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Entries in GCC (9)


Who you calling a crackpot scientist?

There’s an interesting article in the South African news media about a UN moratorium on the sort of geo-engineering ideas described in my recent discussion with Pete Strutton.  The general gist of the moratorium is that the UN is saying “lets not do any more of this sort of research until we have a better idea whether its going to work and at what cost”; its not an ethical prohibition in the sense of the human cloning sort of ban.  Consequently, the South African piece describing proposers of geo-engineering as “crackpot scientists” is absurdly harsh and sensationalist journalism at its worst.  I can say with confidence that scientists studying geo-engineering concepts are simply trying to propose solutions to what will certainly be the most vexing global challenge of our generation.  As stated in this Scientific American piece:

Major scientific organizations — including the American Meteorological Society, the American Geophysical Union and the U.K. Royal Society — have issued cautious calls for more research, though warning that geoengineering approaches shouldn’t supplant efforts to cut greenhouse gas emissions.”

In my ideal world, it would be a social norm that you can’t object to an idea unless you propose a justifiably better alternative.  Certainly there are questions to be answered about who gets to make the call on these global-level solutions (even mentioned here back in March).  But as it stands, with Kyoto and Copenhagen essentially failing to effectively retard the source of the issue (greenhouse gas emissions), we can ill-afford the UN to be hindering research into possible solutions, without offering something better.


Tilting the three-way tango - disease as a loss of diversity

ResearchBlogging.orgDisease is a funny old thing.  We're taught from very early on that disease agents are "bad" and that, by contrast, the infected are somehow poor and unfortunate victims of nasty evil bugs.  This is clearly a cultural bias, wherein we project our own concerns about getting sick onto all other animals; there's no real reason to think that a bacterium or virus has any less right to be here or any less important role in the ecological processes of the world than does the dolphin it infects, or the fish or the lobster.  We have all survived eons while avoiding extinction, which makes us winners in the great game of evolution, the microbes every bit as much (or more) than their hosts.

Still, biases run deep.  This is important because sometimes they cloud our perceptions of whats really going on.  Consider coral diseases for a moment.  What, you didn't know that coals get diseases?  That's OK, neither did most folks, including many scientists, until fairly recently.  Lets picture a nice reef coral, maybe a handsome Porites, infected with one of the many "band"-causing agents (diseases that march across the surface of the coral, destroying tissue along a coloured front that gives the disease its name).  Most folks would perceive that the coral (good) was quietly minding its own business when it was "infected" by the microbe (bad), causing disease.  But actually it took at least three players to tango in this case; the coral had to be susceptible to the pathogen, the pathogen had to be infectious to the coral, and the environment had to set the scene that made the interaction swing in favour of the pathogen.  This simple "disease triad" is the most basic model of how infectious processes take place, but its just that: a basic model.

These days, disease studies are becoming a lot more nuanced, and its revealing a whole new world of how diseases start and stop.  Rocco Cipriano, a microbiologist colleague of mine at the National Fish Health Labs in Leetown WV, has been promoting a model lately where an infectious disease of fish (furunculosis) is caused by a disruption to the natural community of bacteria on the skin of fish; a community in which pathogens have no place normally.  The furunculosis agent (Aeromonas) is excluded from these communities by bacteria better adapted to living in normal fish skin and its associated mucus layer.  That is, until an environmental modulator, like a temperature spike or pollutant, shakes things up a bit; what ecologists would call disturbance.  And what is the first outcome of disturbance in most systems? Loss of diversity, in this case among the normal bacterial community.  Some bacteria disappear from the skin of the fish, freeing up resources (space, food) that are exploited by other bacteria - opportunists that can come in and pounce on the new space or food.  When that space and food consists of the fish itself, we call those bacteria pathogens.  This same process happens after any ecological disturbance, like a hurricane on a reef or a tree falling in a rainforest: opportunists come in and pounce on a newly-available resource; then as things settle down a succession takes place, until the early colonisers are displaced by more typical fauna.  In this view, disease is nothing more than a byproduct of disturbance and loss of diversity in the normal microbial community.

Which brings me back to corals and to the recent paper by Mao-Jones and colleagues in PLoS Biology.  These folks used a mathematical model to show that much the same holds true for the diseases of corals, which, like fish, rely heavily on a surface layer of mucus as their first line of defence.  It seems that in both corals and fish, the mucus is important, but even more important are the normal bacteria that live there, continually excluding pathogens and acting as a protective guard against disease.  In a very anthropomorphic sense, the corals (and fish) are using the surface bacteria as a biological weapon against the potential pathogens, at the expense of having to produce all that mucus for the bacteria to live and feed on.  Importantly, Mao-Jones and friends show us that the derangement of the mucus community can persist for a really long time after the initial disturbance.  This is important, because you often come along and see disease starting, but you may well have missed the initial insult that got the ball rolling, which may have occurred some time ago.

