Climate models predict that warming in polar regions will be larger than the global average. These regions therefore have been the focus of attention in searches for measurable evidence of climate change. Quayle et al (2002) report data from Antarctic lakes that indicate rapid ecosystem change in recent years. Measurements of air temperature from 1950 to 1990 show a 1ºC rise in 40 years (compared to a global average of about 0.5ºC rise in 100 years). Lake water temperature, number of mean annual ice free days, and chlorophyll concentrations all show marked increases over the last 16 years. Ecosystem studies confirm that these rapid changes in climate also are causing extreme ecosystem changes.
Reference
Quayle, W. C., L.S. Peck, H. Peat, J. C. Ellis-Evans, and P R. Harrigan, 2002: Extreme responses to climate change in Antarctic lakes. Science, 295, 645.