The side effects
of global warming are many, and many of these will adversely
affect both the environment and mankind, as we shall see by
the time we're done looking at all the evidence. Many of you right now may think global warming is a
big hoax, an assortment of "junk
science". But as we shall see, the science portion comes
from the world's top scientists in their respective fields. Instead, many of us have been guilty of forming
amateur opinions about some very real scientific discoveries. So hang on, you're going to go for a real ride,
and come to realize some very scary facts about where we are
in the realm of prophecy. This article is primarily written for Christians, many
or most of whom are spiritually slumbering, as Matthew 25
indicates. Let's list
the side effects of global warming, just for openers. Global warming is simply the steady raising
of the earths average mean temperature over a period of time,
without a drop back to previous levels.
Listing the side effects of global warming will help
us fill in the picture of what's happening around the world
due to this steady temperature rise. After listing these side effects we'll take
a closer look at each, using the latest scientific data. The data comes from highly professional scientists,
the very top men and women in their respective fields. To speak their language and work in their fields
as ordinary "grunt-level" workers requires a minimum of four
to six years of college, and many have their Masters and PhD's
with up to 10 years or more of post-graduate work in college. [the base level education requirements for a meteorologist
working for say NOAA can be found at http://www.opm.gov/qualifications/SEC-IV/B/GS1300/1340.htm
.]
This is an extremely important issue for everyone,
of every political persuasion. Html links to these scientific articles will
be given throughout this article wherever possible. This is a serious subject and I did not undertake
putting this article together on a whim. In my personal life I am a staunch conservative
in my political views. But
upon careful study I saw there is real scientific data to
prove that we actually are going into the initial stages of
serious global warming. Global warming goes beyond politics, and for
Christians it is a serious warning that time is very short. So at the end of this article we'll take a very
short look at some serious prophecies which predicted quite
a few of these side effects of global warming-some given by
God to Moses, and some given directly by Jesus. Let us begin. By the way, I always wanted to be an oceanographer
and marine biologist, but being a remedial reader prevented
me from pursuing the field, due to the heavy college requirements,
which my remedial reading level would have torpedoed. So I thoroughly enjoyed putting this article together. Being a bygone qualified Submarine sailor lent
some knowledge of the ocean and C02 scrubber systems to the
article as well. My
hat is off to all the wonderful and highly qualified scientists
whose works lent themselves to this article. You are unsung and highly dedicated heroes who are
attempting to warn this world of coming calamity in a very
professional but serious manner. Dennis Quaid and Ian Holm portrayed all of you and
your dedication to this selfless task [cf. The
Day After Tomorrow].
Chapter Headings
Introduction
I.Side Effects
of Global Warming
II.Mechanics of
Global Warming
III.The Carbon Cycle
IV.Oceanic Biology
101
V.Ocean & Atmosphere,
How They Interface
VI.Earth's Big Heat
Bucket, or Where the Missing BTU's Are Going
VII.The Earth's "Global
Heat Engine"
VIII.Earthquakes
IX.What Did Jesus
and the Old Testament Prophets Predict That Matches What We
Have Studied?
I. Side Effects
of Global Warming
Weather: Increased extreme weather patterns, increased
evaporation and destabilization of local climates.
Oceans: Sea level rise. Ocean surface temperature rise. Acidification. Shut down of thermo cline circulation.
Ecosystems: Ecosystem productivity hurt, decline of agriculture.
Environment: Water scarcity, deforestation, desertification
as a result of glacier retreats, and expansion of tropical
zone climate.
Health: Spread of diseases following climatic changes.
Projected Climate Changes that are already occurring: 1) Slowing of ocean circulation that moves
warm water to the North Atlantic, Iceland, the British Isles
and Europe. 2) Large
reductions in Greenland and West Antarctic Ice Sheets. 3) Accelerated global warming due to Carbon Cycle feedbacks
in the terrestrial biosphere, and, 4) the release of Terre
sphere carbon from permafrost regions and methane from hydrates
in coastal sediments in far northern latitudes.
Some significant negative side effects are already
beginning to show themselves, rise in sea levels, higher local
temperatures, and changes in rainfall patterns. Higher sea levels even now exacerbate coastal flooding
and lead to an increase in salinity of aquifers and estuaries
in countries with lower level landmasses, close to sea-level. Increase in temperature leads to increasing
precipitation, but with that comes more violent weather patterns. Worldwide, the proportion of hurricanes attaining
levels of Category 4 and 5 has risen from 20 percent in the
1970's to 35 percent in the 1990's. The World Meteorological Organization has suggested
a possible link between global warming and increasing extreme
weather events."Hurricanes, simulated under warmer, high-C02
conditions are more intense.Greenhouse gas-induced warming
may lead to increasing occurrence of highly destructive Category-5
storms." (http://www.gfdl.noaa.gov/reference/bibliography/2004/tk0401.pdf
)
"The hurricanes we are seeing are indeed a direct result
of climatic change" says Greg Holland, Director of the Mesoscale
& Microscale Meteorological Division at the National Center
For Atmospheric Research in Boulder, Colorado. He says that the wind and warmer water conditions that
fuel storms that form in the Caribbean are "increasingly due
to greenhouse gases.''
Increased evaporation: As the climate grows warmer, evaporation
increases. Heavier
rainfall in tropical latitudes (especially in Africa) and
desertification and/or shifting of weather patterns will become
more common. Example:
Stephen Mwakifwamba, National co-coordinator of the Centre
for Energy, Environment, Science and Technology for Tanzania
says climate change is happening already in Tanzania right
now. "In the past,
we had a drought about every ten years. Now we just don't know when they will come. They are more frequent, but then so are floods. The climate is less predictable. We might have floods in May or droughts every three
years.Water levels are decreasing every day. The rains come at the wrong time for farmers
and it is leading to many problems." ( http://www.guardian.co.uk/climatechange/story/0,12374,1517935,00.html)
Destabilization of local climates: "In the northern hemisphere the southern
part of the Arctic region has experienced a temperature rise
of 1 degree to 3 degrees Celsius over the last 50 years. Canada and Russia are experiencing initial melting
of permafrost. This may disrupt ecosystems and by increasing
bacterial activity in soil lead to these vast areas becoming
Carbon (CO2) sources instead of Carbon sinks ( http://www.arctic.noaa.gov/essay_romanovsky.html
) Similar melting of
permafrost in Western Siberia is also taking place, and the
melting of this permafrost is likely to lead to release of
large quantities methane-a major greenhouse gas. This will occur over decades, but is beginning right
now. ( http://www.newscientist.com/article.ns?id=mg18725124.500
)
Oceans: Increasing average global temperatures makes the water
in the oceans expand in volume. Coupled to this the additional water entering from
double the volume of normal ice-melt, the IPCC paper of 2001
says an increase of 1.5 to 4.5 degrees C is estimated to lead
to an increase in sea level from 8 inches to 12 feet during
the 21st century. From 300 years ago to the 19th century sea
levels remained nearly constant, rising only 0.1 to 0.2mm
per year. Since 1900
the rise rate has shifted to 1-2mm per year. And since 1992 satellite altimetry from TOPEX/Poseidon
indicates a rate of about 3mm per year.
(http://www.grida.no/climate/ipcc_tar/wg1/426.htm
)
Temperature rise: The temperature of the Antarctic Southern
Ocean rose by 0.17 degrees C (0.31 degrees F) between the
1950's and the 1980's, twice the rate of the world's oceans
as a whole. Warming, especially in the colder polar oceans,
reduces the ocean's ability to absorb CO2.
Temperatures are rising in the Gulf of Mexico.
As hurricanes cross the Warm Loop current coming up
from South America they can gain great strength in under one
day (i.e. Katrina and Rita in 2005) with water temperatures
above 85 degrees F promoting Category-5 storms. (I learned that temperatures of 95 degrees F
were reached in the Gulf of Mexico that year.) To view NOAA's buoy data for yourself from their National
Buoy Data Center (NBDC) for the Caribbean, which monitor ocean
surface temperatures click on http://www.ndbc.noaa.gov/maps/Florida.shtml
When the map comes
up, just click on the buoy number you want to access, and
it's data will come up on the screen.
Hurricanes were thought to be an entirely North Atlantic
phenomenon, but in April 2004 the first hurricane to form
south of the Equator hit Brazil with 144 km/h winds
Acidification: The world's oceans soak up much of the CO2
produced by living organisms, either as dissolved gas, or
in the skeletons of tiny marine creatures that fall to the
bottom to become chalk or limestone. Oceans currently absorb 1 metric ton of CO2 per person
per year. Estimates
are that the oceans have absorbed one half of all the CO2
generated by human activities since 1800 (120 billion tons). For all you nuke sub sailors, the earth's oceans
you're used to cruising under the surface of is the earths
giant CO2 scrubber system.Terrestrial plants do not absorb nearly as much CO2
as do the oceans. We'll
get into this more later. ( http://www.sciencemag.org/cgi/content/305/5682/367/DC1
)
CO2 becomes a weak carbonic acid (HCO3), and thus increases
of atmospheric CO2 since the 1800's has already lowered the
ocean's PH by 0.1 to near 8.2 on the scale of 1 to 14. ( http://news.bbc.co.uk/1/hi/sci/tech/4633681.stm
) Acidification could
destroy corals and other marine organisms with calcium carbonate
shells and skeletons, which will also contribute to slower
CO2 absorption resulting in further rise in atmospheric CO2. All these living oceanic organisms help "scrub" CO2
from the atmosphere, placing it safely locked away in the
form of CaCO3 skeletons and diatomic "plant matter" on the
ocean floor. From there
it compacts down to become chalk, and then eventually limestone. Under greater time compression it becomes marble. [see also http://www.sciencedaily.com/encyclopedia/Ocean_acidification#Acidification]
Shutdown of the thermo haline circulation: Desalinization due to the doubled volumes of ice-melt
and glacier speeds in Southern Greenland could cause a shutdown
of the Gulf Stream and/or the North Atlantic Drift current. Currently, over the past 30 years the Gulf Stream has
slowed by 30 percent, registering a 10 percent slowdown per
decade. (This is The Day After Tomorrow stuff, right in
front of our eyes!) Alterations
to the ocean currents due to increased freshwater inputs from
glacier melt, and the potential alterations to thermo haline
circulation of the world's oceans may impact fisheries upon
which humans also depend.
