Disappearing Glaciers - Evidence of A Rapidly Warming Earth
"Since 1963, the Qori Kalis glacier
in Peru's Quelccaya ice cap in the Southern Andes has shrunk by
at least 20%. The rate of retreat has been 509 feet per year,
or 1.3 feet per day! You can literally sit there and watch it
retreat. And if you assume that the current rate of retreat will
continue, this ice cap will disappear some time between 2010 and
- Lonnie Thompson, Ph.D., Glacial Geologist, Ohio State University
the American Association for the Advancement of Science (AAAS)
meeting in San Francisco on February 25, 2001 Prof. Lonnie Thompson
from Ohio State University's Department of Geological Sciences
presented a paper entitled "Disappearing Glaciers - Evidence of
A Rapidly Changing Earth." He spoke before a special session of
Earth Systems Science: The Quiet Revolution, organized by the
International Geosphere/Biosphere program. Dr. Thompson has completed
37 expeditions since 1978 to collect and study perhaps the world's
largest archive of glacial ice cored from the Himalayas, Mount
Kilimanjaro in Africa, the Andes in South America, the Antarctic
Thompson reported to AAAS that at least one-third of the massive
ice field on top of Tanzania's Mount Kilimanjaro has melted in
only the past twelve years. Further, since the first mapping of
the mountain's ice in 1912, the ice field has shrunk by 82%. By
2015, there will be no more "snows of Kilimanjaro."
Peru, the Quelccaya ice cap in the Southern Andes Mountains is
at least 20% smaller than it was in 1963. One of the main glaciers
there, Qori Kalis, has been melting at the astonishing rate of
1.3 feet per day. Back in 1963, the glacier covered 56 square
kilometers. By 2000, it was down to less than 44 square kilometers
and now there is a new ten acre lake. It's melt rate has been
increasing exponentially and at its current rate will be entirely
gone between 2010 and 2015, the same time that Kilimanjaro dries.
the Himalayas, a recent ice core in fall 2000 from the Dasuopu
Glacier at 26,293 feet on top of Mt. Xixabangma on the southern
edge of the Tibetan Plateau indicated that the last 50 years have
been the warmest for that ice cap in at least 9,000 years. That
conclusion is based on oxygen isotope measurements from the Tibetan
ice cores that indicate what the original temperatures of the
source waters were before freezing.
Thompson, Ph.D., Professor of Geological Sciences, Ohio State
University and Senior Research Scientist, Byrd Polar Research
Center, Columbus, Ohio:
have drilled four sites in Tibet. We have drilled in Russia, Tanzania,
Peru, Ecuador and Bolivia in South America. We also have ongoing
programs in Greenland and down in Antarctica. So we have drilled
on just about every continent.
ALL OF THE ICE CORES, WHAT IS THE CURRENT STORY ABOUT GLOBAL CLIMATE
Well, the earth is getting warmer. There is no doubt about that.
You see it whether you are looking at the oxygen isotopes which
are one of the parameters that we measure on these ice cores that
we collect. Oxygen isotopes are a proxy for temperature in ice.
They record a temperature of the source area - the oceans where
the water vapor comes from that makes up the snow as well as the
temperatures at the area where condensation takes place that forms
these glaciers. And from those, you can see the seasonal temperature
variations in winter, summer. So, when you analyze the cores, they
are layered very much like a tree and you start with the year you
do the drilling and count the layers back in time. And in Tibet,
for example, every site - all 4 sites we have drilled - the real
consistent story in the records is the enrichment, the warming,
that the isotopes show over the last 200 years, starting about 1800
and coming up to the present. So, it's a very consistent signal
there, and also very consistent with the meteorological stations
from the Tibetan Plateau. There are about 178 stations up there
at different elevations.
