The issue of ocean acidification gained some traction this week
in the U.S. House of Representatives, where bipartisan support led
to the approval of four bills designed to bring new ideas into the
battle to save sea life from corrosive waters.
If passed by the Senate, the legislation would allow federal
agencies to set up competitions and offer prize money for the best
ideas for reducing ocean acidification, adapting to ongoing changes
or solving difficult research problems. The bills also foster
discussions about climate change by bringing more people to the
table while providing increased attention to the deadly conditions
that are developing along the coasts and in estuaries, such as
Puget Sound.
U.S. Rep. Derek
Kilmer
“We know that changing ocean chemistry threatens entire
livelihoods and industries in our state, said U.S. Rep. Derek
Kilmer, D-Gig Harbor, in a
press release. “There are generations of folks in our coastal
communities who have worked in fishing and shellfish growing — but
that’s endangered if we don’t maintain a healthy Pacific
Ocean.”
Later in this blog post, I will reflect on other
Kilmer-related issues, including the so-called Puget Sound Day on
the Hill.
In a phone conversation, Rep. Kilmer told me that he was
encouraged with the widespread support for a bill that he sponsored
called the Ocean
Acidification Innovation Act of 2019 (HR 1921), which passed
the House on a 395-22 vote. The bill would allow federal agencies
to sponsor competitions and offer prize money for the best ideas.
Money would come out of existing funds that agencies use for
related purposes. The bill was co-sponsored by Northwest Reps.
Jaime Herrera Beutler, R-Battle Ground, along with Rep. Suzanne
Bonamici, an Oregon Democrat, and Rep. Don Young, an Alaskan
Republican. Five representatives from coastal areas in other parts
of the country added their names to the bill.
“There is a legitimate problem, and people are beginning to see
the impacts of the changing ocean chemistry,” Derek said. “This
should a bipartisan issue.”
A new worldwide map of sea level rise, plotted with precision
satellite instruments, shows that the Earth’s oceans are rising
faster with no end in sight.
Sea levels have gone up an average of 3 inches since 1992, with
some locations rising as much as 9 inches. Meanwhile, some limited
areas — including the West Coast — have experienced declining sea
levels for various reasons.
Sea level change over 22 years.
(Click to enlarge) // Map: NASA
Two years ago, climatologists released an international
consensus, which predicted a sea-level rise of between 1 and 3 feet
by the end of this century. It was a conservative estimate, and new
evidence suggests that ocean waters are likely to meet or exceed
the top of that range, possibly going much higher, according to
four leading researchers speaking at a news conference
yesterday.
The implications are huge and growing more important all the
time. At a minimum, waterfront property owners and shoreline
planners need to begin taking this into consideration. It doesn’t
make sense to build close to the shoreline if extreme high tides
will bring seawater to one’s doorstep.
If we hope to avoid local extinctions of key intertidal species,
we must start thinking about how high the waters will be in 50 to
100 years.
For clues to the future, we can watch Florida, where vast areas
stand at low elevations. Even now, during high tides, Miami is
beginning to see regular flooding in areas that never got wet
before. This is the future of low-lying areas in Puget Sound, such
as estuaries. In the Pacific ocean, the threat of inundating
complete islands is becoming very real.
Along the West Coast, sea levels have actually declined over the
past 20 years, largely because of the cooling effect of the Pacific
Decadal Oscillation, a warming/cooling cycle that can remain in one
phase for decades. The cycle appears to be shifting, with the
likely effect that sea levels on the West Coast will soon rise as
fast or faster than the worldwide average, according to Josh
Willis, an oceanographer at NASA’s Jet Propulsion Laboratory in
Pasadena, Calif.
Global sea level has been
measured accurately and continuously by satellites since 1993.
Graphic: Steve Nerem, University of
Colorado
The cause of sea level rise is attributed to three factors.
Scientists estimate that roughly one-third of the rise is caused by
thermal expansion of ocean waters, which absorb much of the energy
from global warming. Another third comes from the melting of the
massive Greenland and Antarctic ice sheets. The remaining third
comes from the melting of mountain glaciers throughout the world.
Researchers at yesterday’s news conference said they expect the
melting to accelerate.
Measuring the change in sea-level rise has become possible
thanks to advanced technology built into altimeters carried aboard
satellites. The instruments can distinguish changes in elevation as
small as one part in 100 million.
“The instruments are so sensitive that if they were mounted on a
commercial jetliner flying at 40,000 feet, they could detect the
bump caused by a dime lying flat on the ground,” said Michael
Freilich, director of NASA’s Earth Science Division.
While sea level rise can now be measured, predicting the rate of
future rise is difficult, because much of the melting by ice sheets
occurs out of sight under the water.
The Greenland ice sheet covers 660,000 miles — nearly the size
of Alaska. Satellite measurements have shown that an average of 303
gigatons of ice have melted each year over the past decade. The
Antarctic ice sheet has lost an average of 118 gigatons per year,
but some new studies suggest it could begin to melt much
faster.
In Greenland, researchers are reporting that one of the largest
chunks of ice ever to break away from land cleaved from the
Jakobshavn glacier in a “calving” event that left researchers
awestruck. More than 4 cubic miles of ice was loosed quickly into
the sea. Check out the news release by the
European Space Agency.
