  It has been proposed that galactic cosmic rays may influence the Earth's
climate by affecting cloud formation. If changes in cloudiness play a part in
climate change, their effect changes sign in Antarctica. Satellite data from
the Earth Radiation Budget Experiment (ERBE) are here used to calculate the
changes in surface temperatures at all latitudes, due to small percentage
changes in cloudiness. The results match the observed contrasts in temperature
changes, globally and in Antarctica. Evidently clouds do not just respond
passively to climate changes but take an active part in the forcing, in
accordance with changes in the solar magnetic field that vary the cosmic-ray
flux.
