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Unformatted text preview: Global Climate Change WASHINGTON (CNN:
March 19, 2002)
-- A new giant iceberg, “B-22”, is
adrift off Antarctica.
-- broke off from the mainland
into the Ross Sea.
-- is about 53 x 40 miles (= size
of Rhode Island.) Open Ocean
B-22 -- One 183 x 22 miles ( = 2x size
of Deleware) broke off near
there in March of 2000. SO WHAT?
WHO CARES? Ice Shelf An unusually high
number of icebergs
have calved from
Antarctica in recent
years all around
Antarctica. Some researchers
speculate there is a
to global warming. Grinnell Glacier in Glacier National Park, Montana; photograph
by Carl H. Key, USGS, in 1981.
The glacier has been retreating
rapidly since the early 1900's.
The arrows point to the former
extent of the glacier in 1850, 1937,
Mountain glaciers are excellent
monitors of climate change; the
worldwide shrinkage of mountain
glaciers is thought to be caused by
a combination of a temperature
increase from the Little Ice Age,
which ended in the latter half of
the 19th century, and increased
greenhouse-gas emissions. Could global warming be man-made through our emission
of ‘greenhouse’ gasses?
of HOW DOES GREENHOUSE GLOBAL WARMING WORK?
HOW --Short wave (ultraviolet) incoming radiation heats earth;
-- Long wave (infra red) outgoing radiation blocked by greenhouse
gasses. If sea level rises 1 m, who would care?
1. In Florida: (see lab
2. Island nations of the IndoPacific (e.g., Marshall Is.,
Maldives)? Will be
3. In China? 70 million
people would have to be
4. In Bangladesh? 32 million
evacuated (1/5 of country
would disappear). West Gulf Coast Delaware Bay Georgia Antarctic Ice Sheet
--99% covered in ice up to 2 miles thick East and West Antarctic Ice Sheets Antarctica with the ice removed The East Antarctic Ice
Sheet is grounded above
sea level. The West Antarctic Ice
Is grounded up to 2000 m
below sea level. Which do you think is the
more stable and why?
(see lab exercise) If the WAIS melts, sea level will rise 20 m. Who cares?
(see lab CDROM exercise) In Louisiana?
½ the state
flooded. If all of the ice caps of the world melt, sea levels will rise
72 m (236 ft).
). Who Cares?
What do the tabloids say?
Statue of Liberty What do scientists say?
-- Liberty would hardly get
her feet wet.
-- but, SF’s Golden Gate
Bridge will flood (is 220 ft
above sea level). What are the long term trends? A scene from the medieval “Little Ice Age” What does history say?
--Global temperatures are warmer today than anytime during
the past 1000 yrs. Tree ring and instrumented temperature measurements In Antarctica today, scientists say:
The Antarctic Peninsula, McMurdo area, and Southern
Ocean are warming:
--up 4-5o C since 1940’s.
--Fur and elephant seas
are invading from the
--ditto Gentoo and
displacing Adélies [pix].
--glaciers are retreating.
Adélie penguins (S. Wise, 2000) Conflicting science reports, austral summer, 2002:
--A heat wave at McMurdo and South Pole Station, highest in 2 decades
(Antarctic Sun, 1/25/02)
--“The Southern Ocean is warming 2x as fast as the global ocean”
(S. Gille, Nature, 2/14/02). Cooling trends:
--The “Dry Valleys” near McMurdo Sound have cooled 1 o F in past 35
yrs (NSF, 1/17/02).
--The thickness of the West Antarctic Iced Sheet has increased ( Nature,
1/17/02). “A virtual train wreck of information for climate researchers”.
Are these merely normal local weather effects? Scientists say: -- “Only long-term, worldwide studies can confirm
global warming, its causes and likely effects” -- “More research is needed” What are scientists in
the Department of
Geology doing? What are scientists in the
Antarctic Marine Geology
Research Facility doing?
--have initiated “SHALDRIL”
to study past ice sheet
behavior on the Antarctic
margins (beginning 2004) What is George Bush’s plan?
--Reduce greenhouse gasses through incentives to
business over the next 10 years.
--Institute a largely voluntary plan that contrasts sharply
with the tougher mandatory Kyoto (Japan) Protocol.
--Reject the Kyoto Protocol because some developing
countries are exempted from it. What does the opposition say?
Sen. Jim Jeffords, Independent (Vermont) on Valentines
-- "Is a love letter to the status quo and the polluting past.“
-- fails to acknowledge that the U.S. is responsible for
emitting 25 percent of the world's greenhouse gasses
(however, Europe accounts for most of the other 75%, so
they aren’t overly enthusiastic about Kyoto either).
The debate goes on…… Predicted Future Trends The future according to the Intergovernmental Panel on
climate Change (IPPC): (see lab exercise). ...
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This note was uploaded on 10/23/2011 for the course GLY 1000 taught by Professor Parker during the Spring '11 term at FSU.
- Spring '11