The idea that global warming has slowed since 1997 is based on studies by the UK Met Office that used climate records from the HadCRUT4 dataset, which covers only 84 per cent of the globe.
Kevin Cowtan of the University of York and Robert Way of the University of Ottawa reconstructed ‘missing’ global temperatures using observations from satellites and surface data from weather stations and ships on the peripheries of the unsampled regions. They found a rate of warming since 1997 two and a half times greater than the Met Office’s. In the Arctic – a region excluded from the earlier study – warming is taking place at eight times the global rate.
‘There’s a perception that global warming has stopped but, in fact, our data suggest otherwise. But the reality is that 16 years is too short a period to draw a reliable conclusion. We find only weak evidence of any change in the rate of global warming,’ said Cowtan.
‘Changes in Arctic sea ice and glaciers over the past decade clearly support the results of our study,’ Way added. ‘By producing a truly global temperature record, we aim to better understand the drivers of recent climate change.’
This story was published in the January 2014 edition of Geographical Magazine