Tuesday, May 26, 2009

Good news for coral reefs

I suppose this very good news will come as something of a surprise to many people. The mystery being why.
Simple common sense and a passing knowledge of the recent climate history of the Earth would mean that these research findings would have been completely expected.
It's simple really. The organisms that build coral reefs today have been around for a long time. In just the last 10,000 years (a very short period of time geologically) they have lived through the Holocene Climate Optimum (much warmer than today and quite long lasting), a cool period, a possible warm period in "Minoan" times (around 1500 BC), another cool period, the Roman Climate Optimum (around 2,000 years ago and warmer than today), yet another cool period, the Medieval Warm Period (around 1,000 years ago and warmer than today) and then the most severe cold spell of the last 10,000 years, so cold it is known as the Little Ice Age, which only "ended" in 1850 (though the overall warming trend had set in at least a couple of hundred years earlier).
This graph roughly corresponds to the above (the results of proxy temperature reconstructions are never going to be totally in agreement):
And they have survived. Of course they've got survival strategies that we are only just starting to become aware of (see below). Just as do polar bears and emperor penguins.

Andrew Bolt

Monday, May 25, 2009 at 12:04am

How often has Professor Ove Hoegh-Guldberg warned us that the Great Barrier Reef is about to die any second now from man-made warming? Example:
And how often have his predictions proved wrong?
That hasn’t stopped him from being showered by millions and hailed by the ABC as a noble prophet. It hasn’t stopped his latest scare from being laughed out of court. But now, bit by bit, the evidence against his alarmist is building, even in the New Scientist:
In oceans around the world, heat-resistant algae are offering the prospect of a colourful future for corals. The reef-forming animals are upgrading their symbiotic algae so that they can survive the bleaching that occurs in waters warming under climate change.
“The most exciting thing was discovering live, healthy corals on reefs already as hot as the ocean is likely to get 100 years from now,” says Stephen Palumbi of Stanford University…
What’s more, during a heatwave on the Great Barrier Reef in 2006, an Australian team found that many corals that survived the hot period had swapped their algae for more heat-resistant ones… The heat-tolerant algae allow corals to survive 1.5 °C rises in temperature above their usual range. In some regions, this may be enough to survive through to the end of the century despite global warming. Palumbi says that other experiments in American Samoa suggest corals may have more tricks to survive in warmer seas.

Posted via email from Garth's posterous

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