Reconstruction of the Interannual to Millennial Scale Patterns of the Global Surface Temperature

摘要: Climate changes are due to anthropogenic factors, volcano eruptions and the natural variability of Earth’s system. Herein global surface temperature is modeled using a set harmonics spanning from inter-annual millennial scales. The model supported by following considerations: (1) power spectrum evaluations show 11 spectral peaks (from sub-decadal multi-decadal scales) above 99% confidence level known uncertainty; (2) coherence analysis between independent periods 1861–1937 1937–2013 highlights at least eight common frequencies 2- 20-year periods; (3) paleoclimatic reconstructions during Holocene present secular oscillations. oscillation was responsible for cooling observed Medieval Warm Period (900–1400) Little Ice Age (1400–1800) and, on average, could have caused about 50% warming since 1850. finding implies an equilibrium climate sensitivity 1.0–2.3 °C CO2 doubling likely centered around 1.5 °C. This low radiative forcing agrees with conclusions recent studies. Semi-empirical models 1000 A.D. developed 13 identified (representing system) climatic function derived Coupled Model Intercomparison Project 5 (CMIP5) ensemble mean simulation greenhouse gas—GHG, aerosol, contributions) scaled under assumption harmonic evaluated data 1850 2013 test its ability predict major patterns in record 2014 2020. In short, medium, long time scales semi-empirical predict: maxima 2015–2016 2020, which confirmed 2014–2020 record; relatively steady 2000 2030–2040; 2000–2100 projected 1 reconstructs accurately historical hindcasts proxy medieval period better than that unable simulate Period.