The Great Barrier Reef and the prophets of doom

The alarmists have gone too far out on a very long limb for any retreat. A cooling trend in climate would be disastrous for the whole anthropogenic global warming ideology and result in a catastrophic loss of credibility for a large sector of the scientific community. The escalating fears they express appear to be based not so much on any important new evidence as on their own increasingly desperate hopes.

As for coral bleaching, the central fact never mentioned is that the high surface water temperatures associated with bleaching events are not the result of exceptionally high air temperatures. They result from extended periods of calm weather during which mixing from wave action ceases and surface layer becomes exceptionally warm. Such warming is especially marked in very shallow water such as on reef flats. At the same time the absence of waves also eliminates the wave driven currents that normally flush the reef top.

Bleaching conditions require at least a week or more of calm weather to develop and this may happen every few years, only once in a century, or never, depending on geographic location. On oceanic reefs it is less common due to ocean swell and currents even in calm weather. In coastal areas it is more common due to the absence of swell and reduced currents.

There is nothing to link extended periods of calm winds with global warming. In fact the climate models project increased winds.

Incidentally, I am a great admirer of Charlie Veron's outstanding work on coral systematics and have high regard for his knowledge of reefs but feel compelled to respectfully disagree with his pronouncements on climate change.