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Amidst Disasters Around the World, Top Scientists Declare Links Between Extreme Weather and Climate Change
31
December, 2015
Andy
Lee Robinson said
it all-too-well — “El Nino + Climate Change = El Diablo.”
And
as the Washington Post so cogently notes — the world is now
experiencing a rash of Freakish
Weather from the North Pole to South America.
It’s what appears to be happening as these two major record weather
makers fire off simultaneously. A
grim tally that includes the highest river levels ever seen in
Missouri,
the worst floods England has seen since the Middle Ages, the
first time the North Pole has seen significantly above freezing
temperatures during Winter in modern record keeping,
city and region-crippling droughts spanning Central and South
America, and seemingly everywhere, but especially in the North
Atlantic where Greenland melt outflow has backed up the Gulf Stream,
storms that seem to laugh in the face of our weather history.
(Extreme
weather on both sides of the North Atlantic on December 29, 2015. In
upper right of frame, the daisy chain of lows named Frank bears down
on Iceland and the UK. Meanwhile, a severe storm dumps flooding rains
over the Central US. Image source:LANCE-MODIS.)
“This isn’t the climate I grew up with. We didn’t see this kind of weather in the 20th century. It’s just a continuation of the crazy weather we’ve seen over the course of the 21st century so far.”
Attributing
Single Extreme Weather Events to Climate Change
But
Dr. Masters will be the first to tell you that it’s tough to
scientifically prove that any one storm or weather system was altered
by climate change. In essence, it’s like trying to prove that this
home-run or that shut-out was caused by a baseball player taking
steroids. We know that the steroids result in a changed performance
by the athlete, just as we know that climate change alters the
overall performance of weather. But it’s devilishly difficult for
scientists to pin down the exact climate change mechanisms going into
this or that monster storm or mega-drought. It doesn’t mean that
climate change or steroids aren’t at work, because they are. It’s
just hard to pin down exactly when.
It’s
this gray area that climate change deniers and fossil fuel backers
have exploited to generate doubt that climate change is happening at
all. They’ve hyper-focused on this storm or that drought, rather
than the larger extreme weather and temperature trend — which is
clearly changing and worsening. It’s almost as if a group of
baseball fans got together to defend the use of steroids in the sport
and placed the burden of proof on whether or not an individual home
run was caused by the stuff. A false analysis that puts both
scientists and those concerned about the environment into the
ridiculous position of having to prove the existence of climate
change in one storm or a single drought. The ludicrous assumption
being that, otherwise, climate change doesn’t exist at all.
But
merchant of doubters didn’t count on one thing — the advancement
of science.
For
truth be told, we are now starting to tease out a few of the direct
influences of climate change on extreme weather events. One
particularly powerful element being what is known as the
heat-moisture engine. It’s well known that temperature
differentials and rates of evaporation can have a significant
influence on weather. And climate change itself fundamentally alters
these aspects of weather by 1 — changing the rate of evaporation
and precipitation on a global basis and 2 — putting hot and cold
air and water masses in places where they’ve never been before.
(Sea
surface temperature anomalies in the North Atlantic are just going
bonkers. From the blazing hot back-up of the Gulf Stream off the US
East Coast to the freakish cool pool related to increasing glacial
melt just south of Greenland to the abnormally warm and ice-free
Barents, sea surface temperature patterns in the North Atlantic have
been consistently and radically changed by factors related to
human-caused climate change. It’s a fearsome engine of extreme
weather that’s only recently emerged. One that may as well have the
words ‘human-forced warming’ etched across it in bold script for
all to see. Image source: Earth
Nullschool.)
In both the Atlantic and Pacific, the unusually warm ocean surface is throwing extra moisture into the air… Storms over land can draw moisture from as far as 2,000 miles away, he said, so the warm ocean is likely influencing such events as the heavy rain in the Southeast, as well as the record number of strong hurricanes and typhoons that occurred this year in the Pacific basin, with devastating consequences for island nations like Vanuatu. “The warmth means there is more fuel for these weather systems to feed upon,” Dr. Trenberth said. “This is the sort of thing we will see more as we go decades into the future.”
North
Atlantic Bombs Going Off The Chats
But
it is in the North Atlantic that the influences of human-forced
climate change upon the weather are starting grow most starkly clear.
