Tim Flannery in his book The Weather Makers has a chapter on three biggies, three possible adverse events in the future of our climate that we should avoid at all costs and that would spell big trouble for the climate system as a whole – and for us.
My copy of his book is still sadly packed in a box under the house, but I think one was the melting of ice sheets. I’m almost certain the second was the interruption of the Gulf Stream but I’m very sure the third was the possibility of the Amazon rainforest drying out and collapsing as an ecological system.
Last month The Independent carried a story Amazon rainforest ‘could become a desert’ – “And that could speed up global warming with ‘incalculable consequences’, says alarming new researchâ€?.
Via that link you will find the full article, if you are not a subscriber, with value added by way of emphasis and some interesting comment.
The vast Amazon rainforest is on the brink of being turned into desert, with catastrophic consequences for the world’s climate, alarming research suggests. And the process, which would be irreversible, could begin as early as next year.
Studies by the blue-chip Woods Hole Research Centre, carried out in Amazonia, have concluded that the forest cannot withstand more than two consecutive years of drought without breaking down.
You might like to compare the
As the forest becomes shorter and its canopy more open, compromising its remarkable resistance to fire, it is clear that drought in tandem with fire could swiftly push the tall, dense rainforests of the region towards savanna scrub. The amount of carbon that could be released to the atmosphere by this savannization process is significant—equivalent to several years of worldwide carbon emissions —and could accelerate climate change processes already in place.
In addition to these global effects, drought and fire, a tool of choice among the Amazon’s farmers and ranchers, pose a serious threat to a forest that is home to more plant and animal species, and more indigenous cultures, than any other forest in the world.
The research has shown that while the younger trees and the understory were surprisingly resilient the large canopy trees started to die with three years of drought, opening the forest floor to drying and making it more susceptible to fires. Fire is already a feature of the Amazon and indeed last September satellite technology identified 73,000 separate fires in the Amazon basin.
The reasons for the drought seem to be twofold. First the ocean in the Caribbean and the northern tropical Atlantic is warming, leading to changes in the normal general circulation patterns resulting in increased hurricane activity. This interrupts the warm trade winds that bring rain to the Amazon.
Secondly, conditions in the Amazon are such that you don’t get the same updraft of moist warm air which would pull in the air from the Atlantic. This article suggests:
So far about a fifth of the Amazonian rainforest has been razed completely. Another 22 per cent has been harmed by logging, allowing the sun to penetrate to the forest floor drying it out. And if you add these two figures together, the total is growing perilously close to 50 per cent, which computer models predict as the “tipping point” that marks the death of the Amazon.
Tim Flannery points out that half the rain that falls in the Amazon basin is from what has been called evapotranspiration. He further points out that with increased CO2 concentrations in the atmosphere the stomata don’t stay open as long thus limiting plant transpiration of moisture. Transpiration is also lessened under drought stress as the plant goes into dormant mode.
If all this seem straightforward go and read what the real climate scientists say at RealClimate. For me, a non-scientist, it all becomes very complicated and I have the distinct impression that the science is far from settled.
The reality is, though, that we’ve had one year of drought, things are not looking good this year and if the problem persists into a third year there may be no return.
What this would mean for world climate is not entirely clear to me, but it looks serious. Mention was made of 90 billion tons of carbon stored in the Amazon rainforest. It sounds a lot. The only comparator (if that’s a word) I can find is the 34.4 gigatons of CO2 equivalent ABARE gives (large pdf) for greenhouse gases emitted in 2001. I still don’t know how those figures strictly compare, but let’s say the amount of stored carbon in the Amazon is massive and to have it switch from a carbon store to an atmospheric greenhouse booster is likely to, as they say, have consequences.
And there is nothing I can see that we can do except wait and watch to see whether this saga is about to unfold. Meanwhile as one commenter said “the bickering-with-bombs in the Middle East will continue�, the sun will come up tomorrow and we will go about our business as normal. It’s kinda depressing!
Forget the bickering with bombs in the ME, there’s a real stoush on with Downer taking up the cudgel for the little guy blogger against the big bad NGO http://www.news.com.au/story/0,10117,20298594-401,00.html?from=public_rss
Now aint that something to gladden the heart of any leftie?
“Tim Flannery points out that half the rain that falls in the Amazon basin is from what has been called evapotranspiration. He further points out that with increased CO2 concentrations in the atmosphere the stomata don’t stay open as long thus limiting plant transpiration of moisture.”
But thats precisely what could help SAVE the rainforest. The plants need less water when they have more CO2 since extra CO2 reduces transpiration.
The important point here is that ONLY HALF of the water comes from that. Half comes from elsewhere. The reduced plant transpiration is not hurting the amazon since its only taking away from it the water that the plants themselves no longer perspire.