If you look at the temperature records from those stations, you'll
see that temperatures have been warming on average about .16 degree
Centigrade per decade. Those records stand from 1955 up through
about 1996. And the interesting thing about those station records
is that the stations from the highest elevations show the greatest
warming. At the highest sites right at the top of the plateau, temperatures
have been warming at about .35 degrees C. per decade.
highest ice cores ever recovered on earth come from the top of the
Himalayas at 23,500 feet. There we have the greatest isotopic enrichment
occurring in the last 50 years and that enrichment is greater than
anything in the last 1000 years for that site. And in fact, greater
than since these particular ice fields started to form.
WOULD BE BACK HOW MANY THOUSAND YEARS?
least 8,000-9,000 years.
IN THE LAST 9,000 YEARS THERE HAS NEVER BEEN A PERIOD THAT HAS WARMED
UP AS RAPIDLY AS IT HAS IN THE LAST FIFTY YEARS?
DO YOU EXPLAIN THAT AT THE HIGHER ELEVATIONS THAT THERE WOULD BE
a very important question and one that we have been looking into
because when you look at the details of the glaciers in Peru, for
example, they are not only retreating but the rate of retreat is
accelerating. We are trying to figure out what is driving that and
one theory is that what is happening in the Tropics - that's where
the energy that drives the climate system comes into the planet.
It's also where water vapor is evaporated from the earth's oceans
and goes into the climate system. We think as the earth warms in
the Tropics, we are getting greater evaporation at the surface down
where most of our instrumental records, meteorological stations,
are located. Evaporation is a cooling process, but it's really a
transfer of heat from the surface of the ocean and water vapor gets
tied up in these deep convective cells that make up the inter-Tropical
convergence zone and have very heavy rainfall. And when you have
condensation taking place, this heat is released.
we start in Tibet - the last glacier we visited in the central part
of Tibet. We were the first westerners, the first people to go into
that area. Very remote. No roads. But we had a map. The map of the
glacier, Puruogangri, was made from aerial photographs that the
Chinese took back in 1974. And in the year 2000, all the lobes coming
off of that ice cap onto the plateau had retreated 1 to 2 kilometers
since that map had been made.
we go to Kilimanjaro where we drilled in the year 2000 also, as
part of the project we recovered six cores to the bedrock from the
ice fields on top of Kilimanjaro. But on Feb. 16, 2000, we also
had aerial photographs taken of the ice fields. And from those,
we were able to make a map of the area of ice that's on the mountain
in the year 2000. And that turns out to be 2.2 square kilometers.
first map of the Kilimanjaro ice field was made in 1912 and there
have been five maps, including ours, that have been made from 1912
to 2000. In 1912, there was 12.1 square kilometers of ice on the
mountain. So, that means that since 1912, 82% of the area of ice
has disappeared. The last map that was made before we made ours
was in 1989. In 1989, there was 3.3 square kilometers of ice which
means that 33% of the area has decreased from 1989 to the year 2000.
you can take all five of those maps, you can map out the area that
existed as you come forward in time, and you get a line that if
you project it into the future will show those ice caps disappearing
gone in another 14 years. And that is assuming there is no increase
in the rates of the warming of the atmosphere.
RIGHT NOW ALL OF THE PROJECTIONS OF THE (United Nations) INTERGOVERNMENTAL
PANEL ON CLIMATE CHANGE SAY THAT IT WILL CONTINUE TO KEEP INCREASING.
believe that's what will happen, yes.
MEANS THAT THE GLACIER ON TOP OF MT. KILIMANJARO COULD ACTUALLY
BE GONE SOONER THAN 2015?
correct. We think that's a conservative estimate. But if it just
maintains the rate of retreat that we've seen since the first map
was made in 1912, it will be gone by 2015. So it's remarkable when
you think about the history of that area, Ernest Hemingway and The
Snows of Kilimanjaro and the like. For the people who live there,
of course, it has tremendous implications for tourism. Some 20,000
tourists come to Kilimanjaro every year. It's the only mountain
in the world that I know that has its own international airport.
So, the local hotels and tourist industry are very concerned about
what's happening in that area.
it also has implications for the local towns like Moshe and Arusha
because the mountain serves as a water source. A lot of that water
comes from the rains that occur on the lower levels of the mountain.
