Professor Jones also conceded the possibility that the world was warmer in medieval times than now – suggesting global warming may not be a man-made phenomenon.
And he said that for the past 15 years there has been no ‘statistically significant’ warming. …
And he said that the debate over whether the world could have been even warmer than now during the medieval period, when there is evidence of high temperatures in northern countries, was far from settled.
Sceptics believe there is strong evidence that the world was warmer between about 800 and 1300 AD than now because of evidence of high temperatures in northern countries.
But climate change advocates have dismissed this as false or only applying to the northern part of the world.
Professor Jones departed from this consensus when he said: ‘There is much debate over whether the Medieval Warm Period was global in extent or not. The MWP is most clearly expressed in parts of North America, the North Atlantic and Europe and parts of Asia.
‘For it to be global in extent, the MWP would need to be seen clearly in more records from the tropical regions and the Southern hemisphere. There are very few palaeoclimatic records for these latter two regions.
‘Of course, if the MWP was shown to be global in extent and as warm or warmer than today, then obviously the late 20th Century warmth would not be unprecedented. On the other hand, if the MWP was global, but was less warm than today, then the current warmth would be unprecedented.’