Ecosystems: Rising global temperatures are beginning to impact
ecosystems. Butterflies have shifted their ranges northward
by 200 km in Europe and North America. In the Arctic the waters of Hudson Bay are ice-free
for 3 weeks longer than they were 30 years ago. That's a one week per decade shift!
Two 2002 studies found changes in range or seasonal
behavior by plant and animal species, with four out of five
changing their ranges toward the poles or higher altitudes-creating
"refugee species". Frogs
breeding, flowers blossoming, birds migrating 2.3 days earlier
each decade and moving toward the poles by 6.1 km per decade! (6.9 days in 3 decades or 1 week shift in 30
years!)
Forests face an increased risk of forest fires. Boreal forest burned in North America was 10,000 square
km annually (2.5 million acres). It has now, since 1970 almost tripled to 28,000 square
km (7 million acres) annually. ( http://www.usgcrp.gov/usgcrp/nacc/education/alaska/ak-edu-5.htm
)
Glacier retreat: Since 1980 glacier retreat has become increasingly
rapid, so much so that it has threatened the existence of
many of the glaciers of the world. This process has increased markedly since 1995. Want to get a little scared? Click on this link ( http://www.nichols.edu/departments/glacier/
). Currently glacier
retreat and mass balance losses have been increasing in the
Andes, Alps, Himalayas, Rocky Mountains and North Cascades. The total surface area of glaciers worldwide has decreased
by 50 percent since the end of the 19th century. ( http://www.munichre.com/pages/03/georisks/geo_climate/glaciers/glaciers_en.aspx
) Effects of increased
glacier melt and retreat could become catastrophic to mankind.
Increase in annual variation in water flows in rivers
fed by glacier runoff will take place. Glacier runoff declines as glaciers decrease in size,
and this is already observable in several regions. The situation will become even more dramatic in the
earth's arid zones. For example, 70 percent of the water in the
Ganges comes from Nepalese rivers which are mostly fed by
melt-water. Nearly all of the water in Lake Aral comes from
glaciers of the Tien Shan and Pamir mountains. Many glaciers are being lost to melting, raising
concerns about future local water resources in these glacierized
areas. As runoff declines in summer as these glaciers
decrease in size, river flow will become flashy, with extremely
low water levels in summer, where they were sufficient before. What a glacier does: They retain water in high precipitation years,
as their snow-cover accumulates on them, protecting the ice
from melting. In warmer
and drier years glaciers offset lower precipitation by their
higher melt-water input to lakes and rivers. But if the glaciers sufficiently and steadily shrink
or disappear, this balance goes out the window. The continual shrinking of mountain glaciers in Western
North America, Franz-Josef Land, Asia, the Alps, Indonesia
and Africa, as well as the tropical and sub-tropical regions
of South America is raising serious concerns about local water
resources in these glacierized areas. Lewis Glacier is only one out of 47 North Cascade glaciers
which are all retreating. These glaciers are very important water sources
to their respective human populations, and they only comprise
1 percent of all the ice-sheets by volume.
[this information adapted from http://en.wikipedia.org/wiki/Effects_of_global_warming
along with other articles from other sources, listed as they
are used] That was an overview of current trends.
Let's Take A
Closer Look At What's Occurring
Is Warming Causing Alaska Meltdow. "Alaska's
glaciers are retreating, reports glacial geologist Bruce Molnia. Significant glacier retreat, thinning, stagnation,
or a combination of these changes characterize all 11 mountain
ranges and three island areas that presently support glaciers. Alaska is home to around 2,000 valley glaciers,
including nearly 700 that are named. Fewer than 20 are advancing."We are certainly experiencing
a climatic change that's having a pronounced effect in some
areas of the world. But we don't know what component of the change
is natural versus what's human induced."The popular perception
of global warming is the entire Earth is warming everywhere. The record doesn't show that" said Molnia. Alaska's temperature changes are far more dramatic
than in other regions of the world, and the retreat of Alaska's
glaciers is quite significant, concludes Molnia.The glaciers
in Alaska, Chile, Indonesia, New Zealand, and Iran are all
temperate glaciers. Temperate
or "warm" glaciers are always very close to melting. They tend to lose mass in the summer heat, but gain
it from winter precipitation. Nearly all of the world's temperate
glaciers are retreating, thinning, or stagnating."
[Emphasis mine] (National
Geographic News, December 18, 2001)
Alaskan Glacier Melting Faster: "The researchers say the resulting
melt waters are sufficiently large to drive up global sea
levels by 0.14mm per year [this from only the retreating Alaskan
glaciers, not taking into account Greenland or West Antarctica]. The study by Dr. Keith Echelmeyer, of the University
of Alaska Fairbanks Geophysical Institute, and colleagues
used laser altimetry to measure the volume changes of 67 Alaskan
glaciers from the mid-1950's to the mid-1990's. Their work, published in the journal Science,
adds to the growing evidence that the level of recent glacier
wastage-from polar regions to the tropics-has been underestimated."What
we see over the last 50 years is that they have thinned quite
substantially and over the last 10 years there has been an
acceleration." "The
climate is changing and this is affecting the glaciers-and
they are being a good indicator of that," he said.Glaciers
in Alaska and neighbouring Canada cover 90 thousand square
kilometers, or approximately 13 percent of the mountain glacier
area on Earth. Dr.
Echelmeyer's team surveyed the volume and area changes of
part of this region from an aircraft equipped with a laser
altimetry system. The researchers measured the volume loss by
checking glacier elevation and volume data on US Geological
Survey maps from the 1950s. "Most glaciers have thinned several hundred feet at
low elevations in the last 40 years and about 60 feet at higher
elevations," Dr. Echelmeyer said. The team calculated that Alaskan glaciers are responsible
for at least 9 percent of the global sea-level rise during
the past century, and Alaska's glaciers raise the level of
Earth's oceans by more than one-tenth of a millimetre each
year. The study fits
with a review of data by Professor Meier and Mark Dyurgerov,
of the University of Colorado at Boulder, US. They said glacier wastage had been seriously underestimated
by the UN's Intergovernmental Panel on Climate Change (IPCC).One
of the reasons for this, they said, was the IPCC had not had
access to the latest Alaskan data. "For the first time we have some hard data from
these glaciers which we have suspected, but didn't know for
sure, are major contributors to sea level change caused by
glacier melt," Professor Meier said after the Fairbanks study
was published. The
contribution from Alaska's glaciers to the worldwide sea level
rise "is even more than what we expected," he added." (BBC News, July 18, 2002)
Tibetan
Glaciers Melting at a Rapid Rate: "BEIJING-Glaciers in western China's Qinghal-Tibet
plateau, known as the "roof of the world", are melting at
a rate 7 percent annually due to global warming, the country's
official Zinhua News Agency said.Statistics from the Tibet
weather bureau show that average temperatures in Tibet have
risen by 0.9 degrees Celsius (2 degrees Fahrenheit) since
the 1980's, Xinhua reported, quoting Han Yongxiang of the
National Meteorological Bureau. The glaciers in the Qinghai-Tibet plateau account for
47 percent of China's total glacier coverage.The melting glaciers will eventually lead to drought, more desertification
and an increase in the number of sandstorms, Xinhua
quoted researcher Dong Guangrong at the Chinese Academy of
Sciences as saying." (Associated Press, May 3, 2006)
More Impacts of Glacier Retreat: In areas that are heavily dependent
on water runoff from glaciers that melt during summer months,
a continuation of the current retreat will eventually deplete
the glacial ice and substantially reduce or eliminate runoff
water supplies. A reduction of runoff will affect the ability
to irrigate crops and will reduce summer stream flows necessary
to keep dams and reservoirs replenished. This situation is particularly acute for irrigation
in South America which has numerous artificial lakes which
are almost entirely filled by glacial melt (BBC)
MEXICO CITY-Droughts, floods, changing rain patterns and rising sea
levels are threatening development in the world's poorest
countries, experts and aid workers said Monday at an international
water forum. Regions including Africa, South Asia-home to
most of the 1.1 billion people who live without clean water-will
be among the hardest hit by changing weather patterns, experts
at the 4th World Water Forum said. They blamed the threats largely on changes in the global
climate. "Drought will worsen. We will see deforestation of the environment,"
said Michel Jarraud, Secretary-General of the World Meteorological
Organization. "The
least developed countries don't have the resources to mitigate
the impact.".Greenhouse gases such as CO2 have been increasing
in the atmosphere since the Industrial Revolution, raising
fears they are warming the planet's climate by trapping heat
from the sun.Gana Unnayan Sangstha, an aid worker who helps
install community water systems in Bangladesh's poor coastal
Province of Satkahira, has already seen the effects of global
warming. "Bangladesh is the lowest country in the world. There are salinity intrusions into larger areas due
to climate change, and a rise in sea-water levels," Unnayan
Sangstha said. When
salt gets into ground water-such as in the wells used in many
Bangladesh projects-it becomes useless for drinking or irrigation. Increasing salinity is also a problem in areas around
Karachi, Pakistan, where Tanver Arif works on a rural-aid
project aimed at building ponds that collect water in an arid
environment. "Since
about two decades ago, there is some climate change, and the
rains are moving to the east," Arif said. Joe Madiath, of the India-based rural development organization
Gram Viras, said climate change is devastating Orissa, one
of the country's poorest states."Floods, typhoons-you name
it, we have it.while the amount of rainfall remains constant
from previous years, it comes all at once, a problem he said
is getting worse. Jamie Pittock, Executive Director of the
World Wildlife Fund, said major rivers could be affected by
global warming. "Rivers like the Indus and Ganges could see
reduced flow," he said. "At
the moment they have a steady base flow from melting glaciers,
but when those glacier flows are reduced [as they currently
are becoming], the rivers will become more flashy, with greater
flows in the wet season and lower flows in the dry season."."That
will be devastating, not only for people, but for the environment,"
he added. [Associated
Press]
The Polar Regions-'Climatic "Canary"
in the Mineshaft'
Polar ice is made up of two distinct types which are radically different
from each other, based upon how they are created. The first is sea-ice, which floats upon the
surface of the polar ocean surfaces and is formed from salt-water
or sea-water freezing. Of
course when it snows on sea-ice, that snow will compact down
into a growing layer of fresh-water ice on top of sea-ice,
especially in the northern polar regions that stay below freezing
in both summer and winter, or do not suffer complete melt-down
over the summer. Global
sea-ice covers 25 million square kilometers of the northern
polar regions, or roughly the size of the North American Continent.