“This is a continuing and evolving story,” glaciologist Eric
Rignot said during yesterday’s news conference. “We are moving into
a set of processes where we have very tall calving cliffs that are
unstable and start fracturing and break up into icebergs …
“We have never seen something like this on that scale before,”
said Rignot, associated with JPL and the University of California
at Irvine. “Personally, I am in awe at seeing how fast the icefall,
the calving part of the glacier, is retreating inland year by
year.”
Other new information from NASA, including lots of graphics:
Because of the holidays, I did not get an immediate response
from several climate experts I contacted following
Nels Sultan’s comments about sea level rise in a blog post
regarding
“king tides.”
Earth at the winter
solstice, Dec. 22, 2011 / NOAA
photo
If you recall, Nels was making the point that the sea level in
Seattle has been rising at a steady rate of .68 feet, or about 8
inches, per century since 1898, as reported by the
National Oceanic and Atmospheric Administration.
His post included this statement:
“There is no real basis for the claims that sea levels will rise
by 2.6 feet or 7 feet, or more. Globally, sea level rise has NOT
accelerated. As found and reported by many researchers who
specialize in this, including the eminent professor Bob Dean and
other coastal experts.”
As a reporter, I’m not inclined to shoot back a response. I’d
rather discuss the issue with experts in the field. That is what I
did, and I think I have a better handle on the issue.
What I’m hearing is that the original estimates by the
Intergovernmental Panel on Climate Change — a rise of between 7
inches and 2 feet by the end of the century — remain reasonable,
but conservative given that they did not account for increased
melting of the Greenland ice sheet. See this
explanation by Stefan Rahmstorf soon after the release of the
2007 IPCC report. By the way, the range above accounts for the
minimum and maximum across six climate-change scenarios.
Ever since, researchers have been trying to find ways to account
for the melting of the Greenland ice sheet, but the uncertainties
remain high. A widely cited paper by
W.T. Pfeffer, J.T. Harper and S. O’Neel suggests that “most
likely” starting point for further refinement is .8 meter, or 31
inches, of sea level rise by 2100.
In some ways, the authors of the Pfeffer paper were trying to
limit some of the extremes being reported by others, so they
concluded that sea level rise could not be more than 6 feet by
2100. Some folks have reported 6 feet as the top of the range, as
unlikely as that extreme may be. Check out this explanation posed
by
Real Climate and this
response by Pfeffer and his collaborators.
As for the Houston-Dean paper that Nels Sultan mentioned, those
authors created “various problems” in their assumptions, according
to Eric Steig, professor of Earth and Space Sciences at the
University of Washington. One major problem was the starting date
of 1930, as explained by
Stefan Rahmstorf in Real Climate:
“Other start dates either before or after this minimum show
positive acceleration. Picking 1930 for this analysis is thus a
classic cherry-pick, and according to the authors that is no
accident. They write in the paper: ‘Since the worldwide data of
Church and White (2006)…appear to have a linear rise since around
1930, we analyzed the period 1930 to 2010.’ The interval was thus
hand-picked to show a linear rise rather than acceleration.
“Houston & Dean use their result to question the future
acceleration of sea level rise predicted by Vermeer & Rahmstorf
(2009) for the 21st Century as a consequence of global warming.
They argue that the 1930s acceleration minimum calls into question
the semi-empirical link between global temperature and global sea
level proposed by us in that paper. However, it is clear they never
bothered to check this, because quite the opposite is the case: our
semi-empirical formula predicts this acceleration minimum,
as the graph above shows. As it turns out, this is an expected
outcome of the mid-20th-Century plateau in global temperature.”
I also discussed this issue of sea level rise with Lara Whitely
Binder, outreach specialist for the UW’s Climate Impacts Group.
While sea level rise means one thing on the world scale, she told
me, the local impacts can be quite different.
If you live in Neah Bay on the Olympic Peninsula, for example,
you are not likely to see any sea level rise until at least 2080.
That’s because the entire land mass is uplifting as a result of
movement along the tectonic plates, and the uplift is predicted to
be faster than sea level rise until late in the century.
On the other hand, Central and South Puget Sound may not be
uplifting at all and could be sinking, which would intensify the
effects of sea level rise. Areas built on fill, including portions
of Olympia, also could be sinking as the fill settles, Lara
said.
In addition to global rise in sea level and local tectonic
shifts, factors affecting regional sea level rise include thermal
expansion of ocean waters and changes in onshore and offshore wind
patterns.
During El Niño events, sea level can rise as much as 12 inches
for several months at a time. The Climate Impacts Group analyzed
more than 30 scenarios from global climate models and concluded
that the change in wind patterns as a result of climate change
could decrease sea level by as much as 1 inch or possibly increase
it by as much as 6 inches. Review the white paper
“Sea Level Rise in the Coastal Waters of Washington State” (PDF 2.4
mb) for more details.
How much an individual property is affected by sea level rise
depends on the slope of the beach. Given the same rate of rise,
water will affect a house sooner when it is built on a gradually
sloping beach as opposed to a steep slope. In any case, tides and
weather will always play a major role in water levels.
Lara told me that a group of West Coast researchers is working
on a new report about sea level for publication later this year by
the National Academy of Sciences. I’ll try to review that paper
when it comes out.
I wish to thank Eric Steig, Lara Whitely Binder, Cliff Mass,
David Montgomery and Nate Mantua for responding to my inquiry.
