Total solar irradiance during the Holocene

For the first time a record of total solar irradiance covering 9300 years is presented, which covers almost the entire Holocene. This reconstruction is based on a recently observationally derived relationship between total solar irradiance and the open solar magnetic field. Here we show that the open solar magnetic field can be obtained from the cosmogenic radionuclide Be measured in ice cores. Thus, Be allows to reconstruct total solar irradiance much further back than the existing record of the sunspot number which is usually used to reconstruct total solar irradiance. The resulting increase in solar-cycle averaged TSI from the Maunder Minimum to the present amounts to (0.9± 0.4)Wm. In combination with climate models, our reconstruction offers the possibility to test the claimed links between climate and TSI forcing.