Ice sheets and glaciers: Ice sheets and glaciers cover 15 million
square kilometers, or about 10 percent of the Earth's land
surface area. Don't forget, ice sheets reside on land (but
can flow via glaciers into the sea). They are created by falling snow, which is then compacted
down into ice sheets. These
ice sheets form into frozen rivers, which most often flow
into the sea, but sometimes they flow into major river systems
or lakes (both natural or man-made).
Sea and Land Ice as Climate Regulators: As with snow, sea and land ice sheets and glaciers
reflect 90 percent of the sun's radiated energy back into
outer-space and absorb only 10 percent of it. Oceans, on the other hand absorb a full 90 percent
of the sun's radiant energy and reflect back a mere 10 percent
of it into outer-space. If
say global cooling were to start to occur, more sea-ice would
form and ice sheets and glaciers would extend over land and
open ocean, providing a positive feedback for global cooling,
bringing on an acceleration of global cooling. In like manner, if conditions continue with the global
warming trend, and sea-ice and ice shelves continue to shrink,
a positive feedback for increased global warming will be triggered
as increased square mileage of ocean are exposed to sunlight
(absorbing 90 percent of the sun's radiant energy). [ see http://earthobservatory.nasa.gov/Library/PolarIce/
] "The Greenland ice
sheet is warmer than the Antarctic ice sheet, thus global
warming could produce serious melting on Greenland while having
less effect in the Antarctic. In the Antarctic, temperatures are far enough
below freezing that even with some global warming, temperatures
would remain sufficiently cold to prevent surface melting." [ http://earthobservatory.nasa.gov/Library/PolarIce/polar_ice2.html] But where ice sheets extend outward to the ocean,
the ice tends to move out over the ocean forming "ice shelves". The big concern with the current global warming
trend is this, the sea-water under these "ice shelves" (Larsen
A, B, C, and the Ross Sea, etc) would grow warmer, causing
these shelves to break up more readily (which has started
to occur [Larsen B], thus releasing more inland ice in an
irreversible process (i.e. speed up the flow of major Antarctic
inland ice sheets). The
positive feedback scenario isn't endless though, because with
increased ocean surfaces comes increased evaporation, bringing
back the ice, but only after decades of damaging global warming
side-effects, since formation of major ice sheets and then
ice-shelves takes multiple decades, whereas, we've witnessed
the breakup of some of these ice shelves in very short periods
of time.
Sea Ice Melting: Sea-ice melting
does not effect sea level. But sea-ice-with its very high solar reflective properties
and insulation properties for the ocean under them-is an important
part of the heat exchange regulatory system of the Earth. Right now sea-ice in the northern polar regions is
retreating, as will be seen in a few pages of this article. But sea-ice is known to change both seasonally and
interannually, so it bears watching to see if its shrinkage
continues over the next three or four years, indicating a
more serious trend in global warming.
A look at what's happening:99
percent of all glacier ice is contained in the great ice sheets
of the polar and sub-polar regions of Antarctica and Greenland. These continuous continental-size ice-sheets
are 3km or 1.8 miles or more thick. They cap the polar and sub-polar land masses. These great ice rivers flowing from huge frozen lakes
transport ice from the margins of the ice-sheet to the ocean. In periods of relative climatic stability the amount
of snow precipitation inflow matches the glacier out-flow
into the oceans. The oceanic rise in sea level has been extremely
small over the centuries, but has recently increased dramatically. As the planet enters a period of steady global warming,
as it is doing, let's see what is happening with these huge
glaciers. Glacier retreat
has been observed in these outlet glaciers, resulting in an
increase of their flow-rates. In Greenland the period since 2000 has brought retreat
in three very large glaciers that used to be stable. They jointly drain more than 16 percent of the Greenland
Ice Sheet. Satellite
images and aerial photos from the 1950's through the 1970's
show the front of the glacier as being stable. "But in 2001 it began retreating rapidly, at a rate
of 7.2 km between 2001 and 2005. Jakobshavn Isbrae in Western Greenland is the fastest
moving glacier in the world. It had been moving continuously at 24m a day
(65' a day) with a stable terminus since 1950. In 2002 the 12km long floating terminus entered a phase
of rapid retreat. The
ice front started to break up and the floating terminus disintegrated,
accelerating to a retreat rate of over 30m (98') per day!" The rate of retreat of Kangerdlugssuaq Glacier is even
larger. Portions of the main trunk that were flowing
at 15m (49') a day in 1998-2001 were flowing at 40m (131')
a day in the summer of 2005." ( http://www.agu.org/meetings/fm05/fm05-sessions/fm05_C41A.html
)
Glacier retreat is also apparent on two important outlet
glaciers of the West Antarctic Ice Sheet. Pine Island Glacier, which flows into the Amundsen
Sea thinned 3.5 +/- 0.9m (11.5 +/- 3 feet) per year and retreated
5km in 3.8 years. The
terminus of this glacier is a floating ice shelf and the point
at which it is afloat is retreating 1.2km a year. This glacier drains a substantial portion of the West
Antarctic Ice Sheet ( http://www.sciencemag.org/cgi/content/abstract/281/5376/549
). This same pattern
of thinning is evident on the neighboring Thwaites Glacier.
January 20, 1999: "There is a large range
of uncertainty in trying to predict how much the ice sheets
will contribute to sea level rise over the next century as
Earth's climate warms. Reports
published by an international government panel estimate a
rise in sea level by 2100 that varies in range from 20 cm
(about 8 inches), which is minimal and the present rate, to
96 cm (about 36 inches, or 3 feet). The West Antarctic Ice Sheet is believed to be the
most likely source of this rise, but there is still debate
concerning the ice sheet's stability and those mechanisms
that could cause the ice sheet to melt. If this extreme prediction comes true, Anderson
says, Texas's Galveston Island would not survive, South Louisiana
would be flooded, and Bangladesh would be under water. To date, research has focused on the Ross Sea, where
50 percent of ice sheet drainage into the ocean occurs..."Undermelting
now seems to take on greater importance." (Sciencedaily.com)
April 9, 1999: "Two ice shelves on the Antarctic Peninsula, the Larsen
B and Wilkens, are in "full retreat" and have lost nearly
3,000 square kilometers of their total area in the last year
according to scientists in Colorado and the UK. On the opposite side of the peninsula from the Larsen
B Ice Shelf, the Wilkens Ice Shelf retreated nearly 1,100
square kilometers in early March of last year according to
Ted Scambos, Research Associate at Boulder's National Snow
and Ice Data Center (NSIDC). "The radar images showed a large area of completely
shattered ice, indicating an ice front 35 kilometers back
from its previous extent. The sudden appearance of thousands of small icebergs
suggests that the shelves are essentially broken up in place
and flushed out by storms or currents afterward" Scambos said. (Sciencedaily.com)
January 20, 2001: "Warmer surface temperatures during summers can
cause more ice on Antarctica ice shelves to melt into standing
water ponds, then leak into cracks and increase the odds of
collapse, according to a new study published by an American
team of scientists.The result [of this study] implies that
other ice shelves are closer to the breaking point than we
previously thought," said Scambos. "The shelf retreats that have occurred so far have
had few consequences for sea-level rise, but breakups in some
other areas like the Ross Ice Shelf could lead to increases
in ice flow off the Antarctic and cause sea level to rise."."The
process can be expected to be more widespread if Antarctic
summer temperatures continue to increase."."Warmer summer
temperatures on the much larger Ross Ice Shelf in Antarctica
could have severe repercussions because the ice shelf is part
of the "braking system" for some very large glaciers," Scambos
said. "If we begin
to get significant water ponding there, and the shelf is eventually
destroyed, we would likely have ice pouring off the Antarctic
at a much faster rate. That would increase sea level significantly." "We need to monitor the summertime temperatures to
see what the future holds for these ice sheets," said Hulbe. "While some areas of the Antarctic have warmed by as
much as 4.5 degrees Fahrenheit in the past 50 years, few records
have been kept of seasonal temperatures over ice shelves,"
she said. (Sciencedaily.com)
December 17, 2001: "Global mean temperatures have risen one degree
Fahrenheit over the past 100 years, with more than half of
the increase occurring in the last 25 years, according to
University of Colorado at Boulder Senior Researcher Richard
Armstrong. "As slight
as that may seem, it's enough to make a difference.Now, long-term
monitoring of a series of cold region, or cryospheric, parameters
shows that for several decades the amounts of snow and ice
around the world have been decreasing.In the world of climate
change, trends are most readily observed in the Earth's cold
regions, where the sensitivity of ice and snow to temperature
changes serves as an early indicator of even relatively small
differences," he said. "Today's
receding and thinning sea ice, mountain glacier mass losses,
decreasing snow extent, melting permafrost and rising sea
level are all consistent with warming.Examination of springtime
ice thickness in the Arctic Ocean indicates that the mean
ice thickness decreased by 1.5 meters between the mid-1980's
and early 1990's.At low altitudes, glacial changes are pronounced,
uncontested and solid evidence of climate warming," said Eric
Rignot, a researcher at the Radar Science and Engineering
Section of NASA's Jet Propulsion Laboratory."My study shows
that a number of areas previously believed to be gaining mass
in the Antarctic are in fact close to being balanced or even
losing mass. The only
areas which stands out as clearly out of balance is the Amundsen
Sea sector of Antarctica
drained by the Pine Island and Thwaites glaciers." "We know that the retreat of the Pine Island, Thwaites
and Smith glaciers was due to a widespread thinning of ice
that extended from their termini to over 200 kilometers inland,"
said Andrew Shepherd of the Centre for Polar Observation and
Modeling at University College London. These glaciers are the principal ice drainage channels
for the Amundsen Sea sector of the West Antarctica Ice Sheet. According to Shepherd, between 1991 and 2001 the Pine
Island , Thwaites and Smith glaciers thinned by more than
15, 25 and 45 meters respectively where they leave the continent
and begin to float, losing a total of 157 cubic kilometers
of ice to the ocean." ( http://www.sciencedaily.com/releases/2001/12/011210163124.htm
)
Larsen Ice Shelf: "The Larsen Ice Shelf is a long, fringing ice
shelf in the northwest part of the Weddell Sea, extending
along the east coast of the Antarctic Peninsula from Cape
Longing to the area just southward of Hearst Island.the Larsen
Ice Shelf is a series of three shelves that occupy (or
occupied) distinct embayments along the coast. From north to south, the three segments are called
Larsen A (the smallest), Larsen B, and Larsen C (the largest). The Larsen A ice shelf disintegrated in January of 1995. The Larsen B ice shelf disintegrated in February
of 2002. The Larsen
C ice shelf appears to be stable. The Larsen disintegration events were unusual. Typically,
ice shelves lose mass by iceberg calving and by melting at
their upper and lower surfaces. The disintegration events are linked to the
ongoing climate warming in the Antarctic Peninsula, about
0.5 degrees C per decade since the late 1940's (almost certainly
a result of global warming)." (Sciencedaily.com)
Larsen B ice shelf: "During January 31st to March 7th,
2002 the Larsen B ice shelf collapsed and broke up. 3250 square kilometers of ice 200 meters thick
broke off. The shelf
had previously been stable for 10,000 years.according to Queen's
University researchers." (Sciencedaily.com)
September 2, 2002: NASA Study Finds Rapid Changes in Earth's Polar Ice
Sheets: "Recent airborne measurements and a new review
of space-based measurements of the thickness of Earth's polar
ice sheets concludes they are changing much more rapidly than
previously believed, with unknown consequences for global
sea levels and Earth's climate.Large sectors of ice in southeast
Greenland, the Amundsen Sea Embayment in West Antarctica and
the Antarctic Peninsula are changing rapidly by processes
not yet well understood, said researchers Dr. Eric Rignot
of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and
Dr. Robert Thomas of EG&G Services at NASA's Wallops Flight
Facility, Wallops Island, Va. .Earth's polar ice sheets are changing over
relatively short time scales, that is, decades versus thousands
of years," Rignot said.Rignot said understanding how polar
ice sheets evolve is vital to society. "The Antarctic and Greenland's ice sheets together
hold enough ice to raise sea level by 70 meters (230 feet),"
he said. Even a small
imbalance between snowfall and discharge of ice and melt water
from ice sheets into the ocean could be a major contributor
to the current sea level rise rate of 1.8 millimeters (0.07
inches) a year and impact ocean circulation and climate. During past periods of rapid deglaciation, ice
sheet melting raised sea level orders of magnitude faster
than today. This is the real threat of the ice sheets.The
review reports Greenland's ice sheet is losing 50 cubic kilometers
(12 cubic miles) of mass a year due to rapid thinning near
its coasts. That's enough to raise sea level 0.13 millimeters
annually. "Rapid coastal
thinning cannot be explained by a few warm summers and is
attributed to a dynamic ice sheet response," Rignot said. "A possible contributor to the observed trend is increased
lubrication from additional surface melt water reaching glacier
beds through crevasses and moulins." (taken from http://www.jpl.nasa.gov/releases/2002/release_2002_168.html
and
September 24, 2004: Scientists Report Increased Thinning Of West Antarctic
Glaciers: "Glaciers in West Antarctica are shrinking at
a rate substantially higher than was observed in the 1990s. They are losing 60 percent more ice into the
Amundsen Sea than they accumulate from inland snowfall.Dr.
