After a long and distinguished career in that field, Professor Alexander is well placed to evaluate the effects of climate change on water supply against claims that man-made warming will lead to catastrophic consequences for our ability to sustain life. His chief findings are: Neither African floods nor droughts have increased in the period that climate change is alleged to have happened; Prof. Alexander's research team has found wet and dry years correlate much better to movements in the solar system and activity on the sun itself rather than and man-made climate change hypothesis.