Comment on the paper “Characteristic time scales of decadal to centennial changes in global surface temperatures over the past 150 years “ by J.L. Le Mouël, F. Lopes and V. Courtillot First published: 14 October 2019 in Earth and Space Science

Yannis Cuypers (1) , Francis Codron (2) , Michel Crépon (2)

1 PROTEO - Processus et interactions de fine échelle océanique
2 VARCLIM - Océan et variabilité du climat

Based on Singular Spectral Analysis (SSA) analysis of global earth surface temperature and solar activity (sun spots) Le Mouël et al (2019) suggest that the variability in Earth surface temperature observed since 1850 is natural and controlled by the Sun. We we cannot agree with their conclusions for several reasons: the lack of compelling results from the Fourier spectra and SSA estimates which are provided without confidence intervals, the small radiative forcing associated with the sunspot variability and finally the simple evidence that the slowly varying components of the temperature and sunspots time show opposite trends in the last 30 years.

Domaines: Géophysique [physics.geo-ph]

Yannis Cuypers, Francis Codron, Michel Crépon. Comment on the paper “Characteristic time scales of decadal to centennial changes in global surface temperatures over the past 150 years “ by J.L. Le Mouël, F. Lopes and V. Courtillot First published: 14 October 2019 in Earth and Space Science. Earth and Space Science, 2021, 8 (4), pp.e2020EA001298. ⟨10.1029/2020EA001298⟩. ⟨hal-03171976⟩