Before we embark on drastic plans to combat climate change, we must be sure of the factsby Roddy Campbell / February 24, 2010 / Leave a comment
Published in March 2010 issue of Prospect Magazine
An automatic weather station being installed on Butler Island, Antarctica
The belief that man is warming the Earth’s climate via greenhouse gas emissions is supported by evidence showing a modest increase in global temperatures over recent decades. But what is the scale of these increases, and are they in any way abnormal? To find out, we need an accurate record over a long period. This is where the University of East Anglia’s Climatic Research Unit (CRU) comes in, and why the “climategate” scandal over its leaked emails matters so much.
The CRU is one of the world’s leading climatic research bodies. Its scientists, along with the Met Office’s Hadley Centre, build and maintain the world’s temperature record. This may sound easy, especially as the figures they produce always seem precise: in 2007 the Intergovernmental Panel on Climate Change put warming over the past 100 years at exactly 0.74°C. But tracking such tiny temperature changes is tricky—even over the last century when we have had decent thermometer coverage. Do you measure highs, lows or averages? Should readings come from Siberia, Antarctica or Australia—and, if all of them, how do you weight the results for a global average? By land area? What about seas?