What’s the Worst that Could Happen? A Rational Response to the Climate Change Debate by Greg Craven
Simon Singh on a rational look at climate change
I have to admit to being a fan of Greg Craven, the science teacher from Oregon who became a YouTube sensation when his videos about climate change attracted almost ten million viewers. The video entitled "The Most Terrifying Video You’ll Ever See" has now spawned a book which follows exactly the same format – Craven does not tell you what to think about climate change, but rather how to think, and in particular how to think rationally and critically about risk.
The book retains the informality, quirkiness, wit and charm of a homemade YouTube video, because Craven writes as if he is casually chatting to his reader. Those already familiar with Craven’s video will rapidly adjust to his writing style, but for others it may require some time to get used to his convivial tone.
For Craven, the key question is not “Should I believe global warming is true?”, because nobody knows the answer for sure. Instead, the key question is “What should I do right now, given the risks and uncertainties about global warming?” At the end of the book, Craven explains how he personally answers the latter question, but the bulk of the book is aimed at giving us the tools necessary to find our own answer.
The central tool is the decision grid, which consists of two rows and two columns. The rows are marked “global warming is true” and “global warming is false”, and the columns are marked “take significant action now” and “take no action now”. The goal is to then fill in the boxes with various benefits and harms. The first box, “taking no action if global warming is false”, has no benefits as there was no threat to be avoided and there are no costs because we rightly took no evasive action. By contrast, “taking action if global warming is false” has various negatives, because taking action would have harmed our economy for no good reason. The most important boxes in the grid are the “taking action if global warming is real”, which results in some damage to our economy in the short term and major benefits to humanity in the longer term, and “taking no action if global warming is real”, which results in global catastrophe.
Like all good teachers, Craven holds our hands as he walks us through his decision grid, but he also expects us to do our homework and to think for ourselves. The toughest aspect of the decision grid is assessing the probability that global warming is real and what the impacts will be. Craven asks us not to believe him or anybody else in particular, but rather offers a series of lessons that allow us to conduct our own analyses, while also confronting and accounting for our own biases.
My favourite lesson concerned Craven’s credibility spectrum, which asks us to list in order of reliability all the sources that we might consider when making a decision about climate change. Although Craven repeatedly begs us to create our own spectrum, he does give a few examples that might appear on his credibility spectrum in order of reliability.
At the top are the professional societies, such as the National Academy of Sciences (NAS), which is made up of America’s most eminent scientists. The NAS and the science academies of other industrialised nations issued a joint statement in 2005 claiming that “the threat of climate change is clear and increasing”, and called on governments to take immediate action.
Next on Craven’s credibility spectrum come sources that contradict their normal bias, such as the Pentagon, which is not usually known for its touchy, feely attitude to the environment. In 2003, it published a study titled “An Abrupt Climate Change Scenario and Its Implications for United States National Security: Imagining the Unthinkable”, which envisaged a potentially cataclysmic future. It contained lines such as: “With inadequate preparation, the result could be a significant drop in the human carrying capacity of the Earth’s environment.” America’s National Intelligence Assessment and Center for Naval Analyses have taken a similarly gloomy view of the impact of climate change.
Craven also places the US Climate Action Partnership (USCAP) in this part of the credibility spectrum, because it consists of a collection of companies (e.g., BP America, Shell, ConocoPhillips, Ford Motor) that have championed the need for action. In 2007, USCAP published a report calling for government-imposed mandatory carbon emissions caps on their own industries. Hard-nosed industrialists responsible for a large fraction of our past carbon emissions pointed out: “We know enough to act on climate change” and “There must be reasonable and serious debate about the solutions, but debate cannot be a substitute for action.”
Craven’s book is an excellent primer on clear thinking in general and how to think about climate change in particular. But don’t take my word for it, track down Craven’s original YouTube video. Treat it as a summary of the book and then decide whether or not to buy it. I suspect that you, like me, will be won over by his charm, inventiveness and insight.
What's the Worst that Could Happen? is published by Perigee