You see how the MOMENTUM takes over? Folks should be seeing this by now.
Here is the Amazon being destroyed NO by fire and bulldozer….. And we are getting distracted from the unlikely idea that it MIGHT sometime in the distant future be destroyed by CO2.
But it will be burnt and bulldozed all to hell by then……
We ought to be ambitious enough to want to recover it. And restore it. And the CO2 will help with the recovery.
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As discussed before. We have no relevant precedent for the Gulf War switching off. Its not plausible that it would switch off as a result of more CO2.
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The melting ice sheets are a good thing. Because it means we’ve bought ourselves a lot more time if conditions turn in favour of glaciation.
This post raises an important aspect of the climate change problem, namely that events which would be catastrophic if they occurred, but of which there is a purely academic possibility and a trivial probability under normal conditions of climatic variation, could become less improbable as a result of human-induced climate change. With possibilities such as an interruption of the Gulf Stream or the collapse of the Amazon ecosystem, even a probability of 1 in 100 constitutes an unacceptable risk which we should be prepared to incur significant short-run costs to minimise.
If long term transpiration rates are reduced as CO2 increases then the trees are using less water.
Studies have shown that tree growth is maintained or increased with increased levels of CO2.
Studies have also shown that leaf sizes decrease whilst stomata densities are increased as CO2 increases.
Therefore with increased CO2 plant growth uses resources more efficiently.
The fascist US DEA is still spraying pristine jungles in Columbia. This is not just ecocide but SUICIDE if it continues. This entire area needs to be taken over to stop the war and the fascist DEA neutralized, the red fascist FARC neutralized and the oligarchic fascist puppet US regime nuetralized.
A large UN force could do this and , in fact, MUST do this in order to save the planet. I call on Hugo Chaves to kick out the remaining DEA agents in neighboring Venezuela as a gesture of strong solidarity with the health of the planet and I call again for global humanitarian armed intervention.
This is serious mom.
“but of which there is a purely academic possibility and a trivial probability under normal conditions of climatic variation…”
Look you guys know that nature doesn’t conform to some sort of static equilibrium. To some sort of nice comfy band that it wavers within.
You know this but you talk AS IF thats the case in order to bring your bizzare program off. Its like in the old days where you wouldn’t make the claim that wealth didn’t need to be produced before it was stolen and divided up. You would just talk AS IF that were the case.
Our planet lurches in and out of nasty glaciations. The Earths climate…. without man… is inherently variable. But you are all talking as if all you have to do is stay still and don’t breathe too hard and the planet will keep its climate pretty much where it is now..
This is just not the case.
The Amazon if we stopped burning and bulldozing it might survive with human influence. And it could very well perish without human influence. Since it is a colder planet that is also a drier and more miserable planet. If the CO2 level fell under 200ppm the Amazon would probably die.
If we weren’t here the Amazon might die. But if we are here and putting out CO2 but not bulldozing and burning the Amazon the Amazon that might have died might instead live with the extra plant growth, extra rain and reduced need for water.
You’ve got to all stop talking in this presumptive way. Because the net effect of doing this is for you to all mesmerise eachother. This scientific fraud has gotten such a head of steam that you now all talk in this bizzare way and it serves to hypnotise you.
Snap out of it.
Me I’d want to near-maximise the extent of the rainforests everywhere. I’d want to be buying land on the fringes to expand it even as we exploit areas within.
And we will be more successful in this positive explicit goal if we have more CO2 out there.
If you had a two hundred year goal to Green the entire interior of Australia you are going to get there more easily by maxing out on CO2. By getting it to hydroponic levels. That is to say 1000 ppm to 1500 ppm. That would be the first step to such an ambition.
Step 1.
Allow business to use as much coal as they want.
That would be your first step.
Instead of sitting round pretending that something dies everytime you turn the heater on why not develop some sort of positive goal.
“The fascist US DEA is still spraying pristine jungles in Columbia. This is not just ecocide but SUICIDE if it continues”
Dude. You just got to legalise drugs is all. No need to get violent about it. Just legalize drugs and the DEA will go home and stop ruining these countries.
“The melting ice sheets are a good thing. Because it means we’ve bought ourselves a lot more time if conditions turn in favour of glaciation.”
That is one of the batshit craziest things I’ve read in… well, just about forever.
That Independent article is, typically, pretty sloppy (what do you expect from the home of Robert Fisk?). As you say, the Woods Hole report is less apocalyptic in tone, but also less apocalyptic in its conclusions (e.g. 5 years drought, not 2 for significant dieback of large old growth vegatation, and that under conditions of zero wet season rainfall). Given that this report is the basis of the Indy’s story, there is a lot of journalistic licence being employed. I note they didn’t even bother spelling the researcher’s name correctly. Arrant sensationalism.