There the impact of El Nino is far less obvious. During a typical
strong El Nino year, storms tend to form more-so over Iceland. And
we’ve seen that. But in the past, El Nino years have also tended to
bring colder weather to Scandinavia as the Northern Hemisphere Jet
Stream strengthened and locked cold air into the higher Latitudes.
However, this year, as in recent years, the Barents Sea has been
freakishly warm. This region, which during the 20th Century featured
much more sea ice than today, is now mostly ice free. And this broad
section of open water vents heat into the atmosphere, warming
Scandinavia and providing a weakness in the Jet Stream for warm air
invasions of the Arctic.
This
week, the warm slot over the Barents provided the pathway for a daisy
chain of low pressure systems — ranging from the UK to Iceland to
the High Arctic — to pull above-freezing temperatures all the way
to the North Pole.
It was an unprecedented event and one far less likely to have been
strongly influenced by El Nino than by human-forced climate change.
Another
feature in the North Atlantic related to climate change is a cool
pool of water south of Greenland. This pool is generated by
increasing glacial melt outflows from the warming and thawing
mountains of ice covering that frozen isle. In juxtaposition to the
warming Barents, this cool pool creates what in weather terms is
called a dipole. A region of cold facing off against a region of hot.
Dipoles are notorious for their potential to generate extreme
weather. And the Barents/North Atlantic anomaly dipole is something
entirely new. A weather system that aims a more heavily moisture
laden Atlantic storm track directly at the United Kingdom. An island
nation that this year is sitting directly in the path of a northward
moving warm wind. A warm air and moisture flow that has all too
frequently embedded monster rainstorms never before seen in the
isles’ history.
Extreme
Storm Was 40 Percent More Likely Due to Climate Change
Myles
R. Allen, a Climate Scientist at the University of Oxford, finds
warnings by weather and climate experts that instances of extreme
weather would emerge due to human-forced warming are now made real:
“As scientists, it’s a little humbling that we’ve kind of been saying this for 20 years now, and it’s not until people notice daffodils coming out in December that they start to say, ‘Maybe they’re right.’ ”
Dr.
Allen was the lead of a cutting edge scientific study that, earlier
this month, used model runs to find that the
recent spate of record UK floods was made 40 percent more likely by
human-forced climate change.
The study was spurred by a storm that dropped 13 inches of rain on a
Northern England town in just 24 hours. It’s worth noting that a 40
percent increase in extreme weather potential isn’t just a little
nudge of the needle, it represents what in scientific terms is known
as a state change. In other words, if heating of the world’s
climate system has made extreme storms 40 percent more likely in your
country, then your climate is now nothing like it was before.
(It’s
not just daffodils blooming in England. All over the western world
flowers have been blooming out of season during the freakishly warm
weather of Winter 2015. Above, the iconic cherry blossom blooms in my
hometown of Gaithersburg, MD on December 31 of 2015. Photo credit:
Robertscribbler.)
After
the study, the UK was hit time-after-time-after-time by similar
record flooding rains. One being the same system that drove
temperatures at the North Pole to above freezing in Winter, flung
rains over Arctic sea ice during the depths of polar night,
and whose rains and winds again spurred raging
floodwaters in North England that destroyed a beloved 300-year-old
bridge.
This isn’t just one instance. What we’re looking at here is the
likelihood that England will continue to experience these kinds of
freak storms on-and-on until at least March and probably through to
April. And that’s just this year. For the pattern is so altered now
that England appears to be facing an age of storms the likes of which
it has never seen before.
The
Climatic Disruptions Have Now Begun
Today The
New York Times is
calling it Climate Chaos, The
Washington Post —
Freakish Weather.
But what we are really seeing is the start of the extreme climate
disruption experts and scientists have been warning us about all
along. A disruption resulting from a severe warming of the globe’s
atmosphere, oceans, and ice. One that some tried to deny was
happening at all but that is now, as likely as not, wreaking havok in
their own hometowns. Given the dismal state of affairs, one has to
honestly ask the question — why didn’t we listen? Why didn’t we
act early to stop this horrendous mess? And following this question,
an assertion — we would be insane to not work as hard as we can to
prevent this abysmal situation from further worsening.
Links:
Hat
Tip to Andy
Lee Robinson
Hat
Tip to TodaysGuestIs
Hat
Tip to Suzanne
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