Bob Thomas commented that as the glaciers flow to the ocean,
they become afloat to form ice shelves. "The ice shelves act like a cork and slow down the
flow of the glacier," Thomas said. "Ice shelves in the Amundsen Sea appear to be
thinning, offering less resistance to their tributary glaciers. Our measurements show an increase in glacier
thinning rates that affect not only the mouth of the glacier,
but also 100 kilometers (60 miles) to 300 kilometers (190
miles) inland." Thomas said.Thomas pointed out that the observed
increases in velocities and thinning rates apply only to a
short period of time, so it is too early to tell if the accelerated
thinning is part of a natural cycle or is a sign of a longer-term
change. "Continued observation is important," he said. "The rates of glacier change remain relatively small
at present," said Dr. Rignot. "But the potential exists for
these glaciers to increase global sea level by more than one
meter. The time scale over which this will take place
depends on how much faster the glaciers can flow, which we
do not know at present" (
http://www.sciencedaily.com/releases/2004/09/040924090900.htm
)
April 25, 2005: Antarctic Peninsula Glaciers in Widespread Retreat: "The
first comprehensive study of glaciers around the coast of
the Antarctic Peninsula reveals the real impact of recent
climate change. Results from the study by researchers at British
Antarctic Survey (BAS) and U.S. Geological Survey (USGS).show
that over the past 50 years 87 percent of 244 glaciers studied
have retreated, and the average retreat rates have accelerated.Fifty
years ago, most of the glaciers we looked at were slowly growing
in length but since then this pattern has reversed. In the last 5 years the majority were actually shrinking
rapidly.On average the glaciers we studied retreated by 50
meters per year in the last five years, faster than at any
other time in the last fifty years.It's the change from advance
to retreat that suggest warming is the key cause.These glacier
retreat patterns combined with dramatic ice shelf break-ups
leave us in no doubt that the Antarctic Peninsula ice sheet
is extremely sensitive to recent warming" says BAS Glaciologist
Dr. David Vaughan. ( http://www.sciencedaily.com/releases/2005/04/050425110258.htm
)
December 20, 2005: NASA's Grace Finds Greenland Melting Faster: "In the first direct comprehensive mass
survey of he entire Greenland ice sheet, scientists using
data from the NASA/German Aerospace Center Gravity Recovery
and Climate experiment (GRACE) have measured a significant
decrease in the mass of the Greenland ice cap.In an update
to findings published in the journal Geophysical Research
Letters, a team led by Dr. Isabella Velicogna of the University
of Colorado, Boulder, found that Greenland's ice sheet decreased
by 162 (plus or minus 22) cubic kilometers a year between
2002 and 2005. This
is higher than all previously published estimates, and it
represents a change of about 0.4 millimeters (0.16 inches)
per year to global sea level rise. "Greenland hosts the largest reservoir of freshwater
in the northern hemisphere, and any substantial changes in
the mass of its ice sheet will affect global sea level, ocean
circulation and climate," said Velicogna. "These results demonstrate Grace's ability to measure
monthly changes for an entire ice sheet-a breakthrough in
our ability to monitor such changes." [see http://www.jpl.nasa.gov/news/news.cfm?release=2005-176
]
March 2, 2006: "Antarctic Ice Sheet Losing Mass, Says University of Colorado
Study. University of Colorado at Boulder researchers have
used data from a pair of NASA satellites orbiting Earth to
determine that the Antarctic ice sheet, which harbors 90 percent
of Earth's ice, has lost significant mass in recent years. The team used measurements taken with the Gravity Recovery
and Climate Experiment, or GRACE, to conclude the Antarctica
is losing up to 36 cubic miles of ice, or 152 cubic kilometers,
annually."This is the first study to indicate the total mass
balance of the Antarctic ice sheet is in significant decline,"
said Isabella Velicogna of CU-Boulder's Cooperative Institute
for Research in Environmental Sciences, chief author of the
new study.The most recent Intergovernmental Panel on Climate
Change assessment, completed in 2001, predicted the Antarctic
ice sheet would gain mass in the 21st century due
to increased precipitation in a warming climate. But the new study signals a reduction in the
continent's total ice mass, with the bulk of loss occurring
in the West Antarctic ice sheet, said Velicogna.Launched in
2002 by NASA and Germany, the two GRACE satellites whip around
Earth 16 times a day at an altitude of 310 miles, sensing
subtle variations in Earth's mass and gravitational pull. Separated by 137 miles at all times, the satellites
measure changes in Earth's gravity caused by regional changes
in the planet's mass, including such things as ice sheets,
oceans and water stored in the soil and in underground aquifers.A
study spearheaded by CIRES researchers at CU-Boulder and published
in September 2004 concluded that glaciers on the Antarctic
Peninsula-which juts north from the West Antarctic ice sheet
toward South America-sped up dramatically following the collapse
of Larsen B ice shelf in 2002. Ice shelves on the peninsula-which has warmed by an
average of 4.5 degrees Fahrenheit in the past 60 years-have
decreased by more than 5,200 square miles in the past three
decades (30 years). The
Earth's fifth largest continent, Antarctica is twice as large
as Australia and contains 70 percent of Earth's fresh water
resources. The ice
sheet, which covers about 98 percent of the continent has
an average thickness of about 6,500 feet. Floating ice shelves constitute about 11 percent of
the continent. The melting of the West Antarctic ice sheet
alone-which is about eight times smaller in volume than the
East Antarctic ice sheet-would raise global sea levels by
more than 20 feet, according to researchers from the British
Antarctic Survey [BAS]."( http://www.sciencedaily.com/releases/2006/03/060302180504.htm
)
March 30, 2006: "Rapid Temperature Increases
Above the Antarctic:A new analysis of weather balloon observations
from the last 30 years reveals that the Antarctic has the
same 'global warming' signatures as that seen across the whole
Earth, but is three times larger than that observed globally. The results by scientists from the British Antarctic
Survey (BAS) are reported this week in Science. Although the rapid
surface warming in the Antarctic Peninsula region has been
known for some time, this study has produced the first indications
of broad-scale climate change across the whole Antarctic continent. Lead author Dr. John Turner of the British Antarctic
Survey says, "The warming above the Antarctic could have implications
for snowfall across the Antarctic and sea level rise. Current climate model simulations don't reproduce the
observed warming, pointing to weaknesses in their ability
to represent the Antarctic climate system. Our next step is to improve the models.Analysis
of the radiosonde data showed a winter season warming throughout
the troposphere, which extends up to about 8km, and cooling
in the stratosphere above. The largest warming of almost three quarters of a degree
Centigrade per decade was found close to 5km above the surface. This is over three times the rate of warming observed
for the world as a whole. The warming has occurred across the whole of
the Antarctic and is apparent in the balloon data from Amundsen-Scott
Station at the South Pole to the many stations along the coast
of East Antarctica.Data shows the atmosphere in recent decades
has in fact warmed most some 4-5km above the surface, with
the stratosphere cooling above. There is increasing evidence that levels of
greenhouse gases have provided a blanket above the Earth trapping
heat at lower levels and giving cooling in the layers above. Air temperatures in the Antarctic region have risen
by over 2.5 degrees C in the last 50 years, about 5 times
faster than the global mean rate." ( http://www.sciencedaily.com/releases/2006/03/060330181319.htm
)
Dwindling Arctic Ice: According to the Canadian Ice Service, "the
amount of ice in Canada's eastern Arctic Archipelago decreased
by 15 percent between 1969 and 2004" "In parts of the Western Arctic the ice has receded
by 36 percent ( http://www.washingtontimes.com/specialreport/20050612-123835-3711r.htm
)".
