Floods in New York, Drought in California: New Research Links Extreme Weather to Global Warming

The entire universe in blog form
Aug. 14 2014 8:00 AM

New Research Links Extreme Weather to Global Warming

453561078-police-officer-drives-past-flooded-cars-abandoned-on
Islip, New York, got slammed with 35+ cm of rain in less than a day on Aug. 13, 2014, causing widespread flooding. New research suggests global warming may be a root cause of extreme weather events like this.

Photo by Andrew Theodorakis/Getty Images

If you live in some parts of the Northeast United States,* you just experienced two months’ worth of summer rain falling in less than a single day.

Of course, if you do live in the swath of the country from Detroit to New York and down into the mid-Atlantic states, you hardly need me to tell you that. Look out the window. But what you might want to know is that the deluge you’re getting may be due to climate change.

Advertisement

Tying extreme weather to climate change is tricky. It’s not so much “this event was due to the Earth warming, which is disrupting the climate” as it is “statistically speaking, we’re seeing more extreme weather events, getting even more extreme over time”. Think of it as playing craps with ever-so-slightly loaded dice. You can’t be sure that snake eyes you threw was due to the dice being weighted, but over time you’ll see a lot more of them than you’d expect, statistically, from fair dice.

We’re throwing an awful lot of meteorological snake eyes lately.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

A paper just came out by a team of climatologists possibly linking global warming to these extreme weather events. It’s based on an idea that’s been around a while, but hadn't been verified. Now we’re seeing evidence for it.

The key to this is what’s called a “blocking pattern”, where a high-pressure system becomes immobile, squatting over a specific spot. Under the high-pressure spot, this can bring long, grueling heat waves that don’t go away for days or weeks. On the edges it can bring a deluge of rain, as moist air from the south is brought up to meet colder air coming down from the north. That’s what Detroit and New York just went through.

These blocking patterns are themselves associated with the jet stream, the constant flow of air about 10 kilometers above sea level at latitudes between 30° and 60°. Sometimes the flow weakens, and the winds can dip down into more southern latitudes. These meanders (sometimes mistakenly called the “polar vortex”) depend on a lot of factors, but the new research just published indicates they may be due to the Arctic warming up. The physics is complicated — fluid dynamics is amazingly subtle and complex — but the research indicates a warming Arctic can create and amplify the conditions that lead to jet stream excursions, and therefore blocking patterns.

Alaska heat wave
In 2013, a blocking pattern squatted over Alaska, causing record breaking heat for the largest state.

Photo by Jesse Allen and Jeff Schmatltz, using data from theLand Processes Distributed Active Archive Center(LPDAAC) and theLANCE/EOSDIS Rapid Response.

It was a blocking pattern that led to a phenomenal heat wave in Alaska in 2013, to the floods in the Northeast, and to the unbelievable rain we saw here in my home town of Boulder last year; we got over 30 cm in just a day or two. A normally quiet creek near my house became a raging torrent:

During the Alaska heat wave, I mentioned that there were some scientists wondering if this were tied to global warming and climate change (similar thoughts happened after the Boulder flood as well), and of course the usual suspects came in and raised the zombies of denial.

This new paper supports what I was saying. Again, we can’t always point to any one event and say “global warming caused (or amplified) this — though sometimes we can. But as our planet heats up, as ice in the Arctic, Antarctic, and Greenland slides away, as California continues to suffer its most apocalyptic drought on record, pointing a finger at such things will get easier and easier.

Tip o’ the brolly to The Guardian.

*Correction, Aug. 14, 2014 at 14:15 UTC: I originally wrote the Northeast U.S., but of course only some parts got the torrential rain, like Islip, New York. I apologize for using imprecise language there.

TODAY IN SLATE

Politics

The Democrats’ War at Home

How can the president’s party defend itself from the president’s foreign policy blunders?

Congress’ Public Shaming of the Secret Service Was Political Grandstanding at Its Best

Michigan’s Tradition of Football “Toughness” Needs to Go—Starting With Coach Hoke

A Plentiful, Renewable Resource That America Keeps Overlooking

Animal manure.

Windows 8 Was So Bad That Microsoft Will Skip Straight to Windows 10

Politics

Cringing. Ducking. Mumbling.

How GOP candidates react whenever someone brings up reproductive rights or gay marriage.

Building a Better Workplace

You Deserve a Pre-cation

The smartest job perk you’ve never heard of.

Hasbro Is Cracking Down on Scrabble Players Who Turn Its Official Word List Into Popular Apps

The Ludicrous Claims You’ll Hear at This Company’s “Egg Freezing Parties”

  News & Politics
Politics
Sept. 30 2014 9:33 PM Political Theater With a Purpose Darrell Issa’s public shaming of the head of the Secret Service was congressional grandstanding at its best.
  Business
Moneybox
Oct. 1 2014 8:34 AM Going Private To undertake a massively ambitious energy project, you don’t need the government anymore.
  Life
The Vault
Oct. 1 2014 10:49 AM James Meredith, Determined to Enroll at Ole Miss, Declares His Purpose in a 1961 Letter
  Double X
The XX Factor
Sept. 30 2014 12:34 PM Parents, Get Your Teenage Daughters the IUD
  Slate Plus
Behind the Scenes
Oct. 1 2014 10:54 AM “I Need a Pair of Pants That Won’t Bore Me to Death” Troy Patterson talks about looking sharp, flat-top fades, and being Slate’s Gentleman Scholar.
  Arts
Brow Beat
Oct. 1 2014 10:44 AM Everyone’s Favorite Bob’s Burgers Character Gets a Remix You Can Dance to
  Technology
Future Tense
Oct. 1 2014 10:27 AM 3,000 French Scientists Are Marching to Demand More Research Funding
  Health & Science
Bad Astronomy
Oct. 1 2014 7:30 AM Say Hello to Our Quasi-Moon, 2014 OL339
  Sports
Sports Nut
Sept. 30 2014 5:54 PM Goodbye, Tough Guy It’s time for Michigan to fire its toughness-obsessed coach, Brady Hoke.