But glaciers kind of serve like a natural dam. They accumulate snow
in wet periods and when there is an abundance of precipitation and
it kind of waste melts when it's drier, so they kind of maintain
water flow in the stream in dry periods. So, when the ice caps are
gone, we would expect greater variability in water supplies in that
Retreat of South American Glaciers
if you go to South America where we have our longest documented
records and that's because it was the first place that we went to
drill tropical ice cores. I first went to Peru in 1974 and we went
to look at this ice cap called Quelccaya that at that time covered
56 square kilometers. It's probably the only true ice cap in the
tropics - very flat body of ice on the basalt flow, some at elevation
18,700 feet. As part of our ice core drilling program there, way
back in 1978 we set up a baseline, a line where we measured the
distance very carefully where we could take terrestrial photographs
of the largest outlet glacier, the Qori Kalis, which flows to the
west off of the Quelccaya ice cap. We could take photographs and
map that glacier not only at its terminus, but also map the volume
changes of ice through time. We did that back in the 1970s when
no one was talking about global warming and no one was talking about
global change. But we have revisited Quelccaya repeatedly to get
a documented record of the change taking place there.
first map of this Qori Kalis glacier comes from 1963 aerial photographs
and our first terrestrial photographs were in 1978. And if you look
at the rate of retreat from 1963 to 1978, it was 4.9 meters per
year. We went back and re-photographed the glacier in 1983. Between
1978 and 1983, the rate of retreat had increased to about 8 meters
per year. We went back again in 1993 and photographed Qori Kalis,
and from 1983 to 1993, the rate of retreat had increased to about
14 meters per year. Then from 1993 to 1995, the next time we measured
it, the rate of retreat had increased to 30 meters per year. Then
from 1995-1998, it had increased up to 49 meters per year. And from
1998 to August 2000, the last time we mapped it, the rate of retreat
had increased to 155 meters per year.
ALMOST AN EXPONENTIAL MELT RATE.
IS an exponential melt rate. It's 32 times faster today in the rate
of retreat than it was in that first period from 1963 to 1978. Since
1963, the Qori Kalis glacier in Peru's Quelccaya ice cap in the
Southern Andes has shrunk by at least 20%. The rate of retreat has
been 509 feet per year, or 1.3 feet per day! You can literally sit
there and watch it retreat. And if you assume that the current rate
of retreat will continue, this ice cap will disappear some time
between 2010 and 2020.
SAME TIME PERIOD AS THE DISAPPEARANCE OF MT. KILIMANJARO.
MANY OTHER OF THE WORLD'S GLACIERS THAT YOU HAVE BEEN DEALING WITH
WILL ALSO BE GONE BY 2015?
power company in Peru, Electric Peru, has been monitoring the terminus
of glaciers since 1945 on about six other glaciers in northern Peru.
Every one of those glaciers show retreat and they show the same
acceleration in the rate of retreat that we have just talked about
on Qori Kalis and the Quelccaya ice cap in the south. And so, already
in Peru, the power company is worried about hydroelectric power
production. In the dry season in the Rio Sante River Valley, the
plant produces 100% of capacity in the wet season and that drops
to 20% capacity in the dry season. In Peru, there is a very strong
dry season in June, July and August and the only water comes from
the melting of these glaciers. So, once the glaciers are gone, there
will be very little water in those valleys.
ARE THEY GOING TO GET POWER?
cities like Lima, Peru, a city out in the desert, coastal desert,
has 9 million people - they've already started to build fuel-burning
power plants to make up for the loss of power and the extra need
of power because population continues to increase.
