Evidence of Climate Change

In February 2007, the IPCC (Intergovernmental Panel on Climate Change) issued its latest assessment report on climate change, which concluded that global warming is "unequivocal" and gave the strongest warning yet that it is very likely (> 90%) caused by human activities

The evidence for global warming and climate change includes the following:-
Sea temperatures have risen by on average 0.5 degrees C (0.9 degree F) over the last 40 years [Tim Barnett, Scripps Institution of Oceanography in La Jolla, California]
20,000 square kilometers of fresh water ice melted in the Arctic between 1965 and 1995 [Ruth Curry, Woods Hole Oceanographic Institution in Connecticut]
Worldwide measurements from tidal gauges indicate that global mean sea level has risen between 10 and 25 cm (18 cm average) during the last 100 years [Warrick et al., 1996]
Global surface temperatures have risen about 0.7°C in the past 100 years [Met Office]
11 of the last 12 years rank amongst the 12 warmest years on record for global temperatures (since 1850) [IPCC, 2007]
Since 1975, the increase of the 5-year mean temperature is about 0.5°C - a rate that is faster than for any previous period of equal length [NASA, 1999]
Average annual temperature in the Arctic has increased by about 1° C over the last century -- a rate that is approximately double that of global average temperatures [IPCC, 1998]

There is widespread evidence that glaciers are retreating in many mountain areas of the world. For example, since 1850 the glaciers of the European Alps have lost about 30 to 40% of their surface area and about half of their volume [Haeberli and Beniston, 1998]