Associated Press

What to tell your skeptic friends.

The cold air pushing toward America’s heartland is of a duration and magnitude rarely seen since record-keeping began in the 1870s. In Minneapolis, forecasters warned that all-time wind chill records could be broken, with a stunning -65ºF predicted for Monday morning.

As the record-setting cold spreads across the US, brace yourself for this conversation:
 

Your friend: "Sure is cold outside, amirite? Minneapolis is as cold as Mars right now. Crazy, huh? So much for that whole global warming thing, eh?"

You: "Well…"

In fact, despite the trolling of Donald Trump and other climate change deniers, global warming is probably contributing to the record cold, as counter-intuitive as that may seem. The key factor is a feedback mechanism of climate change known as Arctic amplification. Here’s how to explain the nuts and bolts of it to your under-informed family and friends:

Snow and ice are disappearing from the Arctic region at unprecedented rates, leaving behind relatively warmer open water, which is much less reflective to incoming sunlight than ice. That, among other factors, is causing the northern polar region of our planet to warm at a faster rate than the rest of the northern hemisphere. (And, just to state the obvious, global warming describes a global trend toward warmer temperatures, which doesn’t preclude occasional cold-weather extremes.)

Since the difference in temperature between the Arctic and the mid-latitudes helps drive the jet stream (which, in turn, drives most US weather patterns), if that temperature difference decreases, it stands to reason that the jet stream’s winds will slow down. Why does this matter?

Well, atmospheric theory predicts that a slower jet stream will produce wavier and more sluggish weather patterns, in turn leading to more frequent extreme weather. And, turns out, that’s exactly what we’ve been seeing in recent years. Superstorm Sandy’s uncharacteristic left hook into the New Jersey coast in 2012 was one such example of an extremely anomalous jet stream blocking pattern.

When these exceptionally wavy jet stream patterns occur mid-winter, it’s a recipe for cold air to get sucked southwards. This week, that’s happening in spectacular fashion.

Climate scientist Jennifer A. Francis of Rutgers University explains this process in a short video (h/t Climate Progress):

This effect has already been measured with mid-level atmospheric winds in the northern hemisphere decreasing by around 10% since 1990. Not-so-coincidentally, that’s about the same time when Arctic sea ice extent really started to crash.

francis_gallery_sept_ice_550

The solid line is average west-to-east wind speeds midway up the atmosphere; the dashed line is Arctic sea ice extent.

Skeptical Science (the ‘Snopes’ of climate science) has a comprehensive explainer on Arctic amplification and the jet stream, for those that want to dig deeper on the subject. And, as a PSA, is a great-go to resource when situations like this arise.

This post originally appeared on Quartz. More from our partner site:

About the Author

Most Popular

  1. photo: a For Rent sign in a window in San Francisco.
    Coronavirus

    Do Landlords Deserve a Coronavirus Bailout, Too?

    Some renters and homeowners are getting financial assistance during the economic disruption from the coronavirus pandemic. What about landlords?

  2. photo: an empty street in NYC
    Environment

    What a Coronavirus Recovery Could Look Like

    Urban resilience expert Michael Berkowitz shares ideas about how U.S. cities can come back stronger from the social and economic disruption of coronavirus.

  3. Equity

    The Last Daycares Standing

    In places where most child cares and schools have closed, in-home family daycares that remain open aren’t seeing the demand  — or the support — they expected.

  4. Equity

    We'll Need To Reopen Our Cities. But Not Without Making Changes First.

    We must prepare for a protracted battle with coronavirus. But there are changes we can make now to prepare locked-down cities for what’s next.

  5. photo: An empty park in New Rochelle, a suburb of New York City hit by a spike in coronavirus cases.
    Coronavirus

    Are Suburbs Safer From Coronavirus? Probably Not.

    Urban density does play a role in disease transmission. But rural areas and suburban sprawl aren’t necessarily safer spaces to ride out the Covid-19 crisis.

×