2002: "In 2002, a series of
scientific studies pointed to dramatic changes in Arctic sea
ice. Sea ice that survives the summer remains year
round-called perennial sea ice-is melting at the alarming
rate of 9 percent per decade, according to a study by NASA
Goddard Space Flight Center senior researcher Josefino Comiso. The extent of Arctic sea ice at summer's end reached
a record low in 2002, reported NASA-funded researchers at
the University of Colorado's National Snow and Ice Data Center,
in Boulder.Most of the Arctic warmed significantly in the
1990s compared to the 1980s.The seasons when sea ice melts,
between early spring and late fall, have gotten longer and
warmer each decade. Arctic regions within North America have warmed
more per decade than other Arctic areas, data taken from satellites
between 1981 and 2001 shows. Such shifts in the Arctic are likely early indications
of a global climate in a state of flux. "People talk about global warming, and the Artic really
is the best place to detect global warming because the effects
are amplified there," Cosimo says. [ http://earthobservatory.nasa.gov/Study/ArcticIce/
and http://www.earthobservatory.nasa.gov/Study/ArcticIce/arctic_ice2.html
]
Walrus Calves Stranded by Melting Sea Ice: "Scientists have reported
an unprecedented number of unaccompanied and possibly abandoned
walrus calves in the Arctic Ocean, where melting sea ice may
be forcing mothers to abandon their pups as the mothers follow
the rapidly retreating ice edge north. Nine lone walrus calves were reported swimming
in deep waters far from shore by researchers aboard the U.S.
Coast Guard icebreaker Healy
during a cruise in the Canada Basin in the summer of 2004. Unable to forage for themselves, the calves
were likely to drown or starve, the scientists said.The sightings
suggest that increased polar warming may lead to decreases
in the walrus population. "We were on station for 24 hours, and the calves
would be swimming around us crying. We couldn't rescue them," said Carin Ashjian, a biologist
at Woods Hole Oceanographic Institution and a member of the
research team. The researchers found evidence of warmer ocean
temperatures that may have rapidly melted seasonal sea ice
over the shallow continental shelf where the walruses dive
to feed on bottom-dwelling animals such as clams and crabs. Walrus need the ice to rest themselves and to leave
the pups to rest while the mothers feed. Ice remained over very deep water. "If walruses and other ice-associated marine mammals
cannot adapt to caring for their young in shallow waters without
sea-ice available as a resting platform between dives to the
sea floor, a significant decline of this species could occur,"
the research team wrote. The
lead author of the study is Lee W. Cooper, a biologist at
the University of Tennessee.The researchers measured a mass
of water as warm as 44 degrees F (7 degrees C) moving onto
parts of the shelf from the Bering Sea to the south in 2004.
The warm water intrusion was more than six degrees higher
than temperatures for the same time and location in 2002. The warmer water apparently caused seasonal sea ice
to melt rapidly over the shallow continental shelf and retreat
to deep water over the Arctic Ocean basins, where the water
remained colder. In
the areas where ice remained, the bottom is up to 3,000 meters
(about 9,000 feet) deep, too deep for even adult walrus to
dive to feed." (excerpted
from "News Release,
Woods Hole Oceanographic
Institution,
April 13, 2006. http://www.whoi.edu/mr/pr.do?id=12209
)
November 8, 2004, New Scientific Consensus: Artic is Warming Rapidly. This is according to a paper given by the Arctic
Climate Impact Assessment, in Reykjavik, Iceland. The 140 page paper basically shows in great detail
that the Arctic is warming much faster than previously known
or realized, at nearly twice the rate as the rest of the planet,
and increasing greenhouse gases from human activities are
projected to make it warmer still.At least half the summer
sea ice sheet in the Artic is projected to melt by the end
of this century, along with a significant portion of the Greenland
Ice Sheet. The region
is projected to warm an additional 4-7 degrees C (7 to 13
F) by 2100.The assessment's projections are based on a moderate estimate of future emissions
of carbon dioxide and other greenhouse gases.Says Robert Corell,
chair of the ACIA, "The Arctic is experiencing some of the
most rapid and severe climate change on earth. The impacts of climate change on the region and the
globe are projected to increase substantially in the years
to come.".Warming over Greenland is projected to lead to substantial
melting of the Greenland Ice Sheet, contributing to global sea-level
rise at increasing rates.Over the long term, Greenland
contains enough melt water to eventually raise sea level by
about 7 meters (about 23 feet).Over the next 100 years, climate change is
expected to accelerate, contributing to major physical ecological,
social, and economic changes, and Assessment has documented that many of these changes
have already begun. (Sciencedaily.com) [see http://www.acia.uaf.edu ]
February 17, 2006, SAINT LOUIS-Greenland's southern glaciers have
accelerated their march to the Atlantic Ocean over the past
decade and now contribute more to the global rise of sea levels
than previously estimated, researchers say. Those faster-moving glaciers, along with increased
melting, could account for nearly 17 percent of he estimated
one-tenth of an inch annual rise in global sea levels, or
twice what was previously believed, said Eric Rignot of NASA's Jet Propulsion Laboratory in Pasadena, Calif.That stepped-up flow accounted for about two-thirds
of the net 54 cubic miles of ice Greenland lost in 2005. That compares with 22 cubic miles reported in
1996, Rignot said. Rignot
and his study co-author Pannir Kanagaratnam of the University
of Kansas, said their report is the first to include measurements
of recent changes in glacier velocity in the estimates of
how much ice most of Greenland is losing.If warmer temperatures
spread to northern Greenland, the glaciers there too should
pick up their pace, Rignot and Kanagaratnam wrote."
Dr. Eric Rignot is a research scientist for the Jet
Propulsion Laboratory's Radar Science and Engineering Section. His research interests are in geoscience applications
of radar interferometry and polarimetry. He is a principal investigator on several NASA-funded
projects to study the mass balance of the Greenland and Antarctic
ice sheets using radar interferometry combined with other
methods; tiny interactions of ice shelves with the ocean;
and the dynamic retreat of Patagonian glaciers. He received the JPL Lew Allen Director's Award for
Excellence in 1998. Dr. Rignot is a member of AGU and of the International
Glaciological Society. (NASA
Quest> Archives::)
Expected current melt rates: Combined
current glacial melt coupled to thermal expansion is expected
to cause a 3.2 foot rise in ocean levels during the 21st
century. From 1880 to the year 2000 the oceans have risen
by 20cm, or about 8 inches. They were pretty much steady before then
Quotes from "Time on the Shelf" by David Herring: "When Bindshadler and his colleagues first
visited Antarctica in 1980, they brought with them the traditional
wisdom gleaned by generations of explorers and glaciologists
before them that large ice sheets are slow, plodding things
that wax and wane on cycles ranging from centuries to millennia. But the evidence they painstakingly pieced together
over the course of 13 expeditions to Antarctica over 25 years
suggests that the perceived permanence of Antarctica's ice
sheets is an illusion. They
focused their studies in West Antarctica where the ice sheet
is draped over a layer of marine sediments that is much more
slippery than rock. They suspected that this slippery sediment layer
and the above-average amount of subterranean heat the Earth
vents in West Antarctica, including numerous volcanoes, made
the West Antarctic Ice Sheet more prone to movement than scientists
had previously thought."When I first got into Antarctic studies,
ice sheets were thought to be very slow to respond," he recalls. "We had this preconception that any changes would be
on scales of centuries. Yet
there were rapid changes taking place. Ice streams would start and stop suddenly. And they are organized in a vast, interconnected network
of streams." Similar
to tributaries on land that flow into larger rivers, Bindschadler's
team discovered a vast network of coalescing tributaries feeding
into ice streams flowing toward the ocean.
Based on those discoveries and others over the past
few decades, glaciologists began to suspect that Antarctica's
ice sheets are not only sensitive to global warming, but that
there could be observable changes in our lifetime. What does that mean for sea level? Spread across a land area roughly equal to that
of the United States, the southern continent contains about
90 percent of all ice on our planet.".Bindschadler asserts,
Antarctica's ice sheets are entirely relevant. "The West Antarctic Ice Sheet has, does, and will continue
to affect sea level. We know that if this sheet changes in size,
it will change sea level. That connection is direct and irrefutable.".Today,
locked up in the West Antarctic Ice sheet-roughly the size
of Greenland-is enough water to raise global sea level by
another 5 meters (16 feet). Speaking of Greenland, its ice sheet has seen dramatic
melting in the last decade [see E. Rignot's research, JPL]. Greenland contains about 9 percent of all ice on Earth-also
enough water to raise sea level by 5 meters. Should either West Antarctica or Greenland surrender
its ice sheet to the ocean, much of the southern half of Florida
would be under water. Today, scientists see serious signs of stress
on both ice sheets [Greenland and West Antarctica]. Should they both collapse, sea level will be
10 meters (32 feet) higher, and cartographers will have to
redraw the contours of all Earth's continents." [ http://earthobservatory.nasa.gov/Study/TimeShelf/
. For a good satellite
image of Antarctica, click on this article.]
Positive Feedback Loops
What is Positive Feedback? Positive
feedback is when a side-effect of global warming contributes
to further global warming-thus accelerating the global warming
that is already in progress.
1)
One major side-effect of global warming are the retreat of
glaciers and ice sheets. This retreating becomes a positive feedback
to global warming. Why? Oceans absorb 90 percent of the solar energy
that hits them (esp. infrared spectrum) and reflect back only
10 percent of the suns radiant energy into outer-space. Ice sheets and glaciers and even snow-covered land
reflect back into outer-space 90 percent of the suns radiant
energy and absorb only 10 percent of it. So as ice sheets and glaciers retreat exposing more
ocean, a 90 percent increase in radiated solar energy is absorbed
by the earth and the ocean in particular, accelerating the
warming process. So
melting ice sheets and glaciers provide a huge positive feedback
to global warming.
