tonight about Arctic ice management
which is a term I coined which means two
things to me it means a call to arms to
do something to preserve and restore the
sea ice in the Arctic and also a
possible means of doing so you may be
wondering Steve you are an
astrophysicist you are a planetary
scientist what are you doing talking
about the Arctic is so far away
especially from Arizona we in the desert
maybe you have a romantic notion of the
Arctic as I do it is this distant place
you know nobody even visited the Arctic
the North Pole until 1926 so it’s only
been a century that people have explored
its full extent and it seems as a place
that is ancient and unchanging and
difficult to cross and so we may
remember that there were people who are
attempting to go through the Northwest
Passage –is these areas in the
northwest part of Canada for centuries
and this is a depiction of the 1830’s
attempt where a ship is mired in the ice
and in 1845 the doomed expedition of
Franklin this is not an easy place to
get to
we think it’s formidable ancient
unchanging but it’s not it is changing
rapidly this is a more recent picture of
the Nordic Orion which is a cargo ship
which in 2013 carried coal from
Vancouver through the Northwest Passage
to Finland and even more recently last
September you could have booked a cruise
on the Crystal serenity cruise ship
which went through the Northwest Passage
–is something that people had tried for
centuries to do but is now something
that can be done for tourism things are
changing the Arctic rapidly the passages
are open it’s an historic event we are
going to see this more and more as the
years go by says the director of the
national snow and ice data center what
is changing the Arctic is simple to
understand the Arctic is melting as
climate change is happening and
temperatures are increasing we have
increasingly less ice in the Arctic this
is a graph depicting the amount of ice
the volume of ice in thousands of cubic
kilometers versus every month of the
year
so this is
the normal trend this is the average
from the 80s and 90s and to thousands of
how much ice there is in January it is
maximized at the end of Arctic winter in
April it melts during the summer and is
a minimum in September and then it
freezes again during the Arctic winter
and the gray band denotes the the
average amount and what is normal the 1
into Sigma levels these colored lines
show the results from the 7 most recent
years and you can see that every year
less ice exists in the winter less ice
freezes in the winter more ice melts in
the summer and the red line is this year
and this is hot off the presses
quite literally this is a record low
amount of ice for this time of year if
you plot the amount of ice that exists
at the maximum time this time of year
the end of the winter every year it’s
getting smaller and this is the amount
that exists at the end of the summer the
minimum amount and every year it’s
getting smaller these trends tell us
that every year there’s 300 cubic
kilometres less ice on average than the
year before and to visualize this
imagine an ice cube 4 miles on a side we
have one less of those every year and
there aren’t an infinite number of these
ice cubes as you can see these trends
past the line of zero ice by the end of
the summer in around 230 2030 and that’s
a time when we’ll have no ice in the
Arctic at the end of the summer and
graphs are one thing I think this visual
will help you visualize what’s going on
this is a depiction of satellite imagery
from NASA of how much the ice extends
over the Arctic during September of each
year and from the dawn of the satellite
era in the late 70s through the 80s you
have a typical amount of ice at the end
of the summer
over half of the arctic’s covered but
starting in the late 90s you start to
see that the extent of the ice is
significantly less and the years 2007
and 2012 are particularly low and this
is happening more and more each year so
it’s easy to see how we are quickly
reaching a state where there will be
practically no sea ice at the end of the
summer and that’s bad for the Arctic
multi-year ice is stronger without
multi-year ice
I used to persist through the summer
it’s harder for ice to freeze in the
winter and the ice is weak or more
easily disrupted and carried southward
so this matters as well for the
reflectivity of the earth the Arctic is
the world’s air conditioner it reflects
back a lot of sunlight the sea ice is
reflective but in 2012 this much area of
the Arctic was missing ice compared to a
typical year of 1979 this area was much
darker than previous years and that is
because sea ice reflects back over 90%
of the sunlight that hits it whereas
once that ice melts and you have open
ocean it absorbs over 90% of the
sunlight this is a runaway process once
you melt ice and the sunlight is
absorbed into the ocean the temperatures
increase and that makes it easier for
the ice to melt and makes it harder for
it to freeze again in the winter we call
this the ice albedo feedback albedo is
the ability of something to reflect
light and that feedback is one of the
reasons why temperatures are increasing
faster in the Arctic than anywhere else
this is a graph from 1880 to the present
day of global temperatures that’s the
black line and they have increased by
about a degree centigrade over the last
century but the blue line denotes the
temp
in the Arctic and they have been
increasing at a faster rate and they are
much warmer today than ever before this
is one feedback that exists in the
Arctic and another feedback is the
methane release feedback there are
regions of the globe around the Arctic
that are permanently frozen the
permafrost regions are denoted in this
dark blue these are regions that have
stayed frozen since the last ice age but
they’re beginning to thaw and as a
result they are releasing methane
methane natural gas is something that is
naturally found in swamps and other
places where your vegetative decay and
