Saturday, January 21, 2012

Hope spins eternal

It's well past time to start the New Years posts...
The Australian had to mine through several issues of Nature Climate Change to find a "feel good" climate change story.

Coral breakthrough offers climate hope

CORAL reefs may be much better able to adapt to rising sea temperatures due to climate change than previously thought, according to a breakthrough Australian discovery revealed yesterday.
According to PhD student Emily Howells, the findings demonstrate the potential for corals to adapt is more widespread than previously thought.

Further research is under way to establish the speed at which coral can adapt to rising water temperatures, and whether it will be fast enough to survive the impact of climate change.
However, a few paragraphs into the story...
"The algae we are working on occurs up and down the Great Barrier Reef and we are finding that even though it is the same type of algae, those in warm locations have adapted to warm water temperatures and those that are in cooler places, over many years, have adapted to cooler temperatures," Ms Howells said.

"We really don't know about their rate of adaptation to temperature change."

The title of the paper in the December issue of Nature Climate Change is far less dramatic.
Coral thermal tolerance shaped by local adaptation of photosymbionts
(Published online 18 December 2011)
Here we demonstrate divergent thermal tolerance in a generalist Symbiodinium type from two different thermal environments.
Juvenile corals associated with Symbiodinium from the warmer reef grew rapidly when exposed to 32 °C, yet underwent bleaching and tissue death when associated with Symbiodinium from the cooler reef. These results demonstrate that Symbiodinium types can adapt to local differences in thermal climate and that this adaptation shapes the fitness of coral hosts. If Symbiodinium populations are able to further adapt to increases in temperature at the pace at which ocean climates warm, they may assist corals to increase their thermal tolerance and persist into the future.
Emphasis mine.

It's great that this fundamental biophysical research demonstrates that a generalist Symbiodinium has developed tolerance to raised water temperatures, and that it might therefore be possible for coldwater corals to adapt to these conditions. But the abstract has the usual cautious caveats: might, if, could, may.

Will they also be able to do so under the combined stress of acidification?

Of course even a cursory look at the tables of contents from the surrounding issues shows that this "breakthrough" is just one very small glimmer of "hope" in the, most probably, damaging changes projected for the future.

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