15 To 20 Foot Sea Level Rise Possible Sooner Rather Than Later

September 13th, 2019 by Steve Hanley

A draft of a report from the Intergovernmental Panel on Climate Change says rising sea levels and warming waters are about to unleash “misery on a global scale.” The final report is scheduled to be published on September 25. It warns that ocean levels could rise by several feet before the end of this century.

But Richard Alley, a noted climate scientist with a specialty in glaciers and ice sheets, warns the IPCC prediction may be greatly understated. He foresees the possibility that sea levels will rise 15 to 20 feet within the lifetime of our children and grandchildren. Here’s a video of a Skype call he did with two other climate scientists last year.

So who is Richard Alley? He is professor of geosciences at Penn State and a member of the Earth and Environmental Sciences Institute. His expertise is in glaciology, ice sheet stability, ice core analysis, and erosion of ice sheets. He tells Jeff Goodell of Rolling Stone that as bad as we think climate change might be in the coming decades, the reality could be far worse. Within the lifetime of his students there’s some risk — small but not as small as we might hope — that the seas could rise as much as 15 to 20 feet.

If that happens, kiss goodbye virtually every major coastal city in the world. Miami, New Orleans, large parts of Boston and New York City and Silicon Valley, not to mention Shanghai, Jakarta, Ho Chi Min City, Lagos, Mumbai — all gone. ” I don’t mean ‘sunny day flooding’ where you get your feet wet on the way to the mall,” Goodell writes. “I mean these cities, and many more, become scuba diving sites.”

Why is Alley’s threat assessment greater than the people who are preparing reports for IPCC? Bureaucracy, mostly. They are written in collaboration with a large group of scientists and are often watered down by endless debate and consensus-building. In total there are 18 lead authors and 69 contributing authors on the chapter that considers sea-level rise. Also, by the time the final reports are written, the underlying data is often not the most current available.

Michael E. Mann, Alley’s colleague at Penn State, argues that most coastal areas are incapable of dealing effectively with even a 3 foot rise in ocean levels. “The US is not ready for a meter of sea level rise by 2100. Just look at what happened in the wake of Superstorm Sandy, Katrina, in Houston, or Puerto Rico,” he says.

The Western Antarctica Ice Sheet Is Key

What concerns Richard Alley most is the utter impossibility of predicting with any degree of certainty what will happen to ocean levels if large portions of the Western Antarctica ice sheet suddenly break off and fall into Southern Ocean.

“We don’t really know,” Alley told Goodell in an email. He says there are few constraints in physical data and current models that might put a speed limit on the collapse. It could come slowly or it might happen very, very quickly. “The most likely future as projected by the IPCC is well on the small change/small damage ‘good’ end of the possible futures, with potential for slightly better, slightly worse, and much worse, but without a balancing ‘much better.”

“I personally am not planning to tell people that I know what [amount of warming determines if] ice shelves will or won’t break off, leaving cliffs that will or won’t crumble rapidly,” Alley adds. “So, for now, I have to leave large, rapid changes within my error bars, and I believe I have a duty to tell people this.”

Alley points out that the best way to avoid this uncertainty of a possible ice shelf collapse is to keep climate warming below 1.5º Celsius or less. In existing climate models, West Antarctica remains fairly stable below that threshold. But given the world’s current burn rate of fossil fuels, and the massive industrial and political transformation required to keep temperatures below that threshold, Alley knows that’s unlikely.

Mark Jacobson Weighs In

Another noted climate scientist, Mark Z. Jacobson, professor of civil and environmental engineering and director of the Atmosphere/Energy Program at Stanford University, tells CleanTechnica in an e-mail, “We are finding every day that global warming and its impacts are happening faster and with more ferocity than many scientists had estimated.

“Given that the volume of ice on Earth represents about 230 feet of sea level, a loss of 15 to 20 feet in the next couple decades is conceivable if emissions and warming continue unabated. Fortunately, there is a way to slow down this loss, but it requires a massive worldwide effort to eliminate at least 80 percent of total world emissions by 2030 and 100 percent shortly after.

“As a first step, immediately eliminating black emissions will have the fastest impact. Black carbon, which is particulate matter coming from diesel and jet engines as well as from gas flares, kerosene burning, biomass burning, and biofuel burning, is the 2nd leading cause of global warming (responsible for about 20% of warming) but by far the strongest component of warming per unit mass. It also has the shortest atmospheric lifetime, so stopping its emissions has an almost immediate benefit to climate.”

How Much Will This All Cost?

What Alley, and Mann, and Jacobson are talking about is rapid decarbonization of civilization. Happy talk and half measures ain’t gonna get it done. And it is going to cost an ungodly amount of money to make the transition happen. The current alleged leader of the free world says boldly that the cost is way too high. But compared to what?

As Jeff Goodell writes, “There are not enough economists in the world to calculate the trillions of dollars worth of real estate that would be lost in a scenario like this. Nor are there enough social scientists to count the hundreds of millions of people who would be displaced. You think the world is a chaotic place now? Just wait.”

We don’t have to look any further than one of the United States’ closest neighbors — the Bahamas. After suffering catastrophic devastation during Hurricane Dorian just 2 weeks ago, the Trump administration is raving about the “bad people” in the Bahamas and denying them temporary protected status to come to the US while their country attempts to rebuild itself after the storm. America’s southern border is besieged by asylum seekers who are often motivated by the failure of crops in their home countries due to the ravages of climate change.

All over the world, refugees are treated as mad dogs bent on raping and pillaging any host country foolish enough to let them in. Rising sea levels could imperil hundreds of millions of people. Do we think there will be no costs associated with that degree of human misery and dislocation?

And in the final analysis, how much is a planet that is capable of sustaining human life worth? An ounce of prevention today could be worth a pound of cure tomorrow, but humans seem genetically incapable of comprehending the economic advantages of taking appropriate action before disaster strikes.

That may prove to be our fatal flaw and ultimately the cause of our extinction. If we won’t do it for ourselves and we won’t do it for our children, what hope is there that humanity will avoid making the Earth unfit for human habitation? The Earth will become just a lifeless orb drifting through time and space for millions of years until the next sentient beings evolve from the primordial ooze. That’s one hell of an epitaph for humanity, isn’t it?

Featured image: Screenshot from British Antarctic Survey video









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