Increased atmospheric concentrations of greenhouse gases produced by human activities
have led to a global rise in surface temperature. Since the beginning of the 20th century
average surface temperature increased by about 0.8ºC (1.4ºF). Climate model projections indicate that the global surface temperature is likely to increase by another 1.1 to 6.4ºC (2 to 11.5ºF) until the year 2100 depending on man-made greenhouse gas emissions during that time. The consequences of the warming may be severe. The combination of the thermal expansion of warming waters and the increased melting of glaciers and ice-sheets will lead to a rise in sea-level. The projections are in the range of 56-200 cm (22-79 in) for the 21st century. Potential consequences for shore-based cities and communities run the gamut from coastal erosion and more catastrophic storm surges to a total loss of low-lying areas or islands. Global Warming is also causing a shift in weather patterns. Some regions have experienced an increase in heavy rain events whereas other regions are subject to longer or more severe droughts. Overall, the consequences of Global Warming are a threat to the livelihood of millions of people.
