Some convenient notes (please remember that I wrote these seven years ago -- my views have changed a bit, in response otonewer evidence, since then -- but this reflects teh sate of evidence I cojld find at the time):
These comments follow approximately the order that the relevant claims (in italics) are made in the film. Some of the falsehoods are probably carelessness, some probably result from ignorance, and some appear to be deliberately misleading:
The most vulnerable part of the Earth is the atmosphere. Debatable. Fresh water supplies, particularly groundwater, are probably at least as vulnerable, if not more so.
The mechanism of the Greenhouse Effect is that there is a layer of atmosphere that reflects the heat and that CO2 emissions thicken this layer, making it more reflective. Utter rubbish: this is not how the Greenhouse Effect works; there is no “layer” of CO2.
Revelle's 1958 measurements were the first measurements made of atmospheric CO2. Utter rubbish: CO2 measurements had been made before 1900.
Gore makes a big issue of how Revelle influenced him. However, Professor Revelle co-authored an article in the journal of the Cosmos Club in Washington, DC in 1991 which concluded, “The scientific base for a greenhouse warming is too uncertain to justify drastic action at this time.” Revelle died shortly after the article appeared. This conclusion dismayed Gore, whose staff worked behind the scenes to spread the rumour that Revelle's co-authors had taken advantage of a senile old man. Gore tried to have Revelle's name taken off the article. This fiasco ended with a lawsuit in which a Harvard professor who had conferred with Gore's staff formally apologized for his false insinuations.
An implication that the reduction in snow on Kilimanjaro is due to global warming. Nonsense. It is due to a reduction in precipitation, so the snow that melts (as it has always done) is not being replaced as fast as it melts.
Dramatic footage of glaciers collapsing into the Sea used to exemplify global warming. Misleading: as Dr. Boris Winterhalter, professor in marine geology at the University of Helsinki, states, "The breaking glacier wall is a normally occurring phenomenon which is due to the normal advance of a glacier. In Antarctica the temperature is low enough to prohibit melting of the ice front, so if the ice is grounded, it has to break off in beautiful ice cascades. If the water is deep enough icebergs will form." Dr. Wibjorn Karlen, emeritus professor in the Department of Physical Geography and Quaternary Geology at Stockholm University, admits, "Some small areas in the Antarctic Peninsula have broken up recently, just like it has done back in time. The temperature in this part of Antarctica has increased recently, probably because of a small change in the position of the low pressure systems." But Karlen clarifies that the 'mass balance' of Antarctica is positive - more snow is accumulating than melting off. As a result, there is an increase in the 'calving' of icebergs as the ice dome of Antarctica is growing and flowing to the oceans. When Greenland and Antarctica are assessed together, "their mass balance is considered to possibly increase the sea level by 0.03 mm/year - not much of an effect," Karlen concludes.
Gore claims that, simply by looking at Antarctic ice cores with the naked eye, one can see when the American Clean Air Act was passed. This is either fantasy or a deliberate attempt to mislead. The naked eye cannot detect changes of the order of parts per billion to chemicals in ice. Furthermore, air over the USA doesn’t even circulate to the Antarctic before mixing with most of the northern, then the southern, hemisphere air and this process takes decades. Dr. Ian Clark, Professor of Earth Sciences at the University of Ottawa, Canada, has demonstrated that even far more significant events, such as the settling of dust arising from the scouring of continental shelves at the end of ice ages, are undetectable in ice cores by an untrained eye.
Gore claims, "Starting in 1970, there was a precipitous drop-off in the amount and extent and thickness of the Arctic ice cap." Misleading: The survey that Gore cites was a single transect across one part of the Arctic basin in the month of October during the 1960s when we were in the middle of the cooling period. The 1990 runs were done in the warmer month of September, using a wholly different technology. In a paper published in 2003 by University of Alaska professor Igor Polyakov, he shows that the region of the Arctic where rising temperature is supposedly endangering polar bears showed fluctuations since 1940 but no overall temperature rise. As Karlen states, "For several published records it is a decrease for the last 50 years." Dr. Dick Morgan, former advisor to the World Meteorological Organization and climatology researcher at University of Exeter, U.K. gives the details, "There has been some decrease in ice thickness in the Canadian Arctic over the past 30 years but no melt down. The Canadian Ice Service records show that from 1971-1981 there was average, to above average, ice thickness. From 1981-1982 there was a sharp decrease of 15% but there was a quick recovery to average, to slightly above average, values from 1983-1995. A sharp drop of 30% occurred again 1996-1998 and since then there has been a steady increase to reach near normal conditions since 2001."
The graphs showing correlation between CO2 and temperature over the last four Ice Ages. Gore conceals the fact that the CO2 changes lagged behind the temperature changes by the order of 800 years, a time represented by a distance that is a fraction of the thickness of the lines of the graphs that Gore presented (the graph lines were equivalent to about 2,500 years thick).
The claim that we now have the highest CO2 ever. Err, no: this is at odds with what paleoclimatologists tell us about Earth's early climate. Also, Gore conveniently ignores the fact that his graphs demonstrate that temperature has not followed the recent rise in CO2 concentration in the atmosphere.
