An Inconvenient Truth, By Al Gore

Like all effective horror movies, An Inconvenient Truth has a slow build-up; in fact, the setting is about as banal as it gets: a public lecture given by a well-known member of the political establishment, former US Vice President Al Gore. The hair-raising message he relates is also beginning to become as clichéd as last year’s favourite psychopath: inhabitants of industrialised nations are collectively destabilising Earth’s climate. But as the discerning movie buff knows, it all comes down to delivery. And Gore is a master of the unsettling plotline.

It all started, he tells his audience, when one of his professors at Harvard University, Roger Revelle, presented in class the now iconic serrated curve describing the concentration of atmospheric CO₂ over time. This curve is also known as the Keeling Curve in honour of Charles Keeling, who took the CO₂ measurements from 1958 onwards. He established that in the summer, when the plants in the northern hemisphere are busy fixing CO₂, its atmospheric levels decrease; during the northern winter, they increase. So far, this is reassuringly in agreement with high-school biology.

However, the unease starts creeping in as we realise that, in the summer, the curve almost never returns to its previous minimum but levels off at a slightly higher point. The rate of this overall increase looks tiny, but a plot of atmospheric CO₂ and temperature over the past 650 000 years reveals that the two quantities are tightly correlated. And then comes the crunch: on the scale of the past 650 000 years, the increase in CO₂ since World War II is extremely rapid. More disquieting still, the current level of atmospheric CO₂ is unprecedented over the past 650 millenia.

So what? If it gets a bit hotter, crank up the air conditioner, get a beer from the fridge and rent another gory movie. The trouble is, Gore points out, that as the ice at the poles melts due to global warming, less sunlight is reflected by the polar glaciers, which creates a positive feedback cycle of warming at the poles. The effects of this are visible all around us: of the 21 hottest years since 1860, 20 occurred over the past quarter of a century. The heat wave of summer 2003 caused thousands of deaths in Europe. Hotter summers are correlated with stronger cyclones. Gore punctuates his slide show with footage taken in 2005 when Hurricane Katrina devastated New Orleans.

The ex-Vice President is not a scientist (he trained as a lawyer) and his presentation is a work of advocacy aimed at a lay audience. Having said that, unless you are an earth scientist, you will probably find something new and stimulating in what he is saying.

This is particularly true if you read the book of the same name. I found the film moving, but the book – with its carefully presented charts and statistics – more rewarding. Being rich today means rich in fossil fuels. It is no coincidence that the leaders of the USA and Russia, and the previous Chancellor of Germany, are closely allied with oil and gas companies. The carbon consumers in the G8 countries are causing environmental change that has its gravest effects on the poorest countries. This thought alone should rouse us enough to act upon Gore’s inconvenient truth.

Details

Book

Publisher: Bloomsbury Publishing

Publication year: 2007

ISBN: 9780747590965

DVD

Publisher: Paramount Home Entertainment

Release year: 2006