BUT THAT CONTRIBUTES MORE CARBON DIOXIDE
INTO THE ATMOSPHERE AND ACCELERATES THE WARMING.
exactly right. And we believe that in ten to 20 years, a lot of
these ice fields - if you want to see and look at tropical ice -
you'll have to come to the freezers here at Ohio State where we
have an archive. We are storing an archive of these cores frozen
at -40 deg. C. because we know that there will be new technologies
and advancements in understanding that you won't be able to go out
into the natural world in the tropics and recover some of these
ALL THE ICE WILL BE GONE
IS YOUR OWN PERSPECTIVE ABOUT BOTH THE POLAR MELTS AND WHERE THINGS
ARE HEADED AND WHAT COULD HAPPEN IN ANTARCTICA?
have two big ice sheets on the earth, Greenland up in the Arctic
regions and the Antarctic ice fields. These are where most of the
fresh water on earth is contained. And for sure, the Arctic sea
ice has been thinning and as the temperature of the world continues
to warm, I believe that one of the things we need to be concerned
about is - We know for example, that 1998 was the warmest year on
record. That's the warmest year since we've had instrumental records
on the planet. We also know that the decade of the 1990s was the
warmest on the planet. We also know from our proxy records - tree
rings, ice cores, corals and the like - that the 1990s was probably
the warmest decade in the last 1000 years, at least. And we know
the glaciers are melting and retreating. But we also know that the
glaciers and oceans of the world serve as a buffer. As the temperatures
warm, that energy, some of that energy, is going into melting the
glaciers and warming of the oceans. But once the glaciers are gone,
then you don't have these buffers for future temperature rises.
So we have to be concerned about the natural balance that exists
on the earth for trying to maintain the ways it maintains its temperature.
IF WE LOSE ALL THE ICE, THEN WHAT HAPPENS?
we would expect temperatures to accelerate. You have to always remember
that the earth's climate has changed through time. There have been
warmer periods. There have been colder periods. Natural variations
in climate systems. The difference is as we go into the 21st Century,
there has never been 6 billion people on the planet. There has never
been a time when we were adding 200,000 people a day to that number.
And probably even more telling is the fact that most of these people
on the earth are poor. Most of them are striving to have a life
style like western cultures and you can't blame them. But to do
that, they must increase consumption. To increase consumption means
you must produce more product. To produce more products, you must
burn more fuels. So, it's not only the fact that the population
is increasing and we're at these record levels in the history of
the planet, but the fact is that our rate of consumption is increasing
know from the ice core studies that have been done in Antarctica
that if you look at the long term history of CO2 in the earth's
atmosphere, it varied due to natural changes and during glacial
periods it's very low - on the order of 180-200 ppm by volume.
warm periods, it gets up to 280 ppm by volume. But we crossed 300
ppm by volume in 1900. We're now at 370 ppm by volume. Sixty years
out, if we go about business as usual, we'll be at 600 ppm by volume.
we've entered what at least in the history that we have good CO2
measurements, a period that there is no analog in the natural system.
So, we don't know exactly how the system will respond to this. But
we do know these gases have long residence time. Again, another
argument why - if you don't know how the system is going to respond
to something like this, then we should be taking the first steps
to reduce those emissions until we better understand how the climate
system works.That's why when you do the business as usual projections,
you see the CO2 doubling, tripling in the earth's atmosphere.
NO PRECEDENT FOR THAT, AND SCIENTISTS INCREASINGLY SAYING THAT WE
ARE HEADED INTO SUCH UNKNOWN TERRITORY WITH SUCH UNPREDICTABLE CONSEQUENCES
THAT IF THE PLANET DID WARM ANOTHER 10 DEGREES IN THE NEXT 100 YEARS,
THE CONSEQUENCES COULD BE SEVERE.
that's where we're headed, yes. But any time you look at a model
prediction of the future, it's based on what we know today and what
we know from the past. But we always have to remember that the earth's
climate system has always changed. There have been periods when
it has warmed and cooled. If all the evidence we have was only the
ice, I wouldn't be so concerned. But it comes from our instrumental
records. It comes from tree ring data. It comes from ocean temperatures.
From corals. That when you look at the balance of that evidence
the earth is getting warmer and there is no reason to believe that
it's going to reverse in the near future."
