Gizmodo - Jody Serrano
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A lake of meltwater forms on the Greenland ice sheet near Sermeq
Avangnardleq Glacier.
(Photo: Sean Gallup, Getty Images)
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It’s no secret that the
Arctic is in trouble. And while the
worrying
state of the ice
in the region has made numerous headlines this year, they’re just the latest
twists and turns in a long-term trend.
One of the best gauges for putting what’s happening in the region into
perspective is the National Oceanic and Atmospheric Administration’s
Arctic Report Card, a compilation of environmental observations and analyses that the agency has
been producing annually for 15 years.
It was released earlier this
month, providing an in-depth look at the Arctic’s struggles as the climate
crisis reshapes the region. But if you’re more of a visual person, NOAA made
these neat — although worrying — graphics to help get a handle on what’s
happened this past year and how it fits into the bigger picture.
Join us as we take a dive into a series of graphics that highlight key findings
of the Arctic Report Card, and explain why you should care about what happens up
there.
►Ice on Land Continues to Dwindle
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The Greenland ice sheet lost mass again in 2020, but not as much
as it did 2019. Adapted from the 2020 Arctic Report Card, this
graph tracks Greenland mass loss measured by NASA's GRACE
satellite missions since 2002. (Graphic: NOAA)
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If the ice that
blankets Greenland
completely melts away, global sea levels would rise by 24 feet (7 meters).
While it won’t all disappear overnight or even in the next few decades, recent
trends paint a very worrying picture. Since 2002, the Greenland ice sheet has
lost roughly 268 billion metric tons of ice per year on average.
The annual record for ice loss occurred in 2019, which saw 532 billion
metric tons vanish due to a staggering heat wave and
bizarrely sunny skies. The loss raised ocean levels by 0.01 inches (1.5 millimetres), per the
Arctic Report Card.
That seemingly small rise is both a reminder that the sea level has risen
roughly a foot (30 centimeters) since the start of the Industrial Revolution
and a harbinger of what’s to come. The rate of rise is on track to quicken
this century as the ice on Greenland, along with glaciers elsewhere, and the
massive Antarctic ice sheet continue to melt.
Sea level rise is already harming coastal infrastructure, and the impacts will
worsen in the future. But the melting ice sheet isn’t the only warning sign of
what’s happening as temperatures rise in the Arctic.
►The Arctic Is Losing a Startling Amount of Sea Ice in the Summer
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Arctic sea ice concentration on September 15, 2020 — the day of the
smallest extent of the year — compared to the median extent (gold
line) reached on this date in Septembers from 1981 to 2010.
(Graphic: NOAA)
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Though it doesn’t contribute to sea level rise since it’s already floating,
Arctic sea ice is yet another indicator of the massive changes afoot.
This year’s sea ice cover reached its
second-smallest summer minimum
on record, clocking in at just 1.44 million square miles (3.74 million square
kilometers). The
lowest ever minimum extent
to date during the satellite era, or 1.32 million square miles (3.41 million
kilometers), was recorded in 2012.
But this year’s annual summer minimum is just one startling aspect of a problem
that goes back decades and is in fact more impactful if you look at it with a
wider lens.
The graphic above highlights the dramatic reduction of sea ice extent in just a
few years. The gold line is the median ice extent for 1981-2010, in which half
of the years had smaller extents and half had larger.
Meanwhile, the light blue to white area represents the sea ice concentration on
Sept. 15 of this year, the day of the summer minimum extent.
According to the Arctic Report Card, the downward trend for the summer minimum
in 2020 is 13.1% per decade relative to the 1981-2010 average.
►In Fact, It Has Lost an Area of Summer Sea Ice Larger Than 40 Maines
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A graph of daily ice extent since 2005. Years 2005-2009 are light
purple, the record-low year 2012 is salmon, other years for
2010-2014 are light green, and years 2015-2019 are blue. The 2020
daily extent line is in black. (Graphic: NOAA)
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Another way to analyse Arctic ice is to think about the state of Maine. Yes, you
read that right. As you can see in the graph above, the downward trend for the
summer minimum extent is clear.
