In 2005, Flannery predicted Sydney's dams could be dry in as little as two years because global warming was drying up the rains, leaving the city "facing extreme difficulties with water".
Check Sydney's dam levels today: 73 per cent. Hmm. Not a good start.
In 2008, Flannery said: "The water problem is so severe for Adelaide that it may run out of water by early 2009."
Check Adelaide's water storage levels today: 77 per cent.
In 2007, Flannery predicted cities such as Brisbane would never again have dam-filling rains, as global warming had caused "a 20 per cent decrease in rainfall in some areas" and made the soil too hot, "so even the rain that falls isn't actually going to fill our dams and river systems ... ".
Check the Murray-Darling system today: in flood. Check Brisbane's dam levels: 100 per cent full.
All this may seem funny, but some politicians, voters and investors have taken this kind of warming alarmism very seriously and made expensive decisions in the belief it was sound.
So let's check on them, too.
In 2007, Flannery predicted global warming would so dry our continent that desalination plants were needed to save three of our biggest cities from disaster.
As he put it: "Over the past 50 years, southern Australia has lost about 20 per cent of its rainfall, and one cause is almost certainly global warming ...
"In Adelaide, Sydney and Brisbane, water supplies are so low they need desalinated water urgently, possibly in as little as 18 months."