DO YOU THINK AS A PERSON STUDYING ICE CORES
THAT THERE IS ANY CHANCE THAT SOME OF THOSE BIG ICE SHELVES THAT
ARE ON LAND IN ANTARCTICA COULD SLIDE OFF INTO THE OCEANS IN THE
NEXT 100 YEARS?
in the Antarctic peninsula area, these ice shelves have been breaking
up here recently. Unfortunately we don't have a long term history
to know if this has happened in the past under natural conditions.
But we know that in the area in the peninsula since the first meteorological
station was put in there, temperatures have increased 2.5 deg. C.
And we have the break up of the ice shelves taking place.
big ice sheets in the interior - they have a much longer response
time to temperature changes. You have to look at Vostok in central
east Antarctica. Temperatures there are minus 55 deg. C. So, if
you raise the temperature 10 deg. C., or 5 deg. C., it's still cold.
And so the response time there is slower.
I think that we expected to see the first changes taking place in
the tropical glaciers because they set right at the snow line, zero
isotherm, and therefore, if temperatures of the earth rise, they
will respond. They will see it first. I refer to them as the "canary
in the coal mine." In the old days they used to take canaries down
in a cage and if that canary died, it meant there was methane in
the mine and the miners got out. I think the tropical glaciers are
in a way the earth's early warning signal of the increasing temperatures
of the earth.
WAS THE LAST TIME THAT ANTARCTICA HAD NO ICE ON THE LAND?
debated. But it's on the order of 30 million years ago. You'll find
other people who say it was only 3 million years ago, but a long
time ago. But certainly a time when we didn't have this human population
on the planet. It's a fact that you can look at these glaciers and
we have these series of photos we have collected over so many years
that is so compelling because glaciers have no political agenda.
All they do is respond to their environment. That's what they are
THEY ARE MELTING.
they are melting!"
© 2001 Linda Moulton Howe All Rights Reserved. Republication and redissemination
of the contents of this screen are expressly prohibited without prior
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Ice-Melt 'Speeding Up'
David Shukman BBC environment and science correspondent in Greenland
First you hear
a savage cracking sound, next the rolling crash of thunder.
Then as the icebergs rip away from the margin of the ice-sheet
they plunge into the grey waters of the Atlantic with a roar that
echoes around the mountains.
Nothing prepares you for the sheer scale and drama of events in
this forbidding terrain and all the signs are that the changes
at work here are gathering pace.
only way to reach the ice-sheet is by helicopter - a spectacular
flight through remote fjords and the jagged blue-white rubble
of the ice.
We travelled with Danish scientist Carl Boggild of GEUS, the Geological
Survey of Denmark and Greenland.
For the past few years he has been managing a network of 10 automatic
monitoring stations and his first results are alarming - the edges
of the ice-sheet are melting up to 10 times more rapidly than
earlier research had indicated.
Cracks and Crevasses
In 2001 NASA scientists published a major study based on observations
by satellite and aircraft.
concluded that the margins of the Greenland ice-sheet were dropping
in height at a rate of roughly one metre a year.
Now, amid some of the most hostile conditions anywhere on the
planet, Carl Boggild and his team have recorded falls as dramatic
as 10 metres a year - in places the ice is dropping at a rate
of one metre a month.
glacier we visited - the Sermilik glacier in southern Greenland
- is so volatile that one automatic monitoring station was lost
into a yawning crevasse.
Between a maintenance visit in May and our visit this month, new
cracks had opened up in the icy surface and we had to help shift
one of the devices to a safer position.
Engravings from the late 19th Century show how the glacier once
reached far into the ocean and satellite pictures highlight how
the retreat has accelerated - the glacier dropping an astounding
150 metres in the last 15 years.
The latest data shows the melting picking up even more speed.
vicious wind whipping across 2,000 kilometres of solid ice - the
length of the Greenland ice-sheet - chilled us as we filmed.
But the feeling of cold was ironic - it is the rise in air temperatures
recorded here that is at least partly responsible for the sudden
acceleration of the melting.