The 13.1% dip per decade relative to the 1981–2010 average tells some of the
story. Each year that averages out to about 32,000 square miles (82,700 square
kilometres) of ice lost. That’s roughly the size of Maine. So over the past four
decades of satellite records, we’ve lost 40 Maines-worth of ice.
You can also divide the satellite sea ice record into thirds, which still shows
that the average minimum extent for each third has been successively declining,
with an especially dramatic dip from 2007-2020.
From 1979-1992, the average minimum extent was 2.64 million square miles (6.85
million square kilometres); for 1993-2006, it was 2.37 million square miles
(6.13 million square kilometres); and for 2007-2020, it was 1.71 million square
miles (4.44 million square kilometres).
Though the rate of loss has slowed over the past 14 years, the Report Card notes
this “reflects a changed Arctic with consistently low extent throughout the
period;” the 14 lowest extents in the satellite era have all occurred in the
last 14 years.
►The Ice That Remains Is Younger
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The age of sea ice in the Arctic at winter maximum in 2000 (left,
week of March 18) and 2020 (right, week of March 21).
(Graphic: NOAA)
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It’s not just the extent of the
sea ice that has changed, it’s also the character. Arctic sea ice has gotten
dramatically younger. As NOAA explains, when it comes to ice, age refers to
thickness and durability.
Young ice
is thinner and more likely to melt in the summer.
Older ice — which is typically four years or older — is ice that survives
year-round and keeps thickening over time. Per the
National Snow and Ice Data Centre, old ice can grow to be between six and 25-feet (1.8 to 7.6 meters) thick.
As you can see in the graphic, older ice in the Arctic is a sliver of what it
once was. In 1985, 33% of ice in the Arctic was very old ice; in March 2020,
only 4.4% of the sea ice was old.
According to
NOAA, 20 to 30 years ago, the sea ice on the Arctic was dominated by old sea ice.
As time went by though, old ice drifted out of the Arctic through the Fram
Strait where it melted in the relatively warmer waters of the Atlantic.
This wasn’t a problem then, as new batches of old ice were created
in the Beaufort Gyre, which NOAA describes a “nursery” for young ice to grow
thicker and stronger as it drifts around for many years. Today, summers in the
southern branch of the Beaufort Gyre are often too warm for ice to survive, the
agency said.
To use a phrase from the
NSIDC, this “Benjamin Button ice” is an element in dangerous cycle, one in which
increasing air and ocean temperatures more easily destroy first-year ice and
weaken older ice.
If this cycle continues and older ice disappears
from the Arctic Ocean, the world may see ice-free summers in the Arctic as early
as 2030.
►The Northern High Latitudes Are More Flammable
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Rising surface temperatures have made fire fuels in Northern
Hemisphere high latitudes more flammable over the past 41 years.
This map shows the June trend (1979–2019) in the build-up index.
Brown indicates increasing flammability; purple indicates decreasing
flammability.
(Graphic: NOAA)
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We not only have the melting ice to worry about. We also have to stress about
the opposite: fire.
According to the Arctic Report Card, rising
surface temperatures in Northern Hemisphere high latitudes have made fire fuels
—
organic matter on the
ground or above the surface such as trees and peat that will ignite and burn —
more flammable over the past 41 years.
You can see this clearly in
the graphic above, which shows the buildup index trend in June from 1979-2019.
Brown indicates increasing flammability, while purple indicates decreasing
flammability.
The
buildup index
is an element of the Canadian Forest Fire Danger Rating System. It consists of a
numerical rating of fuel available to catch fire and considers surface
temperature, relative humidity, and 24-hour rainfall totals.
When the buildup index reaches certain levels, fires can burn more aggressively
and intensely. The graphic indicates that the widespread increase in the buildup
index in June at higher latitudes in both North America and Asia reflects that
conditions are becoming more favourable for fire growth.
