Together with Jean-Louis Le Mouël and some Russian colleagues, we have shown that some specific features of the magnetic field were remarkably well correlated with some variations in the sun’s activity – which in itself was not surprising – but the fact that it also correlated with the mean global temperature of the lower atmosphere came to us as a real surprise. This is how I started to get interested in climatology at the decadal to centennial time scale, an area which is not my specialty, though I had already encountered climatologists at the million year time scale with the Indian volcanism.