Over the 21st century, the temperature of the earth's surface is likely to increase by several degrees and all ecosystems, including forests, will experience the most rapid period of climate change for over 10,000 years, since the end of the last ice age. The distribution and composition of forests will almost certainly be affected, and it is vital that effective conservation strategies accommodate the prospect of rapidly migrating and shifting ecosystems. However, planning for climate change is made difficult by the fact that our understanding of the subtle interactions between the biosphere and atmosphere is still in its infancy. Uncertainties emerge both in the specific predictions of climate change scenarios; these uncertainties are greater when considering specific regional changes than when considering global changes. These considerations have determined the structure of this report: we start by considering predictions for global climate change and the general scientific principles underlying the interaction between vegetation and climate, before moving on to examine likely scenarios for each forest region.