Trends in
the availability of dry, flammable fuels for wildfire growth are consistent with
what we’ve seen on the ground in recent years as well as projections for the
next century.
Multiple climate scenarios project that there could be
up to a fourfold increase in burned area across the higher northern latitude
ecosystem by 2100.
►The Oceans Are Hot, Too
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Sea surface temperature trends in the Arctic from 1982–2020,
showing where waters are warming (red and orange) and where they are
cooling (blue). The grey line shows the median August sea ice
extent, and the white areas show the ice extent in August 2020.
(Graphic: NOAA)
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Considering all of the red and orange, you can probably guess what the graphic
above reflects: rising sea surface temperatures in the Arctic in August, which
is the peak of summer warmth.
The red and orange areas indicate
where waters are warming, while the blue areas show where they are cooling. The
white areas, meanwhile, reflect 2020’s sea ice extent, a dramatic reduction
compared to the median ice extent from 1981 to 2010, shown by the grey line.
According to Arctic Report Card, basin-wide sea surface temperatures
across the Arctic Ocean have been warming by 0.5 degrees Fahrenheit (0.3 degrees
Celsius) per decade.
The situation is more drastic in many of the
Arctic’s coastal areas, where August temperatures have been rising by as much as
1.8 degrees Fahrenheit (1 degree Celsius) per decade.
The Chukchi
Sea to the northwest of Alaska stands out for its especially strong warming as
do parts of Hudson Bay. One notable exception, however, is the northern Barents
Sea, which has experienced a cooling trend.
Ocean warming in the Arctic creates all sorts of problems for the region. More
heats leads to less sea ice, which in turn leads to more sunlight being absorbed
by the ocean, which consequently causes more ocean warming.
Warmer
oceans also delay fall freeze-up, affecting Indigenous peoples’ hunting and
fishing activities while also making coastal areas more vulnerable to damaging
waves during storms. It also reduces the amount of carbon dioxide the ocean
absorbs from the atmosphere.
►What Happens When You Lose Sea Ice
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(left) Sea ice concentration in July 2020 compared to the 2003–2019
average. Red areas had up to 100% less than their average sea ice,
while blue regions had up to 100% more ice than average.
(right)
Chlorophyll amounts — an indicator of ocean plant productivity — in
July 2020 as a per cent of the 2003–2019 average.
(Graphic: NOAA)
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The loss of summer sea ice has increased the productivity of microscopic ocean
plants in seven of the nine regions analysed by experts (the Sea of Okhotsk and
Bering Sea showed lower than average values, although both still showed a
positive increase over the 2003-2020 period).
These include
single-celled algae that live in sea ice, known as ice algae, and in the water
column, which are
phytoplankton. These algae are the base of the Arctic food chain and they rely on sunlight
to survive.
Scientists measure the activity of these plants by using
satellite-based observations of
chlorophyll, the photosynthetic green pigment phytoplankton use to capture sunlight and
then turn it into chemical energy, as a proxy for phytoplankton productivity.
The graphic above from shows the connection between sea ice concentration and
chlorophyll concentration. The key to understanding it is the following:
Below-average sea ice generally correlates with above-average chlorophyll.
Scientists
have found
that the early retreat of sea ice generally drives up primary productivity, the
rate at which marine algae dissolve inorganic carbon into organic material,
because it opens up the oceans to sunlight sooner.
But more plants might not necessarily be a good thing. Changes that are helpful
for one species can be harmful to others.
Research suggests, for
example, that the increase in plant production has contributed to an increase in
the bowhead whale population in the Pacific Arctic.
At the same
time, however, algae species that produce deadly neurotoxins are spreading
poleward, per the Arctic Report Card.
The defining message of the Arctic Report Card is that what once was is no more.
If we don’t drawdown emissions, those changes could occur even
faster and put even more pressure on the ecosystems and people who call the
fragile region home.
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