60 minutes rewind
one of the most significant efforts to study changes in the climate has been taking place
near the top of the world it's a place called peterman glacier in greenland one of the largest
glaciers in the arctic circle and a glacier that has experienced dramatic melting it is a harsh and
dangerous environment and it has drawn some of the world's leading climate scientists who are only
able to work there a little over a month a year we wanted to see how that work is proceeding how
they're able to move equipment and people in such a hostile place and what they've discovered so far
so we went to the top of the world to find out our journey took us 700 miles above the arctic circle
to the us's thule air force base in northern greenland built at the start of the cold war
to watch for soviet missiles it is an alien landscape home to curious arctic hares
and packs of prehistoric looking musk ox from there hi hi i'm shaker from greenland i'm malik
we flew even further the destination peterman glacier it's on the northwest coast of greenland
just a few hundred miles south of the north pole
to get there in a helicopter took us four hours over a rarely seen
landscape that is both severe and serene
the last town we'd see was konak with 700 residents and more huskies than people
locked in by ice nine months of the year villagers have always hunted seal and narwhal to survive
greenland is three times the size of texas and eighty percent of it is covered in ice
but it now loses more ice than it gains in snowfall every year
we saw evidence of the imbalance everywhere blue gashes across the ice rivers of rushing melt water
and the occasional thunderous crack icebergs dropping into the sea
we still have 300 miles to go stop twice to refuel along the way
these barrels were left behind for us by the scientists who made the trip to peterman glacier
three weeks earlier this is the ultimate self-service gas station
the middle of nowhere this will keep us going for how much longer yeah we can fly two and a
half hours our pilots native green lenders kept a rifle nearby at each stop to protect us from
polar bears have you seen polar bears out here yeah yeah a lot so now it's ready now we're safe
finally we arrived at peterman glacier ah there's the camp and spotted the ice camp below
great to see you so who did you upset to get put out here
keith nichols is an expert in drilling in remote places and in terms of remote this would be really
hard to beat it feels like you're on another planet if you can't take a walk around here you
could be expecting scotty to beam you up it is extraordinary nichols and a team of scientists
were drawn to this remote sliver of greenland in part by these satellite images in 2010 a chunk
of ice four times the size of manhattan broke off then two years later another large chunk came down
the glacier has receded by 20 miles in five years
nichols and his team are trying to drill beneath it this is a lot of work and difficult conditions
what do you hope to learn what we're trying to learn is how the oceans are interacting with
the ice how they're melting it they're trying to predict how in the future that melting might
change to drill through the ice they heated melt water from the glacier to make a hot water drill
to pierce through the 300 foot thick ice there has to be serious challenge to running equipment
like this in this kind of weather the biggest challenge is we've got water and it's very cold
so if we have water freezing and hoses that can be devastating as for the projects this is the
moment the coring machine struck the bottom of the sea floor a half mile beneath the ice
they made history it was the first time anyone has ever collected sediment from beneath the ice
shelf in greenland the ocean beneath ice shelves is probably the least accessible part of the world
ocean and just just getting access to that is a triumph frankly as far as we're concerned
the ice shelf extends out from the glacier and floats on the ocean they believe it acts like a
dam holding back the ice from sliding into the sea if it goes away sea levels go up is there
a sense of urgency in the work that you're doing so sea level rise is the big is the big question
that we're trying to get at and peterman glacier this experiment here gives us an opportunity
to get at those processes to start to try and understand the basic physics as to how that can
happen our visit to the ice camp was cut short our pilots warned us something called ice fog
was moving in and could strand us here for days we hightailed it back to the helicopter
heading to another outpost of the expedition what the scientists call boulder camp set up on
the edge of peterman glacier sean marcotte and a team of geologists have been here for weeks
gathering samples from rocks so this was probably deposited when the ice was maybe
a few hundred to a few thousand feet thicker and when it was deposited you're probably talking
about maybe five six hundred feet of ice above us above where we are above where we are now peterman
would have been much larger and it would've been dropping these rocks all over the surface to
the person at home who's looking at you guys just chipping away at rocks and going why should i care
about this we know that if you warm the planet up glaciers respond they melt the question is
at what rate how fast is that going to happen and where is it going to happen and where are the most
vulnerable spots of this ice sheet to understand all that you have to understand how the ice sheet
