evidence: Claim that the Earth has cooled since Medieval or Roman times is contradicted by available data [...] Research does not show a Medieval Warm Period warmer than the present day [...] Earth’s mean temperature over the last 2,000 years shows two previous periods when temperatures were warmer than they are now; from 1–200 A.D., an epoch called the Roman Warm Period, and more recently the Medieval Warm Period from 900–1100 A.D.