Dr David Etheridge, CSIRO Atmospheric Research Scientist was guest speaker at the BCCAG AGM on Wednesday 29 July. David has led 5 scientific expeditions to Antarctica investigating ice sheets changes, atmospheric turbidity and atmospheric composition in ice cores.
David spoke about his Antarctic ice cap research. Changes over hundreds of thousands of years can be compared to recent changes by studying air trapped in bubbles in ice cores. This shows that current levels of GHG and ozone depleting CFC’s have not been seen for 2 million years. The main contribution to climate change are GHGs generated from burning fossil fuels. Solar variations and volcanic eruptions make a very small contribution. The world contributes 1000 tonnes/sec of CO2e to the atmosphere from burning fossil fuels.
Antarctic ice sheets are becoming increasingly vulnerable to melting. A third of the 3mm per year sea level rise is due to melting of two polar ice sheets (in Antarctica and Greenland).