Professor Martin Parry of the UK's Meteorological Office estimates that a rise of just 2.1 degrees will expose between 2.3 and 3 billion people to the risk of water shortages. The disappearance of glaciers in the Andes and the Himalayas will imperil the people who depend on their meltwater, particularly in Pakistan, western China, Central Asia, Peru, Ecuador and Bolivia. As rainfall decresases, there are likely to be longer and more frequent droughts in southern Africa, Australia and other countries surrounding the Mediterranean.