- The U.S. is warming fast. But if you take a look at
global climate records, it sure does look like
temperature is decreasing, at least for the last eight years. When NOAA released their
new data in early 2023, it went viral. And even weathered viewers
commented that this is proof that climate change is finally
moving in a cooler direction. We'll unpack that in a bit, but first, let's talk
about long-term trends. - The global land and
ocean temperature for 2022 was 1.90 degrees Fahrenheit
above pre-industrial conditions. - But not everywhere on earth is warming at the same speed. And there are wide swings around the globe from extremely fast warming to one particularly scary area of cooling. According to a draft government report, the U.S. has warmed 68%
faster than the global average over the past 50 years. And that doesn't even include Alaska, which has warmed way faster. - Across the lower 48, the annual temperature has
increased at an average rate of about 0.16 degrees Fahrenheit
per decade since 1895. But that rate of increase
is 0.44 degrees Fahrenheit since 1980. - So in this episode,
we're gonna figure out why the average temperatures were dropping over the past eight years, find out which parts of the
globe are warming fastest, and at the end, we'll call up a resident of the fastest warming county in the U.S. to hear what it's like. Oh, and it turns out that
there's an area in the U.S. that hasn't been warming
at all, so stay tuned. Okay, first, what's up
with the dropping temps? - The earth is not cooling. So here's the thing. There can be year to year variability, that means those ups and
downs from year to year. - We all understand
this on a smaller scale when it comes to changing seasons, right? We know that nature doesn't
operate in straight lines. As spring turns into summer, the temperature doesn't rise
incrementally every day. It might be warm on April
1st, then snow on April 8th, but no one doubts that August will be hot. And we see this with climate change, too. Temperature pulses
higher, then levels off, then pulses again. But choose the right
eight years to analyze and you'll see a downward trend. 2016 was 1.19 degrees above
pre-industrial levels, and 2022 was only 1.07. For reference, the Paris Agreement aims to keep the global
average temperature rise between 1.5 and 2 degrees Celsius. Even inside that range, we may hit some very
disruptive tipping points, including the loss of coral reefs and abrupt permafrost thaw, but no one lives in an average. - Every continent in the world is warming, but the rate of change
of that warm can differ from place to place. - So where is warming fastest and where is warming the slowest? There are two big picture factors at play: latitude and oceans. First, high altitudes in the
far north are warming fastest largely because of sea ice. As temperatures rise, sea
ice melts exposing dark water that absorbs more solar radiation, which causes more warming, and the cycle continues. Now, the cycle won't continue forever. Once enough sea ice has melted, this Arctic amplification will slow down and the Arctic will warm
at a rate more similar to the rest of the globe. But for now, if you're farther north, you're probably warming fast. Second, water reflects
more of the sun's energy than land does, and it has
a far higher heat capacity. So it takes a lot more energy
to raise ocean temperatures than land temperatures. That means our large
continents are warming faster than the oceans, and guess what? That's where humans live. Put this together and you
get this generalization. Large land masses in the
north are warming fastest. Most of the earth's land
masses are in the mid-latitudes and northern hemisphere. So those regions are warming
faster than southern regions, but which continents
are warming the fastest? Europe is the fastest warming continent at 0.47 degrees Celsius of
warming per decade since 1980, and Asia comes in a close second. Globally, there are some
unusual hotspots as well. A mysterious pocket off
the coast of Uruguay and Argentina has warmed twice as fast as the global average, causing algae blooms and mass
die-offs of marine species. There also seems to be a similar hotspot in the North Atlantic along
the coast of Delaware to Maine. These hotspots seem to be largely driven by shifting ocean currents
that bring warmer water to unlikely places. Interestingly, some
places are warming slower for unexpected reasons. Parts of Antarctica have slowed warming in part because of the ozone hole, and India is warming less
than its surroundings, because of severe pollution
keeping out solar radiation. And that cool spot in the Arctic, that's caused likely by
Greenland's melting ice. So that brings us back to the U.S. Researchers at the University
of Massachusetts found that the lower 48 is expected to reach two degrees of
warming, 10 to 20 years before the globe as a whole. From previous episodes, we know that the Western
U.S. is getting drier, and it turns out
precipitation plays a big role in which regions are warming. Vegetation, trees, and moisture
can help mitigate warming, while drought can make it worse. - [Karin] But we are
seeing parts of the west and the northern tier warming faster than the rest of the country. And a lot of the driver for
this is that drought periods in the west are becoming more entrenched, and as regions that are
dry become more dry, that means there's less
moisture in the soil. And so, you'll actually
have higher temperatures during the day. We're talking parts of
the interior Rockies, portions of, you know, Oregon, California, as well as parts of the Northern
