Having explored the role of climate change in our past and its implications for our evolution, it seems appropriate to ask how this analysis affects thinking on current climate change. Any attempt to consider the climatic challenges of the future must draw on some prediction of what the climate will do in, say, the next century. Given the range of choices available, this does permit considerable freedom in selecting whatever model most effectively matches the line taken in this book. To deflect any accusation of bias, the best thing to do is to use the conclusions reached in the most recent report from the Intergovernmental Panel on Climate Change (the IPCC Third Assessment Report (TAR), published in 2001; see Bibliography). This contains the most complete statement of what the majority of the meteorological community considers the climate will do in the twenty-first century. Behind this façade there is, however, a wide range of uncertainties in many of the physical arguments, and hence in how global warming will affect different parts of the world. This allows plenty of choice in exploring how the impact of past climate change on human history can inform us about the challenges that lie ahead.