‘Therefore it is impossible to conclude from our analysis which of 2014, 2010, or 2005 was actually the warmest year… the Earth’s average temperature for the past decade has changed very little.’
Scientists disagree over its significance, but there is little doubt that the rapid warming of the 1980s and early 1990s has slowed – although greenhouse gas emissions have surged.
Bob Ward, of the Grantham Institute on Climate Change, said the new figures showed the notion that global warming had ‘stopped’ was a ‘myth’, although it had ‘temporarily slowed’. Since 1951, he added, the long-term trend was for warming of 0.12C per decade, and in his view, it would ‘pick up again unabated’ if emissions continued to rise.
However, if the long-term rate is 0.12C per decade, this would mean the world would be 1C or so warmer by the end of the century, not 4C-5C as some have claimed.
Climate sceptics insisted that the new figures showed the warming ‘pause’ had continued. Dr David Whitehouse, of the Global Warming Policy Forum, said ‘there has been no statistically significant warming trend since 1997’ – because the entire increase over this period was smaller than the error margin.
Dr Ed Hawkins, associate professor of climate science at the University of Reading, said the past 15 years had seen a slightly slower rate of warming.
But he added: ‘You have to take a longer view, because 15 years is too short a period. We expect natural fluctuations, volcanic eruptions and changes in solar output to sometimes slow and sometimes increase warming rates.’