I really like this idea of infectious disease as an ecological disturbance and of many pathogens as simply early colonisers in the succession back towards health (or towards death, if the disturbance was too severe).  As a model, it doesn't work for everything, though.  There are many "primary pathogens" that are specifically adapted to invade healthy animals, but its not in the best interests of those organisms to invest so much energy in adaptations to invasion, only to kill the host, thus many of those are fairly benign.  For more "opportunistic" agents, however, I suspect it holds true much of the time, and that group includes many or most of the really virulent diseases.  I dare say many of the "emerging" diseases fall in this category, and we can expect to see more of this as the global climate continues to tilt the tango in favour of the pathogens.

Mao-Jones, J., Ritchie, K., Jones, L., & Ellner, S. (2010). How Microbial Community Composition Regulates Coral Disease Development PLoS Biology, 8 (3) DOI: 10.1371/journal.pbio.1000345


Me and Terry Hughes, we got Kwan

This is a little spooky. Terry Hughes of the Center for Excellence in Coral Reef Studies in Australia, whom I know only vaguely, has been quoted on the topic of the Shen Neng 1, that Chinese coal ship that ran aground on the Great Barrier Reef. His somewhat dismissive tone sounds creepily like my recent rant on the subject.

He said:
"The [Shen Neng 1] ship grounding, in the scheme of things, is not a major incident. It's bad if you happen to be one of the corals the ship parked itself on, but it's tiny in the face of the real problem: global warming."

I said:
"I am not worried in the slightest about this incident.  Not that its a good thing - far from it - but this accident is nothing more than a tree, obscuring us from seeing one big and scary forest [burning fossil fuels]."

Terry, you're my Ambassador of Kwan.


Q: When is a ship like a tree?

A: When you can't see the forest for it.

You may have followed some press in the last week or so about a Chinese coal ship, Shen Neng 1, that ran aground on the Great Barrier Reef and spilled some of its fuel oil.  This has caused a regular frenzy in the Aussie media and the global conservation and environmental news-o-sphere.  There have been all sorts of calls for prosecution of the shipping company and new stringent regulations for the transport industry and so on, along with dramatic accounts of the damage the ship did and the risky salvage operation that came next.  But you know what?  I am not worried in the slightest about this incident.  Not that its a good thing - far from it - but this accident is nothing more than a tree, obscuring us from seeing one big and scary forest.

The main reasons I am not especially bothered by the Shen Neng accident are that (1) it affected a very limited area - the G.B.R. is really B.I.G. and one ship can only damage so much of it; and (2) it was a single event in time - this was not a process or an ongoing problem, but a singular disturbance.  Science shows us that the GBR, and reefs in general, are amazingly resilient to violent disturbances like this; a decent cyclone can literally turn a reef upside down, and a couple of years later you'd never know the difference.  Indeed, periodic disturbances may  be really important for maintaining a healthy reef ecosystem.

No, the Shen Neng is just a tree, obscuring us from seeing the forest that really threatens the future of the GBR and all reefs.  Its not the 2km gash that the hull cut in the reef, nor is it the tons of fuel oil leaked into the water; it's the very concept of burning that fuel oil, and burning the thousands of tons of coal that the Shen Neng 1 was carrying.  When you consider all the other ships and all the coal and fuel they were carrying that day and every day, and all the cars in the world, the power plants and so on ... ach, you get my point.  THAT'S what we ought to be worried about, because both of the main effects of increased atmospheric CO2 - warming and ocean acidification - will likely result in unrecoverable damage to All reefs. Everywhere. In our lifetime.  Warming is directly linked to lethal bleaching events, while acidification disrupts the ability of reefs to lay down their skeleton and grow.   Oh yeah, and lets not forget the drowning effects of sea level rise, too.  The more I think about it, the more it seems that jumping up and down about the Shen Neng is hypocritical (coal is one of Australia's biggest exports, after all) and akin to complaining about the deck chair arrangements of another, even bigger, ill-fated ship.  (Ironically, if Titanic sailed today, she probably wouldn't have to worry about icebergs...)

Of course, its a false dichotomy, we should be worried about BOTH the Shen Nengs of the world AND the global climate change/ocean acidification.  But I only have so much energy/capacity for worrying about these things, so with a limited anxiety budget, I feel compelled to focus on the bigger issue and what (if anything) we can do about it - to try to reduce consumption and to try to make sensible decisions that are mindful of how much energy is involved and what the broader impacts might be.