Dr Boggild and his colleagues, studying the physics of how the
air and ice relate, conclude that as much as 55% of the melting
is attributable to warming in the air.
He is cautious to avoid blaming climate change too readily: "Maybe
if we look back after 50 years and see how temperatures have risen,
then we can call it climate change."
Sea Level Rise
Dr Boggild is all too aware of how easily he could be accused
of jumping onto a climate change bandwagon.
But he is adamant that the results he has gathered so far are
"We can say for certain that the rate of melting has increased
and we can say for certain that the height of the ice-sheet is
falling, even allowing for increased ice-flow.
"There is no doubt that something very major is happening here."
we speak, he checks the instruments on the automatic station.
A large range of data is collected and transmitted via satellite
to Copenhagen every six hours.
For the first time, scientists should have a long-term, on-the-ground
view of the changes taking place here.
Just before we leave, there is another roar as more icebergs crash
into the ocean.
more icebergs falling into the sea will cause two things to happen
- the sea-level will rise and the injection of freshwater could
disrupt the ocean currents, including the Gulf Stream.
What happens in this remote barren land has the potential to affect
following update is an example of the accelleration of glacier
loss - ten years earlier than projected - which was addressed
in this 2,000 article written by Linda Molton Howe. The metaphore
used by the scientific community then was that the loss of equatorial
glaciers would have warning repercussions for humankind that equal
to the death of a canary in a coal mine. (editors note)
Jeremy Lovell, Reuters
Mount Kilimanjaro Shows No Snowcap
for First Time in 11,000 years
in London for a two-day brainstorming session on the environment
agenda of Britain's presidency of the Group of Eight rich nations,
the environment and energy ministers from 20 countries will
be handed a book containing the stark image of Africa's tallest
mountain, among others.
''This is a wake-up call and an unequivocal message that a low-carbon
global economy is necessary, achievable and affordable,'' said
Steve Howard of the Climate Group charity which organized the
book and an associated exhibition.
''We are breaking climate change out of the environment box.
This crisis affects all of us. This is a global challenge and
we need real leadership to address these major problems -- and
these ministers can give that leadership,'' he told Reuters.
The pictures include one of Kilimanjaro almost bare of its icecap
because of global warming, and coastal defenses in the Marshall
Islands threatened with swamping from rising sea levels.
Prime Minister Tony Blair has vowed to make climate change and
Africa the twin targets of Britain's presidencies of both the
G8 and European Union this year -- bringing both to the fore
at a summit meeting in Gleneagles in Scotland in July.
Kyoto Protocol on cutting emissions of greenhouse gases came
into force in February but is still shunned by the world's biggest
emitter, the United States, and puts scant limits on China,
rising fast up the ranks.
officials from both countries will be at the London meeting,
whose main thrust is how to achieve the environmental Holy Grail
of a sustainably growing low carbon economy.
''There is an attempt to draw the United States in after its
refusal to sign Kyoto,'' said a spokeswoman for environmental
pressure group Greenpeace.
''It is very sensitive given that the developing countries are
trying to climb the development curve and the developed countries
must not be seen to be doing anything to hold them back,'' she
senior official at Britain's Department of the Environment,
Food and Rural Affairs, which is co-organizing the meeting --
the first of environment and energy ministers from developed
and developing nations -- said the aim was to find common ground.
''This is a chance for people to get together and by not forcing
them to negotiate a very concrete outcome ... allow them to
explore common interests,'' she said.
''There are plenty of technologies out there which we can deploy
which can help with that shift (to a low-carbon economy) straight
away. We know that energy efficiency can already deliver huge
carbon savings at a net benefit to our society,'' she told Reuters.
British think-tank the Institute for Public Policy Research
has proposed a multi-tiered approach, calling for progressively
deeper cuts in greenhouse gas emissions by rich nations but
more flexible commitments from the developing world.
should be made against the backdrop of long-term efforts to
take Kyoto -- with the United States and Australia aboard in
some form -- beyond the end of its first phase in 2012, it said.