that methane has remained trapped under
the permafrost since before the ice age
but now that the permafrost is thawing
it’s releasing methane so much that you
could ignite it just like the burner on
your stove we have seen methane
emissions increase from half a million
tons per year 20 years ago to over 17
million tons released in 2013 this is a
problem that’s accelerating because of
the feedback the ice I’ll be too a
feedback because of the methane feedback
what happens in the Arctic affects the
entire climate system and because of
these feedbacks it turns out the Arctic
is one of the most sensitive places to
the climate that’s happening elsewhere
in the world and the more I learned
about this and the more I understood the
problem the more compelled I felt to do
something about it
so in 2013 I taught a class with my
colleagues here at ASU Hilary Hartnett
and Chris crappie where we explored
these issues and we explored a possible
technology that I came up with for
possibly restoring some of the sea ice
and restoring the Arctic to it’s cooling
role in the climate we taught this class
and we explored some of these aspects of
this technology and then finally we
published our results in the refereed
journal Earth’s future and this is a
copy of the paper and all the students
were made co-authors something that
we’re quite proud of the idea expressed
in this paper is one we have to do
something about the Arctic but also
here’s something that might work the
idea is quite simple if you had a device
of
we that you put out into the ocean in a
place where multi-year ice was not
forming and you left it there in the
summer then as the winter came and the
ice started to freeze around it this
buoy would support a wind turbine and
there is plentiful wind power in the
Arctic even through the Arctic winter
and that wind power could be used to
raise water from below the sea ice which
is only a few meters thick raise it up
to above the sea ice where it would be
held in a tank until distribute it and
then distribute it over the ice where it
would freeze more rapidly
right now the freezing of seawater into
sea ice is limited once the ice gets to
be more than a few meters thick because
the ocean is relatively warm and the
cold part is on the top by putting the
water on top it freezes faster and we’ve
calculated these effects by our
calculations we estimate that one device
like this could increase the thickness
of sea ice over the course of one Arctic
winter by about one meter over an area
of 1/10 of a square kilometer now one
meter doesn’t sound like a lot but these
are the average depths of the sea ice
throughout the Arctic and it’s no more
than a few meters and in most places
it’s less than a meter so if you could
add one meter to the thickness of the
ice you would significantly increase the
volume of ice that’s there and we
estimate that ten million devices
distributed over a million square
kilometers 10% of the area of the Arctic
could actually produce a thousand cubic
kilometers of ice extra per year and
offset the loss of ice that we’re seeing
10 million that seems like a big number
but I want to remind you that we make in
this country 10 million cars every year
and these are not as complicated as cars
so it’s something that we decided in the
paper is feasible doable and if we could
employ these we might see 10 million of
these devices increase the amount of ice
and restore the the Isis there now to be
sure we’re not trying to solve all of
the world’s climate change problems we
can’t until co2 emissions are brought
under control but what we are advocating
is studying this method for reducing the
worst of the feedbacks for footage
pushing on the
break rather than the accelerator in the
Arctic now this may sound like
geoengineering and it is it’s a project
where we are purposely intervening in
the climate to change something about it
but we think it’s relatively benign
compared to some standard geoengineering
concepts such as stratospheric aerosol
injection where sulfuric acid is sprayed
into the stratosphere suspended there
for months to reflect back sunlight that
will cool the earth but with other
effects or iron fertilization of the
oceans where iron is poured into the
ocean to help fertilize the growth of
plankton which would draw down co2 these
are ideas which have been discussed and
each of them has effects and our project
may also have effects that we haven’t
thought through but the point is that
it’s relatively benign because what
we’re doing is trying to get a natural
process to go a little bit faster to
restore the ice to the state that it
existed in just 20 years ago our next
steps are to build and test a prototype
to see if such a device could actually
survive the Arctic winter
and whether it would thicken the ice as
advertised and to improve the modeling
we need to understand how this would
affect ice in the Arctic spraying salt
water over ice can weaken it we need to
understand all of these things but if
the choice is to not have ice or to have
this ice we think that it’s better but
we need to model at all and our goal is
to provoke a technical discussion and
also a non-technical discussion it’s
important to widen the dialogue to bring
in the relevant stakeholders and the
people who live in the Arctic and
discuss the ethics of such projects and
who would manage such projects and I
just want to leave you with one final
thought which is that climate change is
a big problem and the loss of sea ice in
the Arctic is staggering in its scope
but climate change is an accidental
byproduct of our great industrial
capacity and we have the ability to
great things and if one small fraction
of our capacity was directed at solving
these problems I have every hope that we
can restore the ice in the Arctic and
buy us time to work on all the other
problems too we have great powers as a
species we have great imagination and
innovative capability as a species what
we don’t have is time
thank you [Applause]