Former Vice-President Al Gore uses a cartoon frog at one point to illustrate the dangers of global warming in the movie An Inconvenient Truth (directed by Davis Guggenheim, now playing). First, the frog is thrown into a beaker with hot water and promptly jumps out. However, when a big hand puts the frog into cold water and the invisible torturer slowly turns up the heat under the beaker, the frog just sits there, oblivious to its fate. For Mr. Gore, this is a metaphor for humankind dealing with problems ahead: unless shocked into action, we will just sit in the beaker of warming water until it is too late. Mr. Gore takes it upon himself to throw us into hot water and jolt us to do something, so we don’t suffocate ourselves in a greenhouse or freeze to death in the next ice age.

The movie is structured around a slideshow, interspersed with personal anecdotes. First, Mr. Gore makes sure the viewers understand what is happening to our atmosphere. He shows us how atmospheric temperature and CO₂ concentrations moved up and down in lockstep over the millennia. He only very briefly mentions the methods used to infer these temperatures from hundreds to millions of years ago, such as the density of tree rings or from the ratios of oxygen isotopes in the air trapped in Antarctic ice. Then he vividly demonstrates how literally off the charts the current CO₂ levels are, and where they are going to be in fifty years if the current trend continues. He tells us up front that the relationship between atmospheric CO₂ levels and temperature is a complex one, but one is easily convinced that if the temperature follows the CO₂ levels as it did over the ages, we are going to be buying far fewer fur coats.

It won’t be just the winter garment industry that will suffer. Mr. Gore opens his little book of horrors to warn us of what may come and points out to us what is already happening. Glaciers are disappearing at ever higher rates, and soon the Glacier National Park will have glaciers only in its name. The same is true for Himalayan glaciers, but here the potential impact of their disappearance is more serious because millions of people depend on them as their source of drinking water.

According to Mr. Gore, the elevated temperatures are already leading to the change of balance in ecosystems and propagation of various invasive species and disease vectors—he cites the spread of the West Nile virus, SARS, and avian flu as a direct consequence of warming in the past twenty-five years. Where the movie gets on yet thinner ice is when Mr. Gore attributes the devastating strength of Hurricane Katrina last year to global warming, in particular increased water temperature in the Gulf of Mexico, despite the lack of scientific evidence to back this often voiced claim¹.

Nowhere are the dangers of climate change and the complexities of its predictions more apparent than in the effect of melting polar ice caps. The movie shows convincing imagery demonstrating the extent of the melting of glaciers covering Antarctica and Greenland. The first and most obvious effect will be felt by people living in the coastal areas. In a relatively moderate scenario used by Mr. Gore, melting of Greenland ice cover would lead to the rise of sea levels by 20 ft, or 6.1 m (the third report of the Intergovernmental Panel on Climate Change predicts sea levels to rise 1.1 to 7.7 m by 2100²). You can check whether your Manhattan real estate would be affected on a Web site which combines Google Maps with NASA elevation data³. Flooded coastal areas are only part of the story. The extra freshwater provided by melting will perturb ocean currents, which in turn will lead to changes in the patterns of heat distribution around the globe. The rising sea levels, droughts in some parts of the globe, and floods in others will lead to the displacement of millions of people, cause famine, and bring about social upheaval as a result of mass migrations. This is when global warming will cease to be an inconvenience and will start to touch everybody living on this planet. Mr. Gore already sees these societal effects manifesting themselves in sub-Saharan Africa, particularly in Darfur, where the droughts aggravate the tragic conflict there.

The signs of global warming are certainly troubling, but is Mr. Gore the right person to pass the word? I doubt that this documentary will be a hit in the White House screening room for at least two more years, or in the parts of the country that do not share the worldview and values Mr. Gore is perceived to represent. Mr. Gore proudly shows his record as a politician and does not hide his disdain for the current tenants of the house which he feels he was entitled to occupy. However, he wins over the viewers with his sometimes self-deprecating sense of humor and touching insights into his private life. He also distances his persona from the message he is eager to convey by relying on his cartoon alter ego⁴.

Mr. Gore warns us against a possibly gloomy future, but the message of the movie is essentially optimistic. After all, the (cartoon) frog mentioned earlier gets rescued from the heating pot of water, and we see it enjoying sunshine and a drink while resting in a beach chair. Regardless of the failure of the federal government of the USA to ratify the Kyoto Treaty, which requires its signatories to decrease greenhouse gas emissions, many cities and states in the US have voluntarily adopted its principles. To me, this shows a remarkable capacity of this society for self-regulation despite the shortsightedness of some politicians who are unable to see beyond the span of the electoral cycle and to resist various lobbies. The marketplace will also eventually contribute to the efforts to minimize greenhouse gases, as insurers start passing the costs of global warming repercussions onto their clients.

Mr. Gore presents a list of measures and new technologies, such as higher fuel efficiency standards for cars, development of wind and solar energies, and carbon sequestration. These are insufficient on their own, but when combined will lead to significant reduction of greenhouse gas emissions. Conspicuous by its absence from this list was nuclear energy, which at present already accounts for twenty percent of electricity produced in the USA and does not contribute to global warming. It looks like the move of an experienced politician to choose not to rile his constituents with an unpopular solution, but he should have told the inconvenient truth: in trying to rein in global warming, we will need all the tools available to us. Mr. Gore says that for him global warming is not a political issue, but a moral issue. I would add that, for mankind, it may be an issue of survival.

References:

¹ http://wind.mit.edu/~emanuel/anthro2.htm

² http://www.grida.no/climate/ipcc_tar/

³ http://flood.firetree.net/?ll=40.7634,-73.9531&z=1&m=6

⁴ http://www.youtube.com/watch?v=5BjrOi4vF24&feature=Views&page=1&t=m&f=b