Lead author Professor Dr Jan Esper of Johannes Gutenberg University in Mainz said: ‘We found that previous estimates of historical temperatures during the Roman era and the Middle Ages were too low.
‘This figure we calculated may not seem particularly significant, however it is not negligible when compared to global warming, which up to now has been less than 1 deg C.’
In general the scientists found a slow cooling of 0.6C over 2,000 years, which they attributed to changes in the Earth’s orbit which took it further away from the Sun.
The study is published in Nature Climate Change.
It is based on measurements stretching back to 138BC.
The finding may force scientists to rethink current theories of the impact of global warming
evidence keeps mounting against man made climate change, wonder how all the chicken littles will try to spin this.