(gentle guitar strumming) - Who doesn't like snow? It's beautiful, it's fun and it might even mean
a day off of school. But, in a series about
natural disasters and climate, (alarm beeps)
(car crashes) we definitely need to cover this one. That's because even a very
small amount of ice and snow can really ruin your day
if you're not ready for it. Now, you'd think that our
planet's warming climate would mean the end of winter,
and scientists used to agree, but then something really
unexpected happened. While warming temperatures do lead to milder winters, on average, many locations in the mid-latitudes started to experience
record snowfall events. Even with Arctic Sea ice
extent at record lows, Boston just experienced
its snowiest decade since record keeping began. In this episode, we're gonna explain how average temperatures can be warming while changes in the Arctic might actually be making winters
in some areas, more severe, at least for the time being. And as always, we'll talk to experts about how to prepare, no
matter where you live. (mellow music) (wind whistling) There's a cow right there, but
you can't see it (chuckles). This is just insane. This is literally the worst
I think I've ever seen it and the visibility is just horrendous. - Extreme cold is, by
far, he leading cause of weather-related deaths
in the U.S. each year. According to the CDC, around 1,300 people die each
year from cold exposure. And that doesn't even take into account the over 1,800 traffic fatalities from snow and ice on the roadways. So, even though snow is fun, winter weather is worth preparing for. For public health officials
and transportation managers, a silver lining of a warming climate seem to be milder winters
and hopefully, fewer deaths, but then something happened that surprised even the
most astute scientists. - Go back in the year 90s, the models that we used to try
to anticipate climate change were showing a decrease in snowfall. And there was a very famous
New York Times article, "The End of Snow?" how places like New York City
(chuckles) won't snow anymore. - And in much of the world,
that's exactly what happened. Snowpack in the West has
been declining for decades. Nearly every glacier on earth is receding. But then in the winter of 2011, a very confusing trend
began to take shape. The new year started out
with a historic storm and in the North Eastern U.S., the blizzards kept coming year after year. The most severe snow storms
are given a rating category from one through five. And looking at the
frequency of these storms can give us an idea of climate trends. - If you look at by decade, since 1958, there were eight or less per decade. Over the most recent decade, there've been 27 of these
disruptive snowstorms. So, more than a tripling of
any other previous decade. - It will become the snowiest
decade for the region. And within that decade, 2015
exceeded all predictions. It was Stephanie Pollack's
first year as secretary of the Massachusetts
Department of Transportation. - We had 110 inches in a single season which was the we've ever
had in Massachusetts. And it was also cold and it
didn't warm up in-between and so it didn't melt, and the piles just got higher and higher. - 110 inches is more than double the previous average annual
snowfall of 48 inches. And it's not just the Northeast. Winter storms are getting more
severe in the Great Lakes, Northern Europe and Central and East Asia. - It was really hard
to clear the sidewalks. And then the other big
issue was our transit system to the point where we had
to shut the system down. And so we had the people who
we now call essential workers, but we didn't even have that word in 2015, we were trying to run buses for them but we couldn't run the subways. And it took weeks to get back to the point where we could run the
entire transit system. I think of the winter of 2015, as one indication that
the climate is changing and we have to be prepared
to live in a different world. - If you're confused about
this, that makes sense. It's why most people use
terms like climate change or even global weirding,
rather than global warming. First, let's talk about what conditions you need
to get a big snow storm on the East Coast, like a
nor'easter or a bomb cyclone. - To get these big snow storms here in the Northeastern U.S., you really need a confluence of events. You need a northerly flow
to bring in the cold air, you need a southerly flow
to bring in the moisture, you need strong high pressure
blocking to the North to kinda lock it in along the coast. - To put it in the simplest way possible, air around an area of low
pressure spins counter-clockwise and air around an area of
high pressure spins clockwise. When these two meet along with
enough cold air and moisture, they work together like gears
to batter the East Coast. But historically, these
systems aren't extremely cold, just a few degrees below freezing. So you'd think that the
two degree Fahrenheit rise in global temperatures would make more of these
storms simply turn into rain, but that's not what we're seeing. Instead, there's been more snow and more outbreaks of cold
air dipping down into the U.S. Dr. Cohen told us that a leading theory to
explain the increase of cold air from the Arctic, has to do
with Arctic amplification. You might remember from
our hurricane episode, that the Arctic is warming much faster than the global average,
twice as fast, actually. That's because dark water
and land surfaces absorb more of the sun's energy
than white, reflective ice. So, as ice melts, more of
these dark surfaces are exposed which amplifies warming, and a quickly warming Arctic,
destabilizes the jet stream. The jet stream is a fast-moving,
high altitude wind current that forms where cold and warm air meet. The greater the temperature difference between these air masses, the stronger the jet stream becomes. But, when that difference decreases, the jet stream can slow
dramatically and dip further South. There's also a giant mass of swirling cold air high over the Arctic called the polar vortex. When everything's stable,
we don't really notice it. But, destabilize the jet stream, and the polar vortex
