Matt Ridley's latest Wall Street Journal column is on the medieval warm period.
I consulted a database of papers collated by the climate-skeptic website CO2Science.org, run by the Center for the Study of Carbon Dioxide and Global Change, a nonprofit research center in Tempe, Ariz. The database contains numerous published studies of isotopes and other indicators in caves, lake sediments and other samples from Chile, New Zealand, South Africa and Antarctica that find the MWP warmer than today. Two Antarctic studies, for instance, concluded that current warming "is not yet as extreme in nature as the MWP" and that "the present state of reduced ice on the western Antarctic Peninsula is not unprecedented." A far smaller number of studies, such as one from Lake Tanganyika, found the MWP cooler than today.