West Antarctic may have ice-free future, but global change not to blame
2.07 p.m. ET (1814 GMT)
October 7, 1999
| By Randolph E. Schmid, Associated Press |
As scientists have been increasingly able to document melting and the
discovery of icebergs breaking off from Antarctica in recent years, concerns
have risen that human-induced climate change could be damaging the Antarctic ice
sheet.
But the future of the West Antarctic ice sheet "may have been
predetermined when the grounding line retreat was triggered in early Holocene
time,'' about 10,000 years ago, a team of scientists led by Howard Conway of the
University of Washington reports in Friday's edition of the journal Science.
The grounding line is the boundary between floating ice and ice thick enough
to reach the sea floor, and the scientists found that line has receded about 800
miles since the last ice age, withdrawing at an average of about 400 feet per
year for the last 7,600 years.
"It seems like the rate (of melting) that been going since the early
Holocene is similar to the rate right now,'' Conway said in a telephone
interview. "Collapse appears to be part of an ongoing natural cycle,
probably caused by rising sea level initiated by the melting of the Northern
Hemisphere ice sheets at the end of the last ice age.''
Continued shrinking of the ice sheet, perhaps even complete disintegration,
"could well be inevitable,'' the report concluded.
The ice sheet's disappearance is of concern because of estimates that its
complete melting could raise the global sea level by 15 to 20 feet, swamping
low-lying coastal communities around the world.
At the current rate of melting, that will take about 7,000 years, the
researchers estimate. Conway said the melting annually contributes about 1
millimeter — nearly one-twenty-fifth of an inch — to sea-level rise.
While the study indicates global warming is not causing the melting, climate
change remains a problem, Conway said: "Global warming could well speed the
process. Our study doesn't address that problem.''
Environmentalists have grown concerned that industrial chemicals added to the
atmosphere are trapping heat like a greenhouse, causing the Earth's temperature
to increase. There is disagreement, however, about the process and how great a
hazard it may pose.
Conway's report is one of three in this issue of Science focusing on the
Antarctic ice sheet. In the others:
—Scientists studying satellite-based measurements found a complex system of
tributaries feeding major rivers of ice on the West Antarctic Ice Sheet. This
web of tributaries forms a transition zone between the sluggish inland ice and
the swiftly moving ice streams closer to the margins.
—Other researchers, using the ages of volcanic debris that erupted onto the
ice sheet, reconstructed the past elevation of the West Antarctic Ice Sheet as
it began to melt just after the end of the last ice age. They concluded the
sheet was not the source of a massive flow of meltwater into the oceans 10,000
years ago.
West Antarctica is the section of the continent south of the tip of South
America. It is covered by an ice sheet that extends about 360,000 square miles
— close to the combined areas of Texas and Colorado.
Conway's team calculated the movement of the grounding line using evidence
gathered from raised beaches and radar imaging of subsurface ice structures. The
timing of start of the melting was determined by carbon-14 dating of samples
found on raised beaches.
The report said:
While the study indicates global warming is not causing the melting, climate
change remains a problem, Conway said: "Global warming could well speed the
process. Our study doesn't address that problem.''
No matter what scientific evidence refutes the "political wisdom",
it will still be the political will that controls the use of resources that
address these scientific issues; you don't expect anyone to give up the power
they have accrued, now do you?
It is instructive to understand how these ice-sheets formed; as the air and
the seas cooled, the free water began to freeze, while the saline-rich deep
ocean waters receded and remained unfrozen. This process is similar to the
operation of an ordinary ice-cream "freezer"; the reason that ice,
when laced with table salt (or rock salt) causes the ice-cream mixture to harden
is based on the fact that freezing water gives up its contaminants upon
freezing, and by forcing sodium chloride back to the ice, the solution returns
to a liquid while its temperature remains close to its frozen state.
By conduction, the heat of the ice-cream mixture is drawn away, thereby
"freezing" the ice-cream.
On the Antarctic shelf, the lower levels of water are more saline than those
at the surface, so that they remain unfrozen. However, at some point, a reduced
temperature will freeze the brine and separate the salt to fall to the bottom,
or floor, of the ocean.
Climate changes occur through surface heating and require a lot of time to
melt down through the ice.
Ocean floor disturbances, such as erupting magma could alter this process
dramatically, yet there seems to be no evidence of this occurring.
For my information on Global Climate Change (or Global-Warming),I rely on http://sepp.org
Dr S. Fred Singer is a very well-recognized environmental expert with no axe
to burn. New Heat on Global Warming "Despite
Encironment Canada's dire warnings, atmospheric physicist S. Fred Singer says
global warming is still suspect -- and a new study shows a hotter climate could
be beneficial." Environment Canada has
the daunting task of persuading Canadian citizens that a warmer climate would
hurt them so much that they should pay a lot more for gasoline to discourage its
use. It's a tough sell: peddling this story to a population that is largely
skeptical that the world faces a climate crisis of catastrophic proportions.
