Antinuclear

The heatwave projections, released on Friday during what was expected to be Sydney’s hottest three-day spell in November in almost eight decades, cover the period to 2030 and then out to 2070.

The shift towards hotter weather is already evident, with south-eastern NSW experiencing about 18 more heatwave days a year compared with the start of the 20th century, the Office of Environment and Heritage says.

For most other parts of the state, the increase was about four-11 days.

The research, based on 12 climate models as part of the NSW and ACT Climate Modelling Project (NARCliM), estimates that most of the state will experience 1-1½ more heatwave events a year by 2030.

The number of heatwave days – defined to be excessive heat compared with historical records and the preceding 30 days – will increase by as much as 10 days a year by 2030 in the state’s north, with smaller increases near the coast. (See chart below showing the rising percentage of heatwave days each year.)

This provides a clear indication that, out to 2030, we can expect the heatwaves to happen more often, and for them to be longer,” Matthew Riley, director of OEH’s Climate and Atmospheric Science, said.

“[The models show] even more heatwaves out to 2070, that last longer still, and are becoming hotter,” Mr Riley said……http://www.smh.com.au/environment/climate-change/think-this-is-hot-warming-climate-points-to-heatwaves-worsening-in-nsw-20151120-gl3nwt.html