fortunate. Who have already fallen casualty to a time of troubles.