YOU'D think a record of dud predictions would shame Alarmist of the Year Tim Flannery into silence. But, no.

It seems this professional fearmonger has learned instead that global warming is a faith that grows on panic, not facts.

So, undaunted, Flannery this week amped up the hype to warn that global warming was now so terrifying we may have to change the colour of the sky.

As a "last barrier to climate collapse" we might within the next five years have to fire the "gas" sulphur (actually a solid) into the stratosphere to keep out some of the sky's rays.

(Article continues below)

There are obvious problems with his plan. First, Flannery concedes "the consequences of doing that are unknown". Second, some lousy consequences are known - for a start, sulphur is an element in acid rain.

But third, global warming in fact halted in 1998 - a basic point confirmed by almost all measuring bodies but not yet by Flannery.

How Flannery gets away with such flummery has been a mystery to me, but I blame in part our extraordinary groupthink (see story above). For instance, while 31,000 scientists were happy this week to sign a petition in the United States denying there was convincing evidence that man's gases caused catastrophic global warming, I can't think of more than a dozen in Australia who'd dare do the same.

And I can think of even fewer journalists who'd back them if they did. That's why Flannery is still treated as a hero of the ABC and The Age, despite a string of predictions that should have made him a laughing stock, not 2007 Australian of the Year.

Here's a condensed list.

Three years ago he warned global warming could leave Sydney's dam's dry by 2007. They are two thirds full.

Perth would be so devastated by drought that it would be a "ghost city" in decades. In fact, the city has just recorded its wettest April on record.

The ice caps would melt so fast that the seas would lap the roofs of "an eight-storey building". In fact, the United Nations' influential IPCC, itself accused of alarmism, says at worst the seas will rise this century by 59cm.

Hurricanes would become more frequent. In fact, the long-term trend of hurricanes and cyclones is highly disputed, as is any link to warming.

The hype pushing the global warming scare is the most sustained assault on reason in my lifetime. While Flannery remains a prophet, the rational should tremble, even before he starts firing sulphur into our sky.