In other words, to worry about the forests - and let the trees take care of themselves.


More on the geo-hacking idea

Not so long ago I posted about the idea of capturing all the extra atmospheric CO2 into the worlds oceans by fertilising them and thereby creating enormous plantkon blooms that would convert all the CO2 to plant tissues, which would then sink to the bottom and be buried in the ocean depths.  This new scientist article probes a different angle that I didn't think of, which is Who decides what we will or won't do to change these things?  The author Jim Giles refers not just to ocean fertilising, but engineering the whole planet to combat climate change - what has become popularly known as "geo-hacking" - including sensible concepts like reforestation and cloud seeding, as well as the more absurd notions such as building giant reflectors to bounce the sunlight away.  Its a thought provoking question, so who do you think should decide these issues?  The US? UN? UNESCO?  Perhaps we need a new body with that as its sole charter?


If you can catch lightning in a jar, why not gas in a puddle?

Imagine if you could take all the greenhouse gases and somehow keep them away from the atmosphere, where they would otherwise contribute to global climate change.  Well that's kind of the idea behind SOFEX, a huge experiment done by marine scientists a few years back (my buddy and fellow Aussie Pete Strutton was involved).  The idea stemmed from an observation that the growth of plankton (which absorb carbon dioxide as they grow and multiply) in the oceans is limited by some nutrients, especially iron.  So, if we fertilise the oceans with iron, perhaps we can get the plankton to "bloom", suck up all the carbon and then sink to the bottom, taking the greenhouse gases with them.  The colour picture hereabouts shows a satellite view of an artificial bloom created by adding iron to the ocean.  It was actually a neat idea, except I could never shake off the feeling that the stuff would resurface one day and that it was just delaying the inevitable; it depends to some degree on whether the sunken material gets buried on the bottom or not, I guess.

Well, the idea recently received another blow; a new paper in PNAS reports that the sort of plankton that bloom after iron fertlisation are the same ones (Pseudonitzschia ) that produce domoic acid, a nasty toxin that causes horrible problems as it accumulates higher up the food chain, especially in sea lions and other marine mammals.

Marine mammals are kind of a sacred cow in biology, so my guess is that that will be that for iron fertilisation.  Ironically enough, the whole problem with domoic acid in the oceans, which is a relatively new phenomenon, may have climate change as its root cause anyway - blooms of Pseudonitzschia are supposed to have increased in frequency and intensity because of environmental changes.  You can't win, sometimes.


Lazy SCUBA divers - pushing back the frontiers of climate science since 1970

Confused?  Read on...
Australia's CSIRO (the primary government-funded scientific research body; the kool kids say it like SIGH-row) has taken possession of a SCUBA tank last filled by its owner, a Mr. J. Allport, in 1968.  This may represent among the oldest clean compressed air currently available, and the boffins at CSIRO (one such boffin shown below), hope to use the contents to extend the directly-measured CO2 record back a few more years.  This would help improve the quality of climate data just a teensy bit more.  Admit it, that's kinda awesome.

I should call them. I'm pretty sure I've got a ham sandwich from 1982 somewhere in the attic; that must be useful for something...


Giant iceberg threatens Australia

Sounds odd right?  I mean, the sunburnt country - itself "adrift" in the southern oceans - on a collision course with a giant chunk of ice?  And yet, thats exactly the scenario unfolding off SW Western Australia.  Supposedly it broke off the Ross ice shelf, one of the largest on the planet.

The people in Perth could make a lot of gin and tonics...



Some time ago I noticed there wasn't as much going on in the blogosphere with respect to marine science as I would like, but I was really prompted to start writing by the press release last week from IUCN naming the 10 species - other than polar bears - most likely to suffer as a result of climate change.  Seven of those were aquatic and we had all of them, or close relatives, in the collection at Georgia Aquarium.  In choosing these particular species, the IUCN underscored the significant role of the oceans in global climate change processes.  This is tremendously important because I think most folks still regard GCC as a terrstrial issue.  Its not: evidence is growing that the ocean is the single largest driver of climate, and the response of the oceans to increasing greenhouse gases will determine how GCC plays out, including which models - if any - most closely meet the changes we observe.  The oceans are our best friend in this respect, absorbing excess carbon dioxide and dampening the effect of all that fossil fuel burning, but they do it at the expense of their inhabitants and they can only do it up to a point.   I expect this will be a topic we return to pretty regularly; it should be higher on many people's climate change radar, and we can hope that it features prominently in discussions in Copenhagen this week.

When I thought a little more about it, it shouldn't be at all surprising that ICUN picked 70% aquatic species for their list; after all, 70% of the earth is covered in water...