It is a persuasive image. Dubbed "the hockey stick" soon after it was first drawn, the graph shows the average temperature over the past 1000 years. For the first 900 or so years there is little variation, like the shaft of an ice-hockey stick. Then, in the 20th century, comes a sharp rise like a hockey stick's blade. The graph seems proof at a glance that we are drastically altering the climate of our planet. So it is not surprising that the Intergovernmental Panel on Climate Change (IPCC) chose to put the graph in the summary for policymakers in its 2001 report. Some of the scientists must have hoped that the image would become an icon of climate change.
展开▼
