This article summarizes my public presentation of the book The Frontier of Climate Science: Solar Variability, Natural Cycles and Model Uncertainty. The book reviews the main current open issues in climate science: the questionable near-total attribution of post-1850 warming to anthropogenic causes alone, the use of unrealistic emission scenarios (SSPs), the wide uncertainty range in equilibrium climate sensitivity, the gap between satellite and surface temperature records, the failure of models to reproduce past warm periods (the Holocene Thermal Maximum, the Roman Warm Period, the Medieval Warm Period), and the potentially underestimated role of solar variability mediated by cosmic rays and cloud cover. Building on these observations, empirical modelling is proposed based on astronomically-derived cycles – linked to the gravitational interactions among the Sun, the Moon, and the major planets – and that reproduces the observed global temperature record with greater fidelity. This yields a substantially lower estimate of climate sensitivity to a doubling of CO2 (1-1.5 °C) than that used in CMIP models, with important implications for climate policy: moderate warming over the course of the 21st century would be manageable primarily through adaptation strategies, rather than through costly net-zero emission-reduction policies.
