PLEA Network

5 June 2016, The Conversation, A hard rain’s gonna fall: deep water for the election campaign. With an unprecedented storm flooding large population centres on Australia’s east coast over the weekend, you would be forgiven for thinking politicians on the campaign trail might pause to reflect on climate change. On the other side of the world, France and much of west and northern Europe are also experiencing extensive floods. They are unprecedented in the speed at which they have deluged cities and communities. Climate change did not over determine these floods in Australia and Europe. But, it has super-charged their intensity and speed in a way that would make them rare in the past. The weather patterns are complex, but the climate change part of the science is less so. Every 1℃ increase in global average temperature means the atmosphere can hold 7% more water vapour. This means that when moist air condenses into rainfall, it is capable of coming down for much longer and in much greater volume than it did in pre-industrial times. Climate change is not about some kind of linear increase in temperature. It is about an increase in energy in the climate system that produces extremes – in drought, storms, wind, heatwaves and floods. Floods are just one of the expressions of the violence of the excess energy. Analysis from the Potsdam Institute for Climate Impact Research, published last year and reported in the New York Times, showed record-breaking rainfall has increased 12% from 1980 to 2010 compared to the previous 80 years. In Europe, the increase was 31%. This is because the northern hemisphere temperature anomalies are so much greater than the south.Read More here