The 31-year long total solar irradiance (TSI) climate data record links accurate current solar variability measurements with proxies allowing historical reconstructions that provide inputs to modern global climate models used to determine terrestrial climate sensitivity to solar forcing. I will show measured short-term variability in TSI, which is the primary driver of Earth’s climate by nearly four orders of magnitude. I describe the measurement accuracies and stabilities required to establish benchmark solar irradiance values and to detect long-term trends in TSI, such as those occurring during the Maunder Minimum. I review recent updates to historical solar reconstructions and their effects on climate model solar forcing sensitivities.
