Marsden is Here

#SS4CNZ


There was another mass event in Christchurch today, a far more positive one which is in danger of being buried by the bad news. The Secondary School Strike attracted as many people into the square as I have seen in my time of attending such things and there was an underlying energy which is often missing. As if a storm might be building ....

Via SciBlogs, Jim Salinger explains how global warming contributed to the recent Queensland floods.

The causes of these floods have been laid at the feet of the La Niña climate pattern – the sister of El Niño. La Niña brings strengthened moisture-laden easterly winds on to the Australian continent. This year the La Niña event is strong, with it being amongst the top three in magnitude, ranking with the 1918/19 and 1973/74 events. However there is one distinct difference this season: temperatures in Australia this past decade have been 0.5 deg C warmer than in the 1970s, and 0.9 deg C warmer than in the 1910s, all as a result of global warming. And during the 2010/11 season, La Niña seas off eastern Australia have been much warmer than average, being 1 to 2 deg C above the 1985-1998 average.

It is a simple law of physics that a warmer atmosphere holds more moisture. With the long term heating of the oceans more moisture has been measured in the atmosphere during the last decade. The consequence is that global warming leads to an increase in the magnitude and incidence of heavy rainfall, and the resultant floods.