It's especially difficult when many academic studies pour cold water on the
overheated claims of global warming theorists and political activists. The prestigious Cambridge
University Press has just published the findings of a group of 26 economists,
headed by a Yale University resource expert, who studied what would happen to
human activities ranging from agriculture to recreation to water use if the
earth substantially warmed in the next century. Contrary to media spin, the
economic consequences would be on the whole positive, not negative. Agriculture
and forests would particularly benefit because of the fertilizing effect of
rising atmospheric carbon dioxide (CO2), a greenhouse gas but also plants' basic
food source. GDP would increase substantially in a warmer world, as would
personal income and standards of living. Environment Canada does
not report these results in "The Science of Climate Change" -- its
latest propaganda offering to the media and the public, recently posted on the
department's Web site. Environment Canada describes this posting as short,
science-based answers to questions on different aspects of climate change that
"can be used for briefing documents, as media lines and within publications
and presentations" by government officials. As you might expect, it is a
gloomy document that uses facts selectively and puts a negative spin on future
events. Worst of all, it is not scientifically accurate. To discount critics,
the brochure claims that "the vast majority of scientists studying climate
change agree," but leaves unsaid the distinct possibility that these
scientists are government-funded and that governments have a point of view that
has little to do with science. Governments are unlikely to fund researchers who
are not already concerned about global warming. Most scientific skeptics do not
depend on government funding. They either have tenure at universities or income
from pensions or other independent sources. Environment Canada also
dismisses climate change critics as a "small number of dissenting
scientists primarily located in the United States." Certainly, the
17,000-plus (most with advanced academic degrees), who last year signed the
Oregon petition against the 1997 Kyoto Protocol, cannot be dismissed as a
"small number of dissenting scientists." Scientific dissent does exist
and on at least two levels. First, whether human actions are causing a
significant warming. Second, whether there is any warming trend at all. The climate is always
changing, just like the weather. Last year may have been the hottest year on
record, but one year doesn't make a trend. People sometimes ask me if it's
getting hotter or colder. The only correct answer is "yes." It all
depends on the choice of time period. The climate warms from January to July and
cools from July to December, and we understand why that is. But what about
climate variations from year to year, from decade to decade, century to century? To answer this question,
we have to look at historic climate records. Since the end of the last ice age,
about 11,000 years ago, glaciers covering Canada and the northern United States
have retreated, leaving behind the Great Lakes. But the climate has not been
steady since then. Even before written records and thermometers, information in
ocean and lake sediments, in Greenland and Antarctic ice cores and from the
width of tree rings indicate large temperature changes. Scientists studying
these "proxy" data have established the following picture: About 6,000
years ago, the earth was much warmer than today, and about 1,000 years ago,
there was another warm period during which Vikings settled and grew crops in
Greenland and may even have explored the coast of Labrador. This benign period
was followed by the severe "Little Ice Age," which lasted off and on
until about 1850. Then, both proxy and scientific instruments indicate a
significant increase in temperature, particularly between 1900 and 1940. The
data show that the recovery was a global event, likely due to natural causes. Since World War II,
growing populations and increasing industrial activity put billions of tons of
CO2 into the atmosphere, mainly from the burning of fossil fuels. CO2 is a
greenhouse gas, yet the climate cooled significantly between 1940 and 1975. The
earth had another sudden warming between 1975 and 1980, but from then on, the
story becomes complicated. Surface thermometers show a continued small warming
up to the present, while satellites, as well as balloon-borne radiosondes, do
not. A good hypothesis is that local warming in urban areas has contaminated
surface data, affecting many weather stations but not the globe as a whole. Recently, direct
temperature measurements (with thermometers) on an ice ore from Greenland have
confirmed this picture. Writing in the renowned Journal Science, researchers
state explicitly that the "temperature cools between 1940 and 1995."
This clearly contradicts the results of climate models, which all predict that
the warming at high latitudes should greatly exceed the global average. Returning to the question
of climate variations, we can now avoid much confusion. When Environment Canada
tells us that the climate warmed in the last 100 years, we can reply, "Yes,
but it did not warm in the last 50 years and may have even cooled in the last 20
years." When it tells us that this century is the warmest in the last 600
years, we can reply, "Yes, but not in the last 1,200 years." What about the human
influence on climate change? Urban heat has assuredly affected local
temperatures. But has a nearly 50% increase in the overall greenhouse-gas level
since about 1850 caused a global warming? It's certainly plausible and expected
from theory, but, so far, natural climate variability appears to dominate over
any human effect. Distinguishing between
natural and human-related causes is a very subtle problem. Many experts are
looking for "fingerprints" of human influence. And indeed, they've
found some faint ones: Northern winters have become a little warmer, as have
cold nights. But contrary to what many believe, hurricanes are diminishing, both
in strength and in frequency. And, best of all, a recent analysis shows that the
ongoing sea-level rise slows during warmer periods. The reason: Increased
evaporation transfers water from the oceans to the ice caps in the form of snow.