Tier, Minnesota, Montana. - [Maiya] We also know that
the northeast is warming faster than the U.S. average, and is expected to reach 3
degrees Celsius of warming when the globe as a whole reaches two. - Higher latitudes are warming faster. Winter is the fastest warming season for the northern hemisphere,
certainly for the U.S. - This means extreme
winter warming all the way from Montana to Maine. One reason for this is that snow pack is melting
earlier in the season. Fewer days of snow cover
means more sunlight that absorbs into the
ground warming the region. We'll take a look at the fastest
warming county in the U.S. at the end of the episode, but first, we wanted to know
where is warming the slowest? - [Karin] If you look from the Gulf Coast to about the mid-Mississippi Valley, so sort of that south central
portion of the lower 48, there's like virtually no
trend in warming or cooling across that 128 year period of record. - Some scientists believe the polar vortex can help explain this anomaly. The warming Arctic has
made the jet stream wavier, allowing cold polar winds
to escape to the southeast, creating a cooling effect in
the winter and spring months. Scientists have also
connected this warming hole to periodic thick clouds
and high soil moisture that help keep daytime temperatures down. And while there was no warming trend over the past 120 years, the past 40 years do show
temperatures beginning to rise. So we know climate change is
experienced pretty differently around the world, but it also
varies from year to year. And it turns out that a big reason for the variation comes
back to El Niño and La Niña. - In an El Niño year, the waters in the Eastern
equatorial Pacific are warmer than average, and in the La Niña year, they're cooler and that helps to drive
various weather systems across the globe. So we often use the metaphor
of like being on an escalator, and that escalator is going up. And during an El Niño year, it's like standing on your
tippy toes on the escalator and a La Niña is like crouching
down on the escalator. The overall direction is still up, but you're seeing year to year variances. And in fact, the last three years, we've been in a consistent La Niña, which would be sort of a cooling. And what we've seen is really
kind of the leveling off, but it's keeping pace, you know, in the top 10 and close to
top 5, each of those years. - So what about the future? - It is very likely that 2023 will end among the 10 warmest years on record. And if it does, then the 10 warmest years on record would have
been the last 10 years from 2014 all the way to 2023. If an El Niño were to
form at the end of 2023 in continuing to 2024, there is a high chance that
the year 2024 could rank among the warmest years on record. - And that has big consequences, especially for regions
that are warming fast, which brings us to the fastest
warming county in the U.S., North Slope Borough and Alaska
home to the native community of Borough now called Utqiagvik. Since 1980, it's warmed 0.72
degrees Celsius per decade, significantly outpacing
the rest of the U.S. We called Eben Hopson to learn a little more about
what it's like living there. He's 23, a subsistence hunter and fisher, and advocate for his community. His Iñupiat ancestors
have lived in the region for thousands of years with a
constantly changing climate, but the current rate of
change is unprecedented. - Living here in the Arctic, you know, hunting, fishing, whaling, trying to survive here in the Arctic and not really expecting that
change could come so quickly. It's scary because, one, hunting's gonna
be different this year; two, thinking about the future, the conditions that I
teach the future generation and will not be the same as
the conditions are today. - And there are concrete examples of what near four
degrees of warming means. - All of the houses
here on the arctic slope and they're built on stilts, maybe eight to 10 feet in
the ground in the permafrost. And once the permafrost
around those posts melt, then that house kind of shifts to one side and it's hard to open
doors, hard to open windows until you you correct the sinking pilot. - Eben does remember this
from his early childhood. - But it's more prevalent
now than it was then. - Traditionally, his community gets ready for the spring whale hunt in April when snow buntings arrive. But this important marker of the season seems to be changing. - Today is April 13. I haven't seen a snowbird yet. Once I see a snowbird, then that'll tell me the
the bowhead whales are here and they're ready to be harvested,
ready to feed the people. - He told us that the bird and whale timing just
seems to be out of sync, and whaling is getting less consistent. - I mean, yeah, there's beef, chicken,
and pork at the store, but that's not as healthy and nutritional as fresh, locally-sourced
bowhead whale muktuk and meat. - So what about where you live? Are parts of your life
changing in a warming climate? Is your your city warming
faster or slower than average? Let us know in the comments
and we'll see you next time. Our weather is changing from longer hotter heat waves
to more intense rainstorms to mega fires and multi-year droughts. The U.S. is experiencing the full range of impacts from climate change. Find out what people on
the front lines are doing to combat weirder weather
in Nova's latest episode, "Weathering the Future". The full episode is live on Nova's YouTube channel right now. Check it out at the
link in the description and tell them Weathered sent you.
