I spent the last couple of days in Canberra at the Coral Reef Futures Forum, as part of my new Federation Fellowship is to look at economic approaches to management of the Great Barrier Reef. As one of the speakers said, a lot of the talks had people staring at their shoes in gloom, though the tone got a little more positive towards the end. I’m an optimist on ecological issues which is fortunate, because when you look at the threats facing coral reefs, you need a lot of optimism. Looking at historical data, even the GBR, which is much better managed than most reef systems is significantly degraded relative to 100 years ago, and a large proportion of reefs are at or near the point of no return, thanks to overfishing, destructive fishing methods and marine pollution. When you add regular bleaching due to climate change, and also acidification due to higher CO2 levels, the chances of saving much of the world’s coral reef systems do not look too good.
The most hopeful view is that, if we can fix the local threats like overfishing and poor water quality, the resulting increase in resilience (part of my project is to develop a more rigorous understanding of this popular buzzword) will offset moderate global warming, so that if we can stabilise the climate (an increase of no more than 2 degrees) we might save at least some reef systems.
A few observations:
First, it’s noteworthy how opinion has solidified on the point that bleaching (corals expelling their associated symbiotic zooxanthellae ) is a response to higher temperature driven by general warming of the seas, rather than being due to locally specific causes. Al Gore’s claim to this effect, listed as an error in the recent court case that has been exciting the delusionists, has the full support of everyone I talked to there. Given the regular claim that any scientist who accepts the evidence on global warming must have been bought off by the prospect of grant money, let me observe that the problems we already had with coral reefs are enough to keep every marine biologist on the planet gainfully employed for life without inventing new ones.
Sticking with the delusionists, it’s striking that the McIntyre fan club has been digging up the sorriest dead horse in the annals of delusionism, the urban heat island effect, and has more generally been getting excited about land surface records. Of course, no one at this meeting paid any attention to land surface measurements. The sea temperature records are not influenced at all by UHI and they tell the same story. And of course the satellite data that used to get such a big run is ignored by delusionists now that it confirms the surface records. Unless (as I have while editing Wikipedia for the last few years) you’d seen exactly the same kind of thing play out over the health risks of smoking, evolution, AIDS reappraisal and so on, you would find it hard to believe that anyone could push this nonsense.
While delusionists were thin on the ground, the skepticism that is associated with good science was not. The idea that intact mangrove forests and coral reef systems might provide protection against the destructive effects of tsunamis is appealing, and has been widely promoted, but, it seems, doesn’t stand up to close scrutiny, and the evidence supporting it is an example of spurious correlation. At least that’s what Andrew Baird argued, and he seemed pretty convincing to me. Of course, this will be fought out in the peer-reviewed literature as it should be.
Another rather depressing point to come out was that acidification driven by higher atmospheric CO2 is worse in cold climates, which means that the prospect of reef systems migrating away from the equator in response to climate change is not promising. And of course this is a reminder that radically changing the composition of the atmosphere is going to have a whole lot of effects, which may interact in nasty and unexpected ways.