This would be an important fact to add to Environment Canada's fact sheet on the
"Science of Climate Change." Climate scientists are
still unsure why the increase in atmospheric CO2 has not produced the
substantial global warming predicted by theory. It may be that solar variability
accounts for most of the observed climate fluctuations. Or, perhaps, warming of
the oceans increases evaporation and cloudiness, which reduces the amount of
sunlight reaching the surface and counteracts the warming. Although Environment
Canada may disagree, the computer models and climate predictions it bases its
theories on remain unproven. It would be wise, therefore, to postpone drastic
policies until the scientific picture becomes much clearer. [S. Fred Singer, PhD,
is an atmospheric physicist, professor emeritus of environmental sciences at the
University of Virginia and the president of the Fairfax-based Science &
Environmental Policy Project, a non-profit policy institute.] LONDON, (Reuter) - The world's climate is being heated up by the sun, not by
the actions of mankind, according to a book published this month.
The book, "The Manic Sun", by scientific journalist Nigel Calder,
says the "greenhouse" theory which reckons that increases in world
temperatures result from excessive burning of fossil fuels is wrong, and has
been sustained by science corrupted by pressure from politicians.
Any climate warming has occurred because of the influence of the sun,
responsible for fluctuations in temperature and weather for centuries. Calder
says British scientists in general and Britain's Meteorological Office in
particular have misled the public.
The Meteorogical Office said it stuck by its methods, which date back more
than 100 years, and denied what its spokesman called another paranoid attack on
scientists' honesty.
Scientists working for the United Nations Intergovernmental Panel on Climate
Change (IPCC) also come under attack from Calder.
IPCC scientists have backed the theory that the climate was warming up
because of carbon dioxide (CO2) build-up from the burning of fossil fuels.
The IPCC's most recent report in 1996 said that the hand of man was now
discernible in climate change.
Developed nations promised at the 1992 Earth Summit in Rio de Janeiro to cut
carbon dioxide to 1990 levels by 2000. Carbon dioxide is said to trap the sun's
heat, raising the earth's temperature.
Environmentalists say the increased temperature will cause havoc with the
climate. Melting polar ice would raise sea levels and submerge low-lying areas
and wipe out some island nations.
Traditional agriculture would be decimated by intolerable temperatures.
Severe storm frequency would increase inexorably.
At a recent conference in Brussels the World Energy Council, a private
organisation which says it seeks balance in energy issues, said the Rio targets
would not be achieved. It said they should be delayed to permit more realistic
goals to be set.
"We can state with some confidence that the industrialised countries'
CO2 emissions are currently over five percent above 1990 levels, and in
aggregate are likely to be over eight percent up on 1990 levels in the year
2000," WEC deputy secretary-general Michael Jefferson told the conference.
Nevertheless the momentum behind the Rio Summit powers on. Next month in New
York, world leaders including U.S. President Bill Clinton will assess the
progress made in the five years since Rio.
In December, IPCC delegates will gather in the Japanese city of Kyoto when
some countries will seek mandatory CO2 emission targets.
Industrial groups and trade unions in the United States are beginning to
agitate against such action.
They say that if industrial nations agree to one-sided cutbacks in CO2
emissions, this will cut industrial output, and effectively transfer wealth and
jobs to emerging nations which do not have to meet such targets, at least in the
short term.
If the sun theory gained ground, the insistence by environmentalists that
fossil fuel burning must be cut back would be hard to maintain.
Calder said that recent discoveries by Danish scientists show that the
world's climate has fluctuated over the centuries because of the influence of
the sun.
"I firmly believe that the whole effect of the global warming till now
is due to the sun," he quotes Danish Meteorological Institute's Eigil Friis-Christensen
as saying.
Friis-Christensen says the climate is crucially influenced by cosmic and
solar rays impacting on the earth's magnetic field. Cosmic rays vary with the
solar cycle and interact with the solar wind which has a direct impact on the
world's cloud formation and therefore on the climate.
Friis-Christensen's research used ice cores drilled in Greenland to trace
back climate change for some 3,800 years.
Calder said that the credibility of IPCC predictions has already been
undermined by errors and omissions, causing it to cut back on some of its
theories.
Another blow to the Gloom and Doom environmentalists. Guess we don't need to
abandon New York City just yet UNFORTUNATELY!!!!!
by S. Fred Singer
Comment published in Financial Post (Toronto),
August 7, 1999.
Global climate is said to be warming because of sun, not man