A balmy February in Vancouver has meant shipments of snow by the lorry load to deliver some winter to the Olympic Games. Several thousand kilometres away, an unusually snowbound Washington, DC, is just as bizarre. But a tale of these two cities does not make sound policy or sound science. Conservative pundits have crowed about the abundance of snow in Washington as disproving global warming, while environmentalists have pointed to the fact that climate change brings on drastic turns in weather. Either side may be correct. But by using discrete events to support their view, both sides weaken their argument.
Anecdotal evidence may add colour to dry statistics. It can humanise the death toll of an earthquake by telling the story of one human trapped inside the ruins or highlight the plight of a soldier locked in combat to illustrate the complexity of a large-scale war. But anecdotes cannot replace hard facts or scientific evidence when crafting policy. As one of the great concerns of our time, nothing is added to the climate debate by throwaway lines about Al Gore's whereabouts during a snowstorm or bobsleigh tracks outside Vancouver that may soon turn to water-slides.
The scientific community and a rigorously produced body of evidence must ultimately have the final say. After this week of snow politics melts away, the world must get back to evaluating the scientific evidence rather than interesting weather tales.