We're joined by Professor Achim Brauer from the German Research Center for Geosciences in Potsdam to discuss the topic of climate change. He is an expert on the influence of solar activity that's happened in the past - specifically 2800 years ago is what his study is focussing on. For more go to http://www.dw.de/tomorrow-today-the-science-magazine-2012-12-03/e-16374982-9798