Top of the list is a solar shade, a gigantic umbrella in space that would shield the Earth from the sun's rays.

ECONOMIST: Geo-engineering

The Sun's magnetic field and solar wind - mainly in the form of electrons and protons coming out of the Sun - protects the entire Solar System by acting as a sort of shield from cosmic rays (very energetic particles and radiation from outer space).

BBC: Viewpoint: The Sun and climate change