2)
Another major positive feedback is "climatologists reported
in August 2005 that a one million square kilometer region
of permafrost peat bogs in western Siberia is starting to
melt for the first time since it was formed.at the end of
the ice-age." This will release methane, an extremely potent
greenhouse gas, possibly as much as 70,000 million tons over
the next 20 years. Similar
melting in eastern Siberia is occurring ( http://www.zmag.org/content/showarticle.cfm?SectionID=56&ItemID=8482
). The discovery of
permafrost peat bogs melting in 2005 implies that warming
is likely to happen faster than was predicted in 2001. As we stated earlier, methane is a powerful greenhouse
gas, and even when it is "burned up" in the atmosphere by
lightning combining it with oxygen (O2), or through UV photo-disassociation
in the upper atmosphere, it breaks down into water and CO2,
both themselves greenhouse gases. So the effects of released methane linger far beyond
its natural life cycle in the atmosphere.
3)
Carbon cycle feedbacks. Forest fires caused by drying of rain patterns
and rising global temperatures cause forest fires to occur
on a larger scale and more regularly. This releases stored carbon in the form of CO2 into
the atmosphere faster than the Carbon cycle can naturally
absorb, as well as reducing the overall forest area on the
planet, creating another positive feedback loop. Burning large sections of the Amazon has also
created another very large positive feedback loop in South
America.
4)
Warming in the UK has caused the ground to release 8 tons
more CO2 into the air than before, totaling now 12.7 tons
a year, virtually canceling out the 13 ton reduction in CO2
emissions the UK has been able to achieve in compliance with
the KYOTO accord. ( http://www.nature.com/nature/journal/v437/n7056/full/437205a.html
)
Water Scarcity
Water Scarcity & Decline in Agriculture: Decline in agriculture
(as the world's population reaches over the 6 billion mark). While there may be a very few isolated benefits
to global temperature rises, recent evidence shows global
yields will be negatively affected. "Rising atmospheric temperatures, longer droughts and
side-effects of both are likely to bring about a substantial
reduction in crop yields in the coming decades." ( http://www.royalsoc.ac.uk/event.asp?id=2844
) The region likely
to be worst affected is Africa both because its geography
makes it particularly vulnerable, and because 70 percent of
the population rely on rain-fed agriculture for their livelihoods. Tanzania is a good example of what has started to take
place. Tanzania's official
report on climate change suggests that the areas that usually
get two rainfalls in the year will get more, and those that
get only one rainy season will get far less.net result.33
percent less maize-the country's staple crop. ( http://www.guardian.co.uk/climatechange/story/0,12374,1517935,00.html
).
Water Scarcity: Coupled to
the affects of shrinking temperate zone glaciers, sea level
rises also threaten to contaminate groundwater, affecting
drinking water and agriculture in coastal zones. Most affected are the nations of Bangladesh and low
portions of Pakistan. Increased
evaporation, and due to higher temperatures, retention of
more water vapor in the atmosphere, will reduce the effectiveness
of reservoirs and rivers. Increased extreme weather will cause rain to fall in
such heavy amounts when it does rain, that the ground will
not be able to properly absorb it, leading to flash floods,
but less useful replenishment. The retreat of glaciers in the mountains of southern
Kazakhstan is creating environmental hazards that will affect
the lives of millions and the geopolitics of central Asia,
says Stephen Harrison." (
http://www.opendemocracy.net/globalization-climate_change_debate/kazakhstan_2551.jsp
) There has been a
25 percent decrease in annual rainfall in the Sahael over
the past 30 years (one percent per year). What this amounts to is that the Sahara desert's arid
conditions are extending five hundred miles further south
into densely populated central Africa. The Sahel's northern border, as you can see, is the
Sahara. So a semi-arid condition is moving south into
Africa's tropical "rainy" area. This is quite serious.
Earth's Tropical Belt Moving North and South: Over the past 26 years
the Earth's tropical belt of warmer air has widened by over
140 miles (2 degrees in latitude) moving towards the north
and south poles, according to Qiang Fu, and Thomas Reichler,
professor of Meteorology at University of Utah and Professor
John M. Wallace of University of Washington in Seattle, and
who were all part of a study team investigating this. This
warming of the atmosphere at these latitudes causes
the troposphere to bulge toward each pole, which gently pushes
the north and south jet streams farther north and south respectively. Such an event is believed to be causing the
expansion of the subtropical deserts into heavily populated
mid-latitudes (i.e. the Sahel area of Africa just south of
the Sahara region, southern Europe and the southern part of
the United States, lower parts of South America, just to name
a few areas.) "It's
a big deal. The tropics
may be expanding and getting larger," says study co-author
Thomas Reichler."If this is true, it also would mean that
subtropical deserts are expanding into heavily populated midlatitude
regions." This will,
if it continues, shift rain and snow precipitation toward
the poles. Currently, the troposphere over the period of
this 26 years has warmed 1.5 degrees Fahrenheit. [To read the full News Release from the University
of Utah, click on http://www.unews.utah.edu/p/?r=051906-1
]
NASA Study Suggests Extreme
Summer Warming in the Future
05.09.07
A new study by NASA scientists suggests that
greenhouse-gas warming may raise average
summer temperatures in the eastern United
States nearly 10 degrees Fahrenheit by the
2080s.
Image above: A
computer model projection of average daily
maximum temperatures over the eastern United
States for July 2085 (left) and July 1993 (right).
Areas in violet shading show temperatures of
26°C (79°F); green 30°C (86°F);
yellow 34°C (93°F); red 38°C (100°F);
dark purple 42°C (108°F). Credit: NASA/GISS
"There is the potential for extremely hot summertime
temperatures in the future, especially during
summers with less-than-average frequent rainfall," said
lead author Barry Lynn of NASA's Goddard Institute
for Space Studies and Columbia University,
New York.
The research found that eastern U.S. summer
daily high temperatures that currently average
in the low-to-mid-80s (degrees Fahrenheit)
will most likely soar into the low-to-mid-90s
during typical summers by the 2080s. In extreme
seasons – when precipitation falls infrequently – July
and August daily high temperatures could average
between 100 and 110 degrees Fahrenheit in cities
such as Chicago, Washington, and Atlanta.
To reach their conclusions, the researchers
analyzed nearly 30 years of observational temperature
and precipitation data and also used computer
model simulations that considered soil, atmospheric,
and oceanic conditions and projected changes
in greenhouse gases. The simulations were produced
using a widely-used weather prediction model
coupled to a global model developed by NASA's
Goddard Institute for Space Studies.
Image/animation
right: The animation to the right shows
a basic demonstration of the increase in annual
mean temperature in five year increments from
1880 through 2006. Warmest temperatures are
in red. Click image to view animation.+
Click for hi-res still image Credit: NASA/GISS
The global model, one of the models used in
the recently issued climate report by the Intergovernmental
Panel on Climate Change (IPCC), was utilized
in this study to identify future changes in
large-scale atmospheric circulation patterns
due to the build up of greenhouse gases. This
information was then fed into the weather prediction
model to forecast summer-to-summer temperature
variability in the eastern United States during
the 2080s. The weather model showed that extreme
summertime surface temperatures developed when
carbon dioxide emissions were assumed to continue
to increase about two percent a year, the "business
as usual" scenario. These findings are too
recent to be included in the latest IPCC report.
The weather prediction model used in this research
is advantageous because it assesses details
about future climate at a smaller geographic
scale than global models, providing reliable
simulations not only on the amounts of summer
precipitation, but also on its frequency and
timing. This is an important capability for
predicting summer temperatures because observed
daily temperatures are usually higher on rainless
days and when precipitation falls less frequently
than normal.
Observational climate data also showed that
sea surface temperatures in the Pacific Ocean
have a significant influence on summer air
temperatures in the eastern U.S.
"Relatively cool waters in the eastern Pacific
often result in stubborn summer high-pressure
systems over the eastern states that block
storms, reducing the frequency of precipitation
below normal,” noted study co-author
Richard Healy of the Woods Hole Oceanographic
Institution, Woods Hole, Mass. "Less frequent
storms result in higher surface and atmospheric
temperatures that then feedback on the atmospheric
circulation to further reduce storm frequency
and raise surface temperatures even more."
The global model simulated rainfall too frequently,
so that its surface temperatures were not appropriately
sensitive to interannual changes in Pacific
sea surface temperatures. "Since the weather
prediction model simulated the frequency and
timing of summer precipitation more reliably
than the global model, its daily high temperature
predictions for the future are also believed
to be more accurate,” added co-author
Leonard Druyan, NASA Goddard Institute for
Space Studies and Columbia University.
In comparison, the researchers say that a number
of the global models used in previous studies
of future climate change predict too frequent
precipitation that often falls too early in
the day. As a result, they tend to underestimate
the amount of future warming by reflecting
solar radiation back to space before it can
warm the surface and by simulating excessive
evaporation from the wet ground.
To the authors' knowledge, this is the first
study that has documented the impact of precipitation
simulation imperfections on model predictions
of surface air temperature. "Using high-resolution
weather prediction models, we were able to
show how greenhouse gases enhance feedbacks
between precipitation, radiation, and atmospheric
circulations that will likely lead to extreme
temperatures in our not so distant future," said
Lynn.
The study is published in the April 2007 issue
of the American Meteorological Society's Journal
of Climate.
“This expansion of the tropical zone could come upon
the US and southern to mid-Europe, mid-Africa, India etc
a lot sooner than this NASA article predicts due to the various
positive feedbacks that are presently occurring, such as
the disappearance of Artic sea ice and melting of frozen
tundra vegetation and subsequent massive methane releases
into the atmosphere. Nobody can predict accurately
how strong the positive feedbacks will be. Europe and
the southern portions of the US have already experienced
some of this projected rise already. A visitor to
Holland remarked that air-conditioners, once used as a luxury
in summer are now a necessity. The Dutch are also planning
ahead for sea-level rises, and are very worried. Does
the Bible predict this side-effect of Global Warming? God
talking to the Israelite nations, the nation of Israel, as
well as the nations descended from the 10 northern tribes
of Israel, wherever they ended up in the world says this
in Leviticus26:19-20, “And I will break
the pride of your power; and I will make your heaven as
iron, and your earth as brass: and your strength shall
be spent in vain: for your land shall not yield her increase,
neither shall the trees of the land yield their fruits.” Most
of prophecy, news in advance, is God just predicting what
we would do to ourselves, through sin, greed, avarice.”
