Source: CO2 Science
Wang, T., Surge, D. and Mithen, S. 2012. Seasonal temperature variability of the Neoglacial (3300-2500 BP) and Roman Warm Period (2500-1600 BP) reconstructed from oxygen isotope ratios of limpet shells (Patella vulgata), Northwest Scotland. Palaeogeography, Palaeoclimatology, Palaeoecology 317-318: 104-113.
The authors write that “pre-industrial climate reconstructions during the mid to late Holocene provide the necessary information for understanding natural variation in the climate system prior to anthropogenic changes in the atmosphere, hydrosphere, and land use,” which information is a prerequisite for determining whether late 20th-century warming was natural or man-induced by the burning of fossil fuels. (more…)