what controls an ice sheet we need to understand this glacier so that we can provide a better
prediction for the larger ice sheet that matters to us because of sea level if these glaciers can
respond dynamically then we should all be concerned because that can create dynamic changes
in sea level and flood infrastructure and we need to know that for planning for the future we camped
out next to the scientists with 24 hours of light we slept in these tents under the midnight sun
in the morning we were shuttled out to meet the odin a swedish
icebreaker making its way around peterman glacier
yoden supports the scientists on land and acts as a floating laboratory
named after a norse god who relentlessly sought wisdom
it's home to more than 50 climate scientists from around the world with similar convictions
their work is funded mostly by the swedish government and the us's national science
foundation larry mayer is one of the geologists on the odin he's using sonar to map the ocean floor
creating the first detailed maps that show how peterman glacier slid into the sea
you can see it like skid marks of a car at an accident scene yeah the ice went here and
the ice went there and we can see now it has stopped here how much of the world's
oceans have been mapped with this kind of detail oh probably uh on the order
of six or seven percent very very little yeah the story will continue after this
you can only make the trip to peterman glacier a few weeks each summer when the ice melts enough
to allow passage you can see those blocks of ice drifting by expedition leader allen mix
is running the ship's coring operation trying to grab sediment from the sea floor it's actually our
coring site right now is under that block of ice and we just can't get there so we're we're trying
to drift with the ice and just sort of sneak up on it gently it's hard to sneak up on anything in an
icebreaker yoden doesn't so much a sail as it does smash the ice like a 13 000 ton hammer
once in position they throw something called a piston core like a dart at the bottom of the ocean
oh that doesn't sound good after multiple attempts go to the next one but we'll hit it with a gravity
cord a core sample like this is collected inside the ship's lab the multi-year process of
investigating those cores begins what's your best guess how old is this so the base of this core
probably is no more than ten thousand years ann jennings is with the institute of arctic
and alpine research she says each core holds clues about peterman glacier's past
well we didn't really expect to find things living under the ice shelf but we have what have you
found this one we found is called sibicidoides wool or storify it has a big name for a little
easy for you to say it looks like a little seashell and it is a seashell but it's a single
celled animal that single single-celled animal like all living creatures is made out of carbon
allowing scientists to determine when it lived which tells you what the age of the sediments so
we can take them the depth scale here and convert it to age and then we can say when did the ice
retreat how quickly did it retreat was there a lot of melt water coming out you can get all that from
what looks like mud yes after a week in greenland we headed home but the scientists kept working
taking advantage of the final days of the short arctic summer the 66 core samples they collected
during their month at sea will be studied by scientists around the world for decades
this is the largest core repository in the world peter dominical is a paleoclimatologist
at columbia university he says the cores collected in greenland are like a black box of the earth's
inner workings this one he collected just south of greenland so this is today's climate and we've had
about 10 000 years of relatively warm climate and then we go 10 000 years in the past boom there's
the last ice age this is when long island was formed when cape cod was formed and go on you
can just find this color and this is filled with these rocks what we call ice rafted detritus
until this period when whoa there's another warm phase and then another cold phase and then another
warm phase a short cold phase a longer warm phase and then boom another ice age and so you've had
cold warm cold warm cold warm today how do we know that the warming we're seeing now how do we not
know it's part of this warm cold warm cold that's a great question these transitions are gradual and
kind of almost like a tide wave or something and this transition when you get to today goes boom
suddenly very warm dominican says the cores pulled from peterman glacier will fill in a crucial piece
of the climate change puzzle how impressive was it that they
got to peterman glacier it's impressive what's more impressive is that we haven't been there
every year and that we're not going not doing this every year we should be doing this
we should be monitoring this whole system with much greater uh focus than we are now
how quickly have we seen the changes in greenland the changes that are happening right now as a
result of human activities are remarkable and they're happening incredibly fast and they're
it's not only happening fast but it's accelerating and it's important to really get our mind around
what we're saying there we're not just saying that climate in the arctic is changing it's changing at
an accelerating rate so it basically means it's starting to melt but it's melting at a faster
and faster clip so anyone who knows what it's like to fall off a cliff that's what it's doing