becomes wobbly like a top as its rotation slows. - Instead of just sitting
there spinning quietly on the top of the globe
over the Northern Pole, now it starts to meander,
starts to wander around. When you have these disruptions
of the polar vortex, feels like it's like a dam breaking and the cold air just rushes out into the lower latitudes
and mid-latitudes. You get more amplified flow and more opportunities for snowstorms. (vehicles humming) - None of this is new, but
it's happening more frequently. And a growing number of
scientists like Judah, believe our warming climate
is driving the process that provides Boston with
enough cold air and moisture to set snowfall records. ("Miro - Hina" by The New Dawn Collective) Boston is relatively well-prepared to deal with harsh winters and there are very few cold
exposure deaths each year, but these polar vortex
events can push cold and even snow into cities
that aren't accustomed to it, which is actually more dangerous. And in January of 2014, the polar vortex was a major catalyst in
the winter weather event that brought just 2.6
inches of snow to Atlanta, crippling one of the nation's
largest cities for days. Children were stuck at school,
interstates were clogged, thousands were stuck in
their cars for hours. One mother even gave birth
on the side of the highway. This was a true disaster, all because the lack
of timely preparation. But, who could blame them, right? The South just isn't accustomed to dealing with winter weather so it doesn't take much for
it to become disruptive. To get some tips on how to
stay safe in big snow events, we talked to Peter Murphy from the Oregon Department
of Transportation. - You can go from dry,
bare pavement to black ice in a matter of feet, here. And if you're not prepared for that, you really can end up
in a sideways situation and in some cases it can be fatal. (alarm beeps)
(car crashes) And so consciousness of the direction the vehicle's going in, the conditions that we're
driving in, is critical, whether you're in New York
City, whether you're in Atlanta, whether you're in San Diego
or in Portland, Oregon. Be ready with the right
equipment, the right gear. Just make sure your car is equipped with the right kind of tires. We like to know that you've done what you can to get a full tank of gas before you've headed out on the road. Make sure you have that
extra stopping distance between yourself and the
other car in front of you. - If you're traveling
during winter weather it makes sure to have food
and water in your car. It's also smart to prepare a kit that includes things like an ice scraper, a shovel, gloves, warm clothing,
a blanket or sleeping bag, a flashlight, chains for your tires and even a spare cell phone battery. - But by and large, we're a society that has learned how to stay in place. COVID has taught us many
things; that's one of them. So, it is always in our power to not go someplace. (plow blade scraping) - Extreme weather is more
than just a traffic problem. So I'm calling Dr. Stuart
Harris to chat with him about what he sees as
an emergency physician at Massachusetts General
Hospital in Boston. Hi, Dr. Harris. What are the most common things you see as an emergency doctor when
winter weather gets extreme? - So, you can think about cold injury in a number of different ways. One is if your whole body gets cold, what we call hypothermia. As you get a little bit colder, our brains just don't work very well and people can do crazy things, we call it paradoxical undressing. They can start taking off layers
that they desperately need, people become sluggish and then just aren't able to move. - [Maiya] Warning signs of hypothermia include shivering, exhaustion, confusion, fumbling hands, memory loss, slurred speech and drowsiness. Hypothermia is a medical emergency so take action quickly to get
warm and get medical help. - Other types of injury are
sometimes very superficial, what we call frostnip or even frostbite, where tissues actually start to freeze. - [Maiya] Signs of frostbite include white or greyish/yellow skin, skin that feels firm
or waxy, and numbness. The best way to warm up frostbitten skin is with warm water or with body heat, if
that's not available. - [Stuart] We see a lot of falls, people on black ice going down, breaking an ankle, breaking
a leg, breaking a wrist. - As our climate continues
to shift, I'm in Atlanta, so we're seeing a lot more of these extreme cold events
dip further down to the South. - Yeah.
- What can people do to best prepare themselves
for extreme cold weather? - So, you're exactly right,
as the climate changes, what you thought was normal in Atlanta, or Texas, or
Virginia, is not gonna be. It's critical that we're prepared,
the appropriate clothing, that you're being thoughtful
about how you travel, that you're adequately hydrated
and have access to food. These are things that we
need to be mindful of. - Lastly, make sure to check
out our upcoming episode on creating an emergency pantry for when extreme weather comes your way. Thanks for watching this
episode of "Weathered" and as always, make sure
to give this video a like and subscribe so you
never miss an episode. Before you go, you should check
out "When Disaster Strikes", a new three-part
documentary series from PBS that follows the aftermath
of natural disasters in Mozambique, Somalia, and the Bahamas. Each episode documents
the on-the-ground response as frontline workers race to save lives, restore order from chaos,
and turn despair into hope. "When Disaster Strikes",
pbs.org and the PBS video app. ("The Watering Hole" by
Ian Paul Livingstone) ("The Watering Hole" by Ian
Paul Livingstone continues)
2.6 inches shut down a city and sent it into chaos? That blows my mind. Snow isn’t that difficult to drive in.
It shocks me how many people don't understand global warming .
I try to explain the effects of decreasing differential pressure to my red state Iowans who try to use the colder winters to prove to me global warming is a hoax...I'm losing.
Industrial CO2 warming globe causing Arctic Amplification bifurcating meandering vortex .