Global cooling trend over last 2000 years ended at end of 19th century

Reconstructing spatial and temporal patterns of climate variability is important for understanding the dynamics of the global climate sys­tem, and to distinguish anthropogenic impacts from the background range of natural variability. While previous studies have tended to focus on global-scale reconstructions of past temperature change, a new study examines temperature evolution at a continental-scale over the last 2000 years. Published online in Nature Geoscience, a large consortium of scientists known as the PAGES organization coordinated researchers and data across all continental regions except Africa, which unfortunately had a lack of data.
Temperatures were reconstructed through a variety of proxy methods, including tree rings, corals, pollen, sediment, ice cores and stalagmites. According to the data, temperature changes and fluctuations occurred during different times on different continents, but overall, Earth's land masses were generally cooling until the late-19th Century, when average temperatures started to increase. The most recent 30 year interval in the study, from 1971 to 2000, was the warmest for almost 1400 years. This study adds more weight to the overwhelming body of scientific evidence that recent global climatic changes are anthropogenically driven, a point that is still hotly debated in the public and political arena. It also highlights the need for African countries to fill in the data gaps and contribute to global climate studies.

PAGES 2k Network (2013). Continental-scale temperature variability during the past two millennia. Nature Geoscience. DOI: 10.1038/ngeo1797.