The BBC has a good roundup of the top 10 climate change denier arguments with rebuttals from scientists who agree with the Intergovernmental Panel on Climate Change: that it’s happening, it’s due to us, and the potential damage is serious.
Worthwhile reading for those who still find themselves in these kinds of arguments in the home, the office or at the pub over a cup of cocoa. Arm yourself.
3. The earth has been warmer in the recent past
The beginning of the last Millennium saw a “Mediaeval Warm Period” when temperatures, certainly in Europe, were higher than they are now. Grapes grew in northern England. Ice-bound mountain passes opened in the Alps. The Arctic was warmer in the 1930s than it is today.
There have been many periods in Earth history that were warmer than today – if not the MWP, then maybe the last interglacial (125,000 years ago) or the Pliocene (three million years ago). Whether those variations were caused by solar forcing, the Earth’s orbital wobbles or continental configurations, none of those causes apply today. Evidence for a Mediaeval Warm Period outside Europe is patchy at best, and is often not contemporary with the warmth in Europe. As the US National Oceanographic and Atmospheric Administration (Noaa) puts it: “The idea of a global or hemispheric Mediaeval Warm Period that was warmer than today has turned out to be incorrect”. Additionally, although the Arctic was warmer in the 1930s than in the following few decades, it is now warmer still.