Calendar year 2017 is sure over time to be remembered for a number of remarkable, even historic, developments.
Among those is likely to be the extreme storms which for many will have left an indelible scar: violent hurricanes Harvey and Irma ravaging Houston and Puerto Rico, raging wild fires again punishing vast areas of the American West, in particular California; historically warm atmospheric temperatures globally, and more. Much more.
And each shared a common thread – rising sea levels.
That’s the focus of this month’s Yale Climate Connections “This is Not Cool” video, produced and directed by the author of this post. The video includes the views of some of the most thoughtful and best qualified experts in the weather/climate change field.
“You expect to see more storms at the very high end” of the thermodynamic limit for wind speed as the climate continues to warm, says Kerry Emanuel, PhD, of MIT. “Indeed, the frequency of high-end events is going up.”
Jeffrey Kiehl, PhD, of the National Center for Atmospheric Research, NCAR, in Boulder, points to volumes of studies exploring responses of extreme storms to a warming planet and concludes that “these systems that form in the tropics can propagate up to the polar regions.”
2017 hurricanes ‘a different animal’ altogether
James Hansen, PhD, concludes that with further warming, which experts acknowledge is inevitable, changes in North Atlantic Ocean circulation could result in “superstorms” unlike any in human history. He points to enormous 1,000-ton boulders tossed by rising seas and powerful waves on the island of Eleuthera in the Bahamas as illustrative of the power of such superstorms.
Researcher Blair Tormey of the University of Western North Carolina University reports having found fossilized sediments pointing to the cause: very large waves reaching tens of meters above sea level. “In the sense of hurricanes as we define them today,” Tormey says, “they’d be a different animal.”
With a “business-as-usual” approach to continuing GHG emissions, Kiehl cautions, the likelihood of more and more violent storms is highly likely.
That squares with the evidence being evaluated by Andra Garner, PhD, and colleagues at Rutgers University. They have been examining threats of sea-level-enhanced storms in the New York City area. Based on modeling well into the future and with continued sea-level rise, “we see a pretty significant increase in flood risk” even as many of those storms may track further east of the coast than is common now.
Picture this, Garner says: the prospects that the 500-year-floods from past centuries could, with the boost from sea-level rise, become the projected five-year floods over just the next three decades.