Thursday, 22 January 2009

Antarctica warming: New satellite data

A new study (Steig et al, 22 Jan 2009. Nature 457, 356) has combined long term data from land stations on Antarctica with new satellite data and estimated rates of warming of 0.6 degC over 50 years on Antarctica. Warming is more rapid in the west of the continent. The study concurs with the IPCC assessment that there is at least a 66% probability of warming due to anthropogenic activity. The potential impact of Antarctic warming on sea level and global warming is hard to predict. Scientists are also concerned about the apparently imminent break-away of the Wilkins ice shelf (15,000km2) from the main continent. The image (from Steig et al 2009) shows the temperature anomaly (compared with the mean for the period) for west Antarctica. The black line represents reconstructed temperature based on satellite data, the red line shows the general trend, and the shaded area shows statistical confidence limits.