These forecasts should leave us in little doubt about the potential impact of climatic change on the natural environment and humans Changes in climate have the potential to affect the geographical locations of ecological systems such as forests and grasslands the mix of species they contain and their ability to provide the various benefits on which societies depend for their continued existence Thus the whole range of resources on which we rely is sensitive to changes in climate This includes food production water resources and human settlements The effects some of which are potentially irreversible are likely to be unfavourable in many areas