AIT after movie

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Transcript AIT after movie

A Closer Look at
“An Inconvenient Truth”
Post-AIT Evaluation
Sheridan High School
British Ruling on Showing AIT to
British School Children
• In 2007 a British judge ruled that the movie can be
shown in classrooms, but only if accompanied by
teacher guidance notes balancing Gore's "one-sided
• After listening to government witnesses,
environmental campaigners, and skeptics on global
warming argue their case, the judge described
Gore's film as "broadly accurate" in its presentation
of climate change.
• At the same time he also listed nine significant
errors in the movie which, he said, reflected a
general context of "alarmism and exaggeration"
surrounding climate change.
Images May Be Misleading
• AIT introduces
CO2 with a
picture like this.
• The black stuff
is steam, not
Source: Idso et al. (2003)
Experimental data
indicate that the
100-ppm increase
in CO2 levels
since preindustrial times
has increased
average yields by
60% for wheat,
33% for fruits and
melons, and 51%
for vegetables.
Images May Be Misleading
The most recent picture of Kilimanjaro in AIT is not taken
from the same side of the mountain
Scientific Evidence Does Not
Prove This Point
Mt. Kilamanjaro, Africa
•AIT “blames” CO2-induced
warming for the disappearing
Snows of Kilimanjaro
•But snows have been
disappearing since 1880 due to a
sudden shift from moist to dry
Source: Molg et al. (2003)
Scientific Evidence Does Not
Prove This Point
Gore argued that coral reefs all over the
world were bleaching because of global
warming and other factors.
The judge cited the IPCC view that it was
difficult to separate the impact of
stresses on coral reefs caused by
climate change "from other stresses such
as over-fishing and pollution."
Scientific Evidence Does Not
Prove This Point
• Lake Chad is drying up.
• It is more likely due to
– population increase,
– over-grazing, and
– regional climate variability
Than global warming.
Scientific Evidence Does Not
Prove This Point
Hurricane Katrina devastation
There is insufficient evidence to show
that global warming was the cause.
As a matter of fact . . .
“The emerging consensus linking global warming to the increasingly
destructive power of hurricanes has been based in part on research
showing a significant increase in the number of category 4 and 5
hurricanes.” (AIT, p. 89)
• Gore refers to Webster et al. (2005), who found a
significant increase in the number of major hurricanes
during 1970-2004.
• Pat Michaels found that, in the Atlantic basin, Webster’s
trend disappears once data going back to 1940 are
included. See graphs below.
Exaggeration May Be Used
to Prove A Point
Gore suggested an "exact
fit" between the rise in
carbon dioxide levels and
the rise in temperatures
over a period of 650,000
years. Scientists
generally agree that there
is "a connection,"
between the two
phenomena, but claims
of an "exact fit" cannot
be established.
Exaggeration May Be Used
to Prove A Point
The judge cited a study by the Intergovernmental
Panel on Climate Change (IPCC), which concluded
that it was "very unlikely" that the Ocean Conveyer
would be shut down completely, although it might slow
Lack of Enough
Scientific Evidence
• Polar Bear Study
•The study is based on four
polar bears that were seen
floating offshore in Sep.
•They apparently drowned
after “an abrupt windstorm.”
Source: Monnett et al.
Lack of Enough
Scientific Evidence
An "Inconvenient Truth" claimed that
citizens of some low-lying inhabited
Pacific atolls "have all had to evacuate to
New Zealand" because of the inundation
of their islands caused by global
The judge said that he found no
evidence of "any such evacuation having
yet happened."
State Of Fear
• If we put the general public into a state of
fear, or panic, will they react more quickly?
• AIT uses alarmist viewpoints about
Antartica . . .
If the planet warms by 1.7˚C in the
next century, what is the change at
the poles?
“Each [green] splotch [identified by year] represents an ice
shelf the size of Rhode Island or larger that has broken up
since … [1978].” (AIT, pp. 181-182)
• “Size of Rhode Island” sounds very
big; hence very scary.
• Rhode Island is the smallest state.
• Since 1978, the Antarctic Peninsula
lost ice shelves totaling 4,825 square
miles. Source: Eurekalert, “Collapse of
Antarctic Ice Shelf Unprecedented,” 3
August 2005.
• For perspective, that is 1/55th the area
of Texas.
• Larson-B was about 1/220th the size of
Texas and 1/246th the size of the West
Antarctic Ice Sheet.
“Two new studies in 2006 showed overall volumes of ice in
Antarctica appear to be declining…”(AIT, p. 190)
• Gore alludes to Velicogna
and Wahr (Mar. 2006).
• The study shows that
volume is declining only
in the smaller West
Antarctic Ice Sheet. See
• A more recent study,
Wingham et al. (2006),
finds an overall increase
in Antarctic ice mass
during 1993-2003.
Velicogna and Wahr (2006). Ice
mass variations over the West
Antarctic Ice Sheet (red) and the
East Antarctic Ice Sheet (green).
How long until the WAIS vanishes beneath
the waves?
• “Most recession [of the WAIS]
occurred in the middle to late
Holocene in the absence of
substantial sea level or climate
• At the rate observed in the
1990s, “complete deglaciation
will take about 7,000 years.”
Source: Conway et al. 1999.
Graphic: Holocene grounding line
recession in the Ross Sea
Is AIT Only a
Political Game?
“On June 21, 2004, 48 Nobel Prize-winning scientists accused
President Bush and his administration of distorting science.” Gore
quotes them as criticizing Bush for “ignoring the scientific consensus on
critical issues such as global climate change.” (AIT, pp. 269-270)
• The June 21, 2004 letter from which Gore
quotes was an endorsement of John Kerry
for President.
• Science has become politicized
Carbon Emissions per Country
Population Growth
Sources include:
Al Gore’s An Inconvenient Truth:
A Skeptical Tour
By Marlo Lewis
Senior Fellow
Competitive Enterprise Institute
1001 Connecticut Ave. NW, Suite 1250
Washington, DC 20036
[email protected]