Al continues by showing that there were large flood events in 2005. He also shows that there were more droughts in 2005 in areas not too far from the flooding. He says it’s because global warming is relocating the precipitation. As evidence of this he uses Lake Chad in Africa. Here again, the experts disagree and point to natural climate change. “Fluctuations are not new to Lake Chad. About 10, 000 years ago Lake Chad almost filled its present drainage basin, and spilled southwest out the Benue River to the Atlantic. In the last 1, 000 years, according to fossil evidence, the lake probably dried out a half-dozen times. (Most of its fish are river-adapted species.) Geologic data, climate data, historical accounts and reconstructions all indicate a higher long-term variability than the relatively short period we have actually measured.” Lake Chad
Next in the movie, Al Gore made several references to temperature increases in Alaska; he showed a picture of what he called “drunken trees.” He discussed how trucks that service the Alaskan pipeline can drive on permafrost roads fewer days of the year and he discussed how some homes and buildings are having structural problems because the permafrost that they were built on are melting. The graph below is a global map that shows warm weather relationships during El Nino winters. This graph shows that Alaska warms up during El Nino winters. So you would expect some melting of the permafrost in Alaska as if spring came earlier or fall came later. The weather patterns in Alaska are controlled by an ocean phenomenon called the Pacific Decadal Oscillation that is linked to ENSO.
The graph that Al uses to show the number of days that trucks can drive on the permafrost correlates with the ENSO phase shift explained above.
On the same point Al uses records from nuclear submarines that measured ice thickness, once again the ice begins to thin at the same time that the ENSO phase shift began.
The graph below is temperatures in Alaska for the since 1950. Note how temperatures changed in 1976
Al then starts to show how melting ice can accelerate water temperatures in the arctic. The ice reflects sunlight, but after the ice melts the ocean absorbs the sunlight that would otherwise be reflected. This is correct and is called albedo feedback.
Next, Al makes the point that melting sea ice is not good for polar bears. He claimed that polar bears were drowning for the first time according to a scientific study. What he failed to mention was that this was a one-time occurrence. The polar bears drowned because they were caught in a storm while swimming in the ocean. Polar Bears; Proceedings of the 14th Working Meeting of the IUCN/SSC Polar Bear Specialist Group, 20-24 June 2005, Seattle, Washington, USA
Al then presents how the Earth moves heat from the equator to the poles using air and ocean currents, this is correct. The temperature at the equator would change very little, and the average increase in temperature for the hemisphere is 1/8 of the temperature increase at the poles.
Al then turns up the scare tactic. Al explains what is known as the Younger Dryas Event. This happened at the end of the last glaciation. The ice sheet on North America was about a mile thick and extended down to a line from Seattle to Indianapolis to New York. Rather than slowly melting and running off, a large lake developed in the middle of the ice sheet about half of the size of Canada. When the ice dam at the edge of the lake burst a huge torrent of water ran off the continent and shut down the North Atlantic Drift current, which provides warmth to Europe and much of Asia. The result was an immediate return to ice age conditions for over a thousand years. With the exception that the Younger Dryas drained through the Mississippi rather than the St. Lawrence, Al did a good job showing this event and it’s effects. But then he moved the focus to the possibility that Greenland might repeat the same kind of abrupt climate changing event. He leaves the audience hanging and says he will get back to that subject in a minute. But I will not. There is no evidence that the ice sheet on Greenland could cause a similar event. This would require the center of Greenland to melt, form a large lake then dump into the Atlantic Ocean all at once, something that the surrounding ocean will not allow to happen. The warmer ocean water surrounding Greenland evaporates then precipitates on the center of Greenland building up the snow pack there. This is already happening and has been observed by NASA. History also tells us something about this not being able to happen. 125, 000 years ago the Earth was 3-5 degrees warmer that it is today (IPCC 2007) but ice cores from Greenland date several hundreds of thousands of years farther back. The lesson here is that Greenland could only melt slowly and not dump a huge amount of water into the ocean in a short period of time and create another Younger Dryas event.
After a brief political segment, Al continues with how species are being forced to adapting to climate change. He spoke of migratory birds in the Netherlands and Pine beetles and spruce trees in Alaska. This is true, but there is something you might learn here that Al did not intend to teach you. It is how climate change pushes evolution.
Al then speaks about how invasive species are coming into new areas and competing with native species. We have a similar problem here in Maine. Our lobster and crab industry is very important to our economy. We have two invasive species of crab, the European Green Crab and Asian Crab. But these crabs did not come here by walking across a global warming ocean bottom. They were brought here when they attached themselves to the bottom of boats hundreds of years ago. The same thing is happening to species all over the world; humans are moving them.
Al then gets into the health effects of global warming by claiming that global warming is spreading diseases and the vectors that carry them. He starts with the mosquito lines in Nairobi, Kenya and how the mosquitoes were moving to higher elevations because of a temperature increase. Mosquitoes will not move to higher elevations because of temperature increase. Mosquitoes live in areas where there is water; they are mostly found in shallow streams, ponds, or swampy areas. Another fact about mosquitoes that conflicts with Gore’s statement is that they don’t like to travel, but instead they stay about 1 mile within their breeding area.
The people who researched the malaria problem in Nairobi do not agree with Al.
“Medical researchers Amy Korman and Juma Makasa are investigating the outbreak. The research team suspected that the massive migration from the countryside was linked to the spread of malaria.