The UN's IPCC claims that modern global warming is "unprecedented" continues to be robustly discredited by the newest scientific research - another peer reviewed study confirms that the Medieval Warming (plus the Roman and Minoan) periods had significantly warmer summers (Kamchatka, Siberia) than our current period, which has atmospheric CO2 levels exceeding 350 ppm
(click on images to enlarge - source)
Read here. Scientists from Europe and Russia reconstructed temperatures from a Kamchatka Peninsula sediment core that contained chironomids. As the chart on the right depicts, the scientists determined that there were extended periods, well before CO2 atmospheric CO2 levels of 350 ppm and greater, when summer temperatures were well above modern temps.
"A paper published in Quaternary Science Reviews reconstructs Arctic temperatures in Kamchatka, USSR over the past 4,500 years and finds the highest reconstructed temperatures were about 3.8°C warmer than modern temperatures. The authors find "the highest reconstructed temperature reaching 16.8 °C between 3700 and 2800 years before the present," about 3.8°C above "modern temperatures (∼13 °C)." In addition, the data shows temperatures between 2500 - 1100 [during the Medieval and Roman warming periods] were about 1-2°C above modern temperatures of ~13°C." [Larisa Nazarova, Verena de Hoog, Ulrike Hoff, Oleg Dirksen, Bernhard Diekmann 2013: Quaternary Science Reviews]
Additional climate-history and peer-reviewed articles. Other historical-temperature charts.