What A Highly Qualified Christian
Science Writer Thinks About Global Warming
“So how
do we show we’re thoughtful on an issue like, say,
global warming?Now, first, I’m no expert on global
warming. [He’s
more of an expert than he admits to in collating the information
available, but he’s extremely cautious about drawing
dogmatic conclusions, the way I have become]I still consider myself in an information-gathering
phase, but I am seeing a few facts that I think are significant,
that we ought to be thinking about, especially if we plan
to tell anybody what we think. The
main thing we don’t want to be guilty of is what’s
called confirmation
bias. This
is an extremely important principle in science, and being
on the lookout for this is one of those things that make
science work so well, one of those things that, like Scripture,
warns us that human nature is deeply flawed.
Confirmation bias
Confirmation
bias is a kind of selective thinking; it means that, by nature,
we all tend to look for those pieces of evidence that confirm
what we already believe, and we tend to reject or rationalize
away those pieces of evidence that don’t line up with
our beliefs. Francis
Bacon had a lot to say about this problem of human nature,
as he was developing some of the modern rules of science. So
let me just give you a few pieces of evidence that have come
to me about global warming and let you do with them what
you will, but give them some thought.
The evidence
Here’s one piece of information that’s come up in the science
journals lately after some studies have been done:
and it’s based on the fact that global warming skeptics
have been claiming that experts in the 1970s were all saying
that the Earth was cooling, not warming. And
global warming skeptics keep showing this is true by quoting
from articles and news stories from the media back then.Well, it turns out that this claim is
mostly myth. A
survey of major journal papers published between 1965 and
1979 found that while 7 articles did see a cooling trend
for global average temperatures, over the same period,
44 journal papers showed that average temperatures were
expected to rise.It turns out that today’s global
warming skeptics usually cite media reports rather than
journal articles.But a study of the media stories shows
that even among the journalists, there was no consensus.The most cited journal paper that predicted
possible global cooling is a 1971 article in the journal Science, but soon after it was written, the author, climatologist
Stephen Schneider points out that better estimates on the
effects of aerosols came out, and better measurements of
other greenhouse gases and their warming effects came out,
changing his mind, so that now he says “it’s
absolute nonsense” to draw misleading comparisons
between early understanding of effects of these gases in
the 1970s compared to the level of knowledge today. [Sid
Perkins, “Cooling climate ‘consensus’ of
1970s never was,”Science, )ct. 29, 08.]A
second piece of relevant information to be aware of,
to throw a little monkey wrench into the works, is that
today, at least some researchers, in particular, Kyle Swanson
and Anastasios Tsonis, at the University of Wisconsin-Milwaukee
in the February Geophysical Research Letters, see evidence
for a temporary superposition of global cooling right now
over the longer trend of global warming caused by greenhouse
gases. [This
seems to be coinciding was a strong Solar Minimum we’ve
been in for about three years, 2007 to 2009, and it’s
still going.See http://science.nasa.gov/headlines/y2009/01apr_deepsolarminimum.htm .] In
fact, they report that mean global temperatures have been
mostly flat since 2001 and that they project that they
may drop over the next few decades, because the combined
natural forces of sunspots and volcanoes that have already
triggered the short-term cooling trend.The libertarian Cato Institute is using
their work as part of a large ad campaign to question global
warming.But to be clear, even these two researchers
say they believe that the tremendous increase in human-produced
carbon emissions is sure to have the greater long-range
effect on global temperatures.A
third factor to be aware of is that it’s true
that, as geologists know, there have been times in the
past when CO2 concentrations have ben much higher than
they are today. You
could use these facts to say that lots of carbon in the
atmosphere doesn’t make a lot of difference. Life
went on.The problem with saying that is at the
time when CO2 concentrations were so high in the deep past
[dinosaur times], the temperature was about 6 degrees [Centigrade]
higher, too, and the pole ice had melted, resulting in
seas that were 6 to 7 feet higher [I think he means meters,
not feet]. If
that were to happen today, with human populations being
where they are, a sea rise of that magnitude would about
wipe out places like Bangladesh, the ports of New York,
the Gulf coast, Galveston, Sacramento, the Netherlands,
and much of Indonesia. That’s
something to think about.
The consensus
I’ve seen
global warming skeptics claim that, with this knowledge of
large CO2 concentrations in the past geologists don’t buy the global
warming idea. But
here’s another fact to think about: When a poll was
taken of all earth scientists for the January 19 issue of
journal Eos Transactions, 90 percent said they believe that
the earth has warmed significantly since 1800. 82
percent of earth scientists supported the idea that humans
have caused this increase. [btw,
in boarding school and high school, earth science and chemistry
were my favorite subjects.]Among climatologists surveyed, 97 percent
supported the idea that humans are causing global warming.[So Dennis, you weatherman is in a distinct
minority.] Now
there was one group whose support took a nose dive compared
to everyone else, but it’s interesting that this was
not a group that necessarily had better knowledge of the
relevant climate facts but was a group that happened to make
a living from the fossil fuels that are being accused of
causing global warming: only 47 percent of petroleum geologists
supported the idea that humans are causing global warming
[that’s pretty good, almost 50% of petroleum based
geologists haven’t been warped by dollars and support
the facts.] So
their vested interest may or may not be significant, but
it’s an interesting consideration in the context of
our talking about confirmation bias.
I’m
not going to give you any grand conclusions about global
warming today.This is only meant to encourage you to
keep gathering information, and be thoughtful about it, especially
if you talk about the subject with unbelievers. But
since I mentioned Stephen Schneider, here’s a remark
he made that I think can be useful, from the May/June 2009
issue of Skeptical
Inquirer. I
think this is useful when we want to help unbelievers think
about what it means to bed skeptical, particularly when they
may find it convenient to avoid making a decision about Jesus
because of their skepticism. Schneider
says: “All good scientists are skeptical:I changed my mind from cooling to warming
in 1974 when the preponderance of evidence shifted… But
real skeptics still accept a preponderance of carefully examined
evidenced even when some elements of a complex systems
problem remain unresolved, and they do not pretendthat when there
are loose ends some well-established preponderances don’t
exist---that is beyond skepticisms to denial, or often political
convenience. [And
I might remind you, the earth’s cooling system is a very complex biochemical system, as
you will see as you read through this section titled Global
Warming.]So a skeptic questions everything but
accepts what the preponderance of evidence is, and a denier
falsely claims that until all aspects
are resolved we know nothing and should do nothing.”
If
you followed that, you know why I love that quote.It uses the global warming issue to show
that when a self-proclaimed skeptic sees there’s a
preponderance of evidence for a claim, but there continue
to be some loose ends, some unresolved complexities, if that
claim requires some action, a real skeptic will take action
rather than do nothing until every last loose
end is tied up. And
so the same reasoning can be used with all the evidence we
looked at in the first two-thirds of this information report
for God breaking into our history. The
thing that keeps a person from waiting for all the unresolved
complexities to be resolved when there is a preponderance
of evidence---isn’t healthy skepticism---it’s
denial.”“Fred Heeren, Info Report to Friends
of Day Star Ministries, May 2009.”
From
what Fred Heeren just said here, and what I have been able
to gather together as evidence in this section, the preponderance
of evidence show that global warming has been occurring from
the early 1970s to around the year 2004, where a slight dip
or leveling off in warming has occurred due to a deep solar
minimum we’re in. But
due to the severity of the warming histerysis curve earth
is in, the next solar maximum we enter will drive us back
into warming again, with all the projected dangers this article
brings out. If
you believe in God, it looks like he has thrown in a slight
delay to the prophecy mentioned about earth of iron and skies
of brass. And
yes, if you believe in God, you also believe he created not
just the earth but this vast universe of stars, which the
sun is one of that vast number. Now
how hard would you think it would be for God to bring on
a slightly larger solar minimum to slow down a warming of
earth’s climate, all to fit into his timing of prophecied
events? Although
man through his greed in using earth’s resources is
causing warming of our climate, God is going to make sure
the shit hits the fan just when he prophecies it will, which
may be sooner than you think. The
next solar max is due to occur in the latter part of 2009,
and then the warming trend will continue on it’s way.
Editor UNITYINCHRIST.COM
I
put this article together about Global Warming in 2005, and just got a
confirming update from two independent sources, dated in the Fall of 2016, and
these two updates are scary, to say the least.
Breakup of Larsen-A & B, Now What About The Largest Ice-Shelf, Larsen-C?
From
NPR International we get this:“Antarctica’s Ice Sheets Are
Melting Faster—And From Beneath” by Christopher Joyce, “October
25, 2016, 11:01 AM ET.Antarctica is
bigger than the U.S. and Mexico combined, and it’s covered in deep ice—more
than a mile deep in some places.Most of
the ice sits on bedrock, but it slowly flows off the continent’s edges.Along the western edge, giant glaciers creep
down toward the sea.Where they meet the
ocean, they form ice shelves.The
shelves are the specialty of Ala Khazendar, a geophysicist and polar expert at
NASA’s Jet Propulsion Laboratory in Pasadena, Calif.“You
have this floating plate of ice being fed by the glaciers flowing from the
interior of the continent,” he says, “while
having ocean water underneath it.”…Although the shelves float, they’re
still connected to the mainland…A team from JPL has been studying that
grounding line in several places [where the glacier, ice flow, is no longer
supported by bedrock, but is over open ocean] along the edge of the West Antarctica ice sheet.They used radar to look beneath the ice…They’ve found that the ice is
melting faster than they’ve ever seen.The researchers believe the cause is warm water circulating beneath the
ice shelf.Khazendar says the more the
bottom of the shelves melt, the more ice is exposed to warm water.“It
becomes a runaway process,” he explains, “which makes it unstable.” …There’s been a spate of research lately
showing that Antarctic ice is melting faster than previously thought—and
raising global sea levels.Khazendar
says the melting process appears to be irreversible.”[for the complete
article, see http://www.npr.org/sections/thetwo-way/2016/10/25/499206005/antarcticas-ice-sheets-are-melting-faster-and-from-beneath]
What
else could possibly cause the acceleration of glacier-flow to the seas, as well
as the breakup of Larsen A & B Ice Shelves, with
Larsen C now in real jeopardy?This next
set of quotes from a recent National Geographic online article will fascinate
you.
