TOSCA (Towards a more complete assessment of the impact of solar variability on the Earth’s climate).


TOSCA (Towards a more comprehensive assessment of the impact of solar variability on the Earth’s climate) is a multidisciplinary network that brought together over a hundred scientists from 23 European countries between 2011 and 2015. TOSCA objective was to clarify the controversial role of solar variability in recent climate change. This Action was coordinated by the LPC2E.

As for all COST (Cooperation in Science and Technology) Actions, TOSCA aimed at fostering networking between different communities. The Action brought together researchers working on the physics and chemistry of the atmosphere, solar physics, cloud formation, cosmic radiation, statistical methods, and so on. For four years, we focused on issues that require competences from several disciplines; 17 workshops were organized.

TOSCA has improved our understanding of Sun-climate relationships, highlighting the role of poorly known mechanisms, such as the role of atmospheric electricity. To date, none of these mechanisms can explain the current global warming, of which humans are the main culprit.

The outcomes are partly summarised in a book: J. Lilensten, T. Dudok of Wit and K. Matthes (Eds.), Earth’s climate response to a changing Sun, EDP Sciences, Paris (2015).

TOSCA website:


Contact at LPC2E: Thierry Dudok de Wit (