Gore makes a big issue of the increased incidence of hurricanes in the Gulf of Mexico. 1900, 1926 and 1935 as the years in which the most intense hurricanes were recorded in the US. Gore also conceals the fact that the only ocean basin to show an increase in hurricanes in recent years is the North Atlantic. As hurricane specialist Dr. Tad Murty, adjunct professor of Earth Sciences at University of Ottawa, states, “In all other six ocean basins, where tropical cyclones occur, there is either a flat or a downward trend. The feeling among many meteorologists is that it has to do with the North Atlantic Oscillation, which is now in the positive phase and will continue for another decade or so.” Gore also ignores US hurricane experts, such as that of Max Mayfield, Director of the National Hurricane Center in Miami, who has stated that global warming has nothing to do with the recent increase in hurricane frequency in the North Atlantic.
Hurricane Katrina grew “stronger and stronger and stronger” as it passed over the Gulf of Mexico. Nonsense. It was a category 5 hurricane over the ocean and had declined to category 3 by the time it made landfall.
Gore's rainfall graph. Gore seems to ignore the fact that it is 1992 that shows the highest rainfall in his own graph.
Gore makes a big issue of 37” of rain at Mumbai in one day of the 2005 monsoon. Irrelevant: Gore conceals the fact that storms like this are not unusual, even in the USA. In one day in 1921, Thrall, Texas had 38”; in 1979, Alvin, Texas had 43 inches over a 24-hour period.
Gore demonstrates how heating can draw moisture from the soil, leading to desertification. He ignores the obvious conclusion that heating, by causing loss of photosynthetic plants, can lead to an increase in CO2 .
Recent ice shelf cracking. See above, but Gore also ignores the ice shelf cracking of 6000 years ago.
Gore notes that permafrost is melting in parts of Alaska and Siberia. The temperatures in central Siberia are thought to have increased by 3 degrees Celsius over the past 40 years. This not only causes engineering and infrastructure problems, but might also release even more carbon dioxide into the atmosphere as once frozen organic matter begins to decompose. But this warming is by no means unprecedented. A Russian study in 2004 found that the average temperatures in Siberia during the Holocene Climatic Optimum around 6000 years ago increased by 3º to 9º Celsius in the winter, and by 2º to 6º Celsius in the summer. 6000 years ago, the entire Arctic was warmer than it is now!
Gore states, and his graphic shows, that >90% of incident sunlight in the Arctic would be absorbed by the ocean if the ice cap melted. Nonsense: the shallow angle of the incident sunlight would mean that far more than 10% would be reflected out into space.
Polar bears drowning. Cutesy graphic, probably based on the 2002 WWF warning that global warming was endangering polar bears. Yet, the WWF report itself found that most bear populations are either stable or increasing (see page 9 of the report). Polar bears obviously survived when Arctic temperatures were even warmer 6000 years ago.
Gore claims that the Mountain Pine Beetle (MPB) is an “invasive exotic species” that has become a plague due to fewer days of frost. Rob Scagel, a forest microclimate specialist, states, “The MPB is a species native to this part of North America and is always present. The MPB epidemic started as comparatively small outbreaks and, through forest management inaction, got completely out of hand.”
Gore claims that Nairobi and Harare were founded just above the mosquito line to avoid malaria and how the mosquitoes are now moving to higher altitudes. Completely false. Malaria was documented at an altitude 2500m in the early 20th Century; Nairobi and Harare are at altitudes of about 1500m. The current altitudes of malaria are lower than those recorded 100 years ago.
Gore tries to implicate global warming in Avian 'flu, West Nile Virus, etc. False. Outbreaks of 'flu are not generally associated with higher temperatures! West Nile Virus is a mosquito-borne virus that first appeared in New York City in 1999, having arrived from Israel. It is quickly spreading across the country carried by birds on which mosquitoes feast. The Centers for Disease Control map of WNV and related viruses shows that WNV is not, and never was, confined to tropical regions. WNV took hold in the USA not because of increases in global temperatures, but because, like malaria, cholera, and dengue before it, an appropriate carrier finally made it across the Atlantic. None of the 30 or so “new diseases” to which Gore refers is attributable to global warming
Gore makes a big deal about species loss. This is a very serious issue, but the great majority of it is due to habitat destruction by logging, strip-mining, urban expansion, etc., not global warming. Gore focuses attention away from the true causes.
Evacuation of South Pacific islanders to New Zealand owing to sea level rise. Not according to Dr. Chris de Freitas, climate scientist, associate professor, University of Auckland, New Zealand, who states: ”I can assure Mr. Gore that no one from the South Pacific islands has fled to New Zealand because of rising seas. In fact, if Gore consults the data, he will see it shows sea level falling in some parts of the Pacific.”
Gore uses 1992 as his “base year” for Greenland ice melt. 1992 was exceptionally cold in Greenland and the melt area of ice sheet was exceptionally low due to the cooling caused by volcanic dust emitted from Mount Pinatubo. If, instead of 1992, Gore had chosen for comparison the year 1991, one in which the melt area was 1% higher than in 2005, he would have to conclude that the ice sheet melt area is shrinking and that perhaps a new ice age is just around the corner.
Scientists persecuted for going against the grain. Scientists who stand up against Gore's CO2 lobby are now being persecuted!
Gore quotes that people do not understand things if their salary depends on their not understanding those things. Gore's salary depends on his “not understanding” that CO2 might not be as big a player in climate change as he portrays.
Gore's technological fixes for CO2 emissions. Most of these are laudable for their own sakes. However, they will only affect climate change if Gore is correct in his contention that CO2 is almost solely responsible for climate change. Given that the evidence is that Gore is wrong, his technological fixes will not work.
The aphorisms at the end of the film. One of these gives the game away: “Reduce dependence on foreign oil.” “Foreign” oil produces no more CO2 than does Texan oil. The real issue for the likes of Gore is clearly oil security, not global warming!