“Mysterious Winds Cause Rapid Melting of Antarctic
IceScientists suspect fohn winds may be responsible
for calving ice shelves… by Douglas Fox, “After studying Antarctica’s
warming climate for decades, scientists are making a surprising discovery:In some places, much of that abnormal warmth
is invading in the form of powerful, downhill winds called fohn (pronounced
“fone”) winds.Pettit, a glaciologist
from the University of Alaska in Fairbanks and a National Geographic explorer,
now suspects that these winds contributed to a series of dramatic glacial
collapses that have been steadily redrawing the map on the eastern side of the
Antarctic Peninsula for the last 30 years…”They
seem to impart a lot more melt onto the ice shelf than we had imagined,” says
Adrian Luckman, a glaciologist at Swansea University in the United Kingdom, who
studies this region of Antarctica.The
winds result from subtle changes in the atmospheric circulation due to climate
warming; they could have major consequences…”
LAND OF
MELTING ICE
“Antarctica
sits isolated at the bottom of the world, surrounded by a vortex of circumpolar
winds and ocean currents that swirl endlessly around it.“The
Antarctic Peninsula is the only barrier” to these winds, says Pettit, “the only thing they have to slam into.”The peninsula stretches 700 miles upward into
the Southern Ocean.Its mountainous spine
rises 5,000 to 9,000 feet above sea level, capped with a plateau of ice—forming
a wall that usually diverts the circumpolar winds northward around it.The east side of the Peninsula, shielded from
these winds, is especially cold.For
thousands of years, it was flanked by a series of vast ice plains—so-called
“ice shelves,” 800 feet or more thick, which float on the ocean, extending up
to 150 miles out over it.The ice
shelves had formed as dozens of glaciers oozed off the coastline of the
peninsula, merging their ice into a vast apron that spread over the sea.But all of this began to change in 1988.One by one, the ice shelves on the east side
of the peninsula began to collapse.The
first two ice shelves simply went missing—present at the beginning of a summer, then
gone by the end.But the collapse of Larsen A ice shelf in
1995 and Larsen B in 2002 were more violent events, documented by human
witnesses and satellite photos.Larsen B, covering an area larger than the state of Rhode Island, shattered
over a matter of days into thousands of shards, each larger than an aircraft
carrier.Larsen A and B showed similar
symptoms leading up to their disintegration.Both ice shelves lost their insulating cover of snow, laying bare a
darker, icy surface that absorbed more heat from the sun.Melt ponds grew and metastasized across their
surfaces.Then this water drained into
deep cracks in the ice.Its weight
pushed the cracks ever deeper, like a wedge, until it broke through the bottom,
says Theodore Scambos, a glaciologist at the National Snow and Ice Data Center [in Boulder, Colorado], who has
studied these ice shelves for many years and camped with Pettit in Antarctica
last February.These insights seemed to
explain the sudden collapse of four ice shelves in 15 years…Scambos, Pettit,
and a handful of other scientists now suspect fohn winds helped set the stage
for recent ice shelf collapses.These
events continue to have far-reaching consequences.
ACCELERATING
SEA LEVEL RISE
“The
collapse of the Larsen A and B ice shelves in 1995 and 2002 removed a buttress
that slowed and stabilized glaciers flowing off the peninsula’s coastline.With that backdrop removed, the glaciers have
accelerated to as much as nine times their original speed—vastly increasing the
rate at which they dump ice into the ocean and fuel sea level rise.Continued
climate warming is expected to increase frequency and strength of fohn winds on
the peninsula, says Pettit.The weather
stations installed by her and Scambos have already recorded temperature spikes
as warm as 60 degrees F…Scambos is already seeing their impact, as does the
surface of the sea ice that sits in front of the ice shelf.“The
areas of high wind speeds and warm winds are evaporating the snow, probably
melting it a bit too,” he says—exposing older, bluer ice on the
surface.That darker ice will absorb
more heat during the Antarctic summer from November to February, creating large
melt ponds that cold trigger the final collapse of Scar Ice Shelf…
HOPE FOR A
GIANT ICE SHELF?
“Just
a few miles south sits the next ice shelf inline, aptly named Larsen C.It dwarfs the others, covering an area as
large as Maryland, and stabilizing more glaciers than all four previously
collapsed ice shelves combined.On June
10 [2016], a team of British scientists led by Luckman reported a disturbing
discovery on its north end.Larsen
C should be covered by 200 feet of insulating snow.But they found that in some places, all but
10 feet of it had already vanished—erased, in part, by fohn winds.That finding raises the specter
that melt ponding will continue to increase until it threatens the
stability of Larsen C.”[emphasis mine.For the complete article, see: http://news.nationalgeographic.com/2016/11/foehn-winds-melt-ice-shelves-antarctic-peninsula-larsen-c/]
So
in the fourteen years since I put this article together, with all the current
data I could collect, the warming and melting processes haveaccelerated their rate of increase,
along with the times-9 increase in glacial flow-rates in Western Antarctica.
“The Pine Island
Ice Shelf is a slow-motion train wreck…Its edges are shredded by rifts a
quarter mile across.In 2015 and 2016 a
225-square-mile chunk of it broke off the end and drifted away on the Amundsen
Sea.The water there has warmed by more
than a degree Fahrenheit over the past few decades, and the rate at which ice
is melting and calving has quadrupled.
“the Pine Island Glacier [is] one of several large glaciers
that empty into the Amundsen Sea.Together they drain a much larger dome of ice called the West Antarctic
Ice Sheet, which is up to two and a half miles thick and covers an area twice
the size of Texas…That makes it especially vulnerable to the warming
ocean.If all the vulnerable ice were to
become unmoored, break into pieces, and float away, as researchers increasingly
believe it might, it would raise sea level by roughly 10 feet, drowning coasts around the
world…The ice sheet is held back only by its fringing ice shelves—and
those floating dams…are starting to fail.” [National Geographic, July 2017, p.
32, sel. portions]
“But
even more worrisome is the neighboring Thwaites Glacier, which could
destabilize most of the West Antarctica Ice Sheet if it collapsed.“These are the fastest retreating glaciers on
the face of the Earth,” says Eric Rignot, a
glaciologist at the NASA Jet Propulsion Laboratory in Pasadena,
California.Rignot has studied the region for more than two decades, using radar from aircraft and
satellites, and he believes the collapse of the West Antarctic Ice Sheet is
only a matter of time.The question is
whether it will take 500 years or fewer than a hundred—and whether humanity
will have time to prepare.“We have to
get these numbers right,” says Rignot.“But we have to be careful not to waste too
much time doing that.”” [ibid. p. 41, sel. portions]
The
melt rates were ‘just crazy,’ researcher Adrian Jenkins says. ‘It was beyond
our concept that a glacier would melt that fast.’
“It
took scientists a long time to realize just how quickly West Antarctica’s ice
could melt…warm water was coming from the South Pacific, more than 200 miles
north.It was so heavy with salt that it
was following the floor of a submarine canyon, which sloped down toward the glacier…Now
that same canyon was channeling warm ocean water under the Pine Island Ice
Shelf.Somewhere tens of miles inland,
the warm water was finding the “grounding line”:the place where the glacier lifts off the
seafloor and becomes a floating ice shelf.Hitting that wall of ice, the warm water was eroding it, producing a
steady stream of melt-laden seawater.Because it was cooler and fresher, it was less dense, and so it was
rising above the warmer, incoming water and flowing back out to sea just under
the shelf.
By measuring the amount of this
freshwater, the researchers could estimate how much ice was being lost.The melt rates “were just crazy,” says
Adrian Jenkins, a glaciologist from the British Antarctic Survey in
Cambridge...the ice shelf was losing 13 cubic miles of ice per year from the
underside; back near the grounding line, the ice was
probably thinning up to 300 feet per year.“It was just beyond our concept that a glacier would melt that fast,” Jenkins
says.Over the next 13 years he and
Jacobs tried three times to return to Pine Island…When they finally got back
there on the Palmer in January 2009,
they found that the melt rate had increased by about 50 percent.This time they came equipped with a new
tool:a yellow robotic submarine called Autosub3…On its first three dives,Autosub3 discovered that the ice shelf had thinned enough to lift off a submarine ridge
that, running across its width, had once supported and stabilized the ice
shelf.That had opened a gap that was
allowing warm water to flow in and melt the underside of the ice even
faster…LARGE SWATHS OF WEST ANTARCTICA are hemorrhaging ice these days…Average
annual temperatures on its west side have risen nearly 5 degrees Fahrenheit
since 1950—several times faster than the rest of the planet—and the winters have
warmed an astonishing 9 degrees.”[ibid.
pp. 42-43, sel. portions]
Research
indicates that the collapse of major glaciers that flow into the Amundsen Sea
is now unstoppable
“Ian
Howat, of the Byrd Polar and Climate Research Center in Columbus, Ohio, is
another glaciologist who’s watching Pine Island closely…It’s unclear when the
entire ice shelf might disintegrate.The
“warm” water flowing underneath it from offshore is only 4 to 6 degrees
Fahrenheit above freezing.But roughly
3,000 cubic miles of it arrives everyyear, which means the ice shelf is
receiving an amount of heat that exceeds the output of a hundred nuclear power
plants, operating 24/7…In fact, research by Rignot and others over the past few years indicates that the collapse of several major
glaciers flowing into the Amundsen Sea is now unstoppable…Each
increment of retreat exposes a greater ice surface to warm ocean water.It’s a runaway process—and scientists are
urgently trying to figure out how fast it will run.
The ice shelves, Fricker says, “are the canary in the coal mine.”Because they’re already floating, they don’t raise sea level themselves
when they melt—but they signal that a rise is imminent, as the glaciers behind
them accelerate…The retreat and hemorrhage of these glaciers “will accelerate
over time,” agrees Rignot….To consider the worst
case, then, scientists must turn their eyes toward East Antarctica, home to
more than three-fourths of all the ice on Earth.”[ibid. pp. 46-47, sel. portions]
If
Totten Glacier were to collapse, sea level could rise 13 feet—threatening many
of the world’s largest cities.
“Until
recently the East Antarctic Ice Sheet was considered secure; unlike West
Antarctica, it sits on high ground.But
mapping with ice-penetrating radar has revealed a low-lying region cut by
glacially carved channels that drop as far as 8,500 feet below sea
level—perfect for guiding warm ocean water deep into the heart of the ice
sheet.The Totten Glacier is the largest
coastal outlet in the region.If it
collapsed, global sea level could rise 13 feet—“roughly as much as all of West
Antarctica,” Rignot points out, “One glacier alone.”In January 2015, the Australian icebreaker Aurora Australis became the first ship
to reach the front of Totten…it found deep, warm water flowing under the ice
shelf, at a rate of 4.5 cubic miles a day.” [ibid. p. 48, sel. portions]
content
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