Download 30 Oct 2004

MODERN TIMES
by Art Hobson
[email protected]
Ice Sheets, Kyoto, And Global Warming
A lot has happened on the global warming front since my last report on 20
March (http://physics.uark.edu/hobson/ ).
The list of possible disasters has just become more dangerous. That list
includes shutting off the oceanic "pump" that keeps the Gulfstream and other
global ocean currents circulating; a sudden release of deposits of methane--a potent
global warming gas--from the ocean floor; melting of the entire Arctic ice cap
within a few decades; and breakup of the mile-thick West Antarctic Ice
Sheet. There are recent reports that this last disaster, the breakup of the WAIS,
may be already beginning.
Although it would take thousands of years for global warming to directly
melt the entire WAIS, there are subtle ways to destabilize it. This huge ice sheet
has always slid slowly downhill toward the sea, with a rough balance between the
amount of ice disappearing into the water each year and the amount added from
snowfall. Since 1990, parts of the WAIS have begun sliding much faster, carrying
two or three times as much ice into the sea as is replaced by snowfall. Glacier
specialists aren't sure why this is happening, but they believe that warmer ocean
waters are eating away at the underside of the large ice shelf where it is first
"grounded" on the land, and this loosens the ocean end of the WAIS, causing it to
slip toward the sea. As the ocean-end slides downhill, it appears to drag the entire
WAIS--three times the size of Texas--along with it.
The WAIS actually comprises six separate glaciers, and only one of the
smaller ones is increasing its seaward flow. But because they don't entirely
understand the process, experts can't say whether the WAIS's two largest ice
shelves--each of them the size of Texas--could also begin sliding downhill. The
entire WAIS could gradually slide into the sea during the next few centuries,
raising global sea levels by a disastrous 16 feet, or a few feet every century. This
sliding process, once it has gotten very far along, could be impossible to stop. A
rise of a few feet in the next 100 years would be disastrous. Sea levels have risen
by 4 to 10 inches during the past century, and coastal nations such as Bangladesh
are already feeling the pain.
On the positive side, and little-noted by our environmentally-negligent press,
Russian President Vladimir Putin has approved the Kyoto treaty on climate change
and it will soon be ratified by the Russian parliament. The treaty, drawn up in
1997 at an international meeting in Kyoto, Japan, sets limits for emissions of the
gases that cause global warming. However, the treaty will not actually be legally
binding until it has been ratified by nations representing 55 percent of the world's
industrial carbon emissions. Once it becomes legally binding, the treaty will
require the ratifying nations to obey the limits set by the treaty. Although 124
nations have ratified the treaty, the USA is not among them. Ever since 2001,
when President Bush reversed President Clinton's pro-Kyoto stance and rejected
the treaty, the USA has been the main holdout nation preventing the treaty from
entering into force. Because the USA alone emits over 25 percent of the world's
total, it's been hard achieve the 55 percent figure. Ratification by Russia, which
accounts for 17 percent of global emissions, will put the ratifying nations above 55
percent and bring the treaty into force.
A lot will change once the treaty is in force. Signatory industrialized nations
must then reduce their emissions by 5 percent below 1990 levels, by 2012. To
achieve this at the least possible cost, these nations will establish a "carbon trading
system" under which they will receive "carbon emission permits" allowing each
nation to emit a prescribed amount of carbon each year. The permits will be
tradeable: Nations having more permits than they need can sell them to other
nations, putting an economic premium on reducing carbon emissions. The USA
will be left out of the commerce engendered by this trading system. We will fall
increasingly behind the world in constraining carbon emissions, and carbonemitting US goods will be shunned by the rest of the world.
This is happening as the scientific establishment expresses concern about the
Bush administration subjecting scientific issues such as global warming to political
tests. After a four-year history of rejecting the science of climate change, our
president has grudgingly accepted the reality of global warming. However he has
refused to recommend any remedy stronger than voluntary business measures, and
research toward a distant hydrogen economy. If the president is seriously
interested in action on global warming and energy issues, solutions are close at
hand. A 50-cent gasoline tax, with the proceeds perhaps distributed back as
income tax relief, would reduce foreign oil imports, would ultimately save money
for consumers, and would reduce carbon emissions. Raising gasoline efficiency
standards to a realistic and achievable 40 mpg would accomplish much more than
Bush's tenuous hydrogen initiative.
It's depressing that the press and the presidential candidates have been so
negligent about environmental matters in general and global warming in
particular. Let's hope that we don't need a real disaster, such as the WAIS sliding
into the sea, to wake us up. Besides being our wake-up call, it could be
civilization's death knell.