Long-term natural variability and 20th century climate change

• DOI: 10.1073/pnas.0908699106
• Publication Date: 2009-09-15T01:48:54Z
• Authors: Kyle L. Swanson; George Sugihara; Anastasios A. Tsonis
• Keywords: Climate system; Climate commitment; Mean radiant temperature; Climatic variability

Global mean temperature at the Earth's surface responds both to externally imposed forcings, such as those arising from anthropogenic greenhouse gases, well natural modes of variability internal climate system. Variability associated with these latter processes, generally referred long-term variability, arises primarily changes in oceanic circulation. Here we present a technique that objectively identifies component inter-decadal global attributable variability. Removal hidden actual observed record delineates forced signal, which is monotonic, accelerating warming during 20th century.