Additional info from the Union of Concerned Scientists
Climate science contrarians have twisted a statement by Phil Jones, director of the University of East Anglia's Climatic Research Unit, made during a British Broadcasting Corporation (BBC) interview.
When asked, "Do you agree that from 1995 to the present there has been no statistically significant global warming?" Jones answered, "Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12°C per decade) is positive, but not significant at the 95 percent significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods."
Contrarians claim that Jones said the Earth is not warming. In fact, Jones answered a very narrow question about how much temperatures have increased during the past 14 years, and only the past 14 years. Over this very short time period, human-induced warming has caused the planet to remain quite hot compared to its average for the past century. But with only 14 years of data, it is hard to detect a high level of significance for any trend.
By contrast, data collected over the past 100-plus years show an unmistakable warming trend. Later in the interview, Jones said, "I'm 100-percent confident that the climate has warmed." On the question of whether or not humans are contributing to that warming, Jones added, "I would go along with [Intergovernmental Panel on Climate Change] Chapter 9: There's evidence that most of the warming since the 1950s is due to human activity."
Adapted from © Union of Concerned Scientists