Dr Harrison is an expert on climate change over the past 10,000-20,000 years and describes why the world is likely to see between a rise of between 2 degrees and 4 degrees centrigrade in mean global temperature by 2100 and a rise of 1m - 2m rise in sea level, due to thermal expansion, which could have extremely serious consequences for the Isles of Scilly and other islands all over the world.