Only someone ignorant of the what kind of a life-form Birdie is would say this.
If you have been paying any attention at all you’d know that Birdie is a submarine C02 breather.
Yes, Birdie is a stromatolite!
http://stromatolite.brainsip.com/
Brian, Flannery’s 3rd of three disastrous tipping-points was the release of methane from the sea-floor. (ice cap melts being more of the slow and inexorable kind of disaster, I think, if that’s any kind of comfort.)
wbb, thanks for that. We’ve got painters in at present which is a prelude to unpacking all or almost all of our books.
I decided to delete the second paragraph of your comment, rather than all of it as you suggested, but things are getting pretty repetitive in a way and a bit too personal at times as well for my liking.
I’ll comment on some matters others have raised later.
Check out this discussion from RealClimate – a blog brought to you by real climate scientists.
It’s not as extreme as the Independent article, but still concerned. I read that blog regularly, and it still scares me – but probably more than the occasional regular media sensationalist article, because it piles on the overwhelming scientific evidence that things are happening, and faster than scientists expected (Greenland ice sheet melting is probably the biggest one of these).
Jennifer, thanks for the link.
I have to say that I don’t claim any great knowledge on global warming and climate change. I got my head into it for a weekend a couple of years ago and felt impelled to do a guest post at Quiggin’s place. I normally spend most of my time away from computer screens and indeed reading, so while I’m interested and concerned I can’t really keep up. I found I had RealClimate bookmarked, but I haven’t been reading it regularly.
I got lost there for a while tonight. By following some links I found I shouldn’t worry about polar bears. I do hope the man is right.
I found a fascinating post and discussion on tipping points which brings the whole global warming debate into focus. I’d highly recommend it.
On that thread I was reminded that there are other things to worry about, for example the effects of acidification on plankton and other small critters in the sea.
I also found a response by Daniel C. Nepstad the senior scientist from Woods Hole responding to the alarmist article in the Independent. But it included this:
It’s a worry, but what I’m struggling with is how big a worry is it? How likely is it to happen and what are the implications on the global climate (leaving aside the direct local effects?
I’m not any the wiser really except that it seems that the ice we are skating on is thinner than we thought.
It is clear that there are multiple factors at work. The local destructive activity is probably the worst. The warming of the oceans to the north seems part of the problem. So does the ENSO factor as we seem to be promised more El Nino’s in the future. The new research simply shows that the forest may be more fragile than we thought. And those 73,000 fires last year really worried me.
But in the end it is a case of systems within systems and systems interacting with other systems and all of them chaotic. I thought this comment captured it pretty well.
This is where James Lovelock’s approach goes beyond James Hansen’s, I think. (I quoted Hansen endlessly on the Greenland thread. Hansen says we are now in charge of the climate because what we do makes the difference. Lovelock wouldn’t deny this, nor would he deny the need to take concerted action. His proposals are in fact more radical, but the important aspect is that we should allow Nature the space and scope to repair herself. We need, he says, to effectively vacate a third of the planet, and not just the less useful bits, in order to allow natural systems (which we can never hope to fully understand) to find a new balance.
He says things last really went off the rails 55 million years ago. Then because of methane emissions comparable to the carbon we are putting into the air now (but 30 times more quickly) the temperature rose to 5C higher than now at the equator and 8C higher in the temperate zones. This was very adverse to life. But a more favourable balance was eventually achieved in the carbon distribution, but it took 200,000 years and the important process that turned things around involved the weathering of rocks.
So our future may or may not include an Amazon rainforest as we know it. But I hope we don’t have to go the long way round to lose and regain a liveable planet.
The Independent piece is irresponsible and is typical of too much environmental reporting. If the situation is as serious as green activists would have us believe, why do they feel compelled to paint the lily whenever new research is reported? This sort of thing is directly responsible for much of the skepticism about global warming and is one reason why groups such as Greenpeace have so little credibility.
Bismarck. I agree, but I was curious, confused and a bit amused when the learned climatologist who wrote the post at the RealClimate identified the Independent article as “good” in it’s incarnation at Climate Ark. Then when commenters protested he defended himself instead of saying, “Oops, I stuffed up!”
Clearly the notion that the planet will become “uninhabitable” is unwarranted and the RealClimate author makes the point later in the thread that no scientist would go there.
Brian, there is an interesting debate at the link you provided to RealClimate concerning the legitimacy or otherwise of alarmist reporting. Some commentators there seem to think it is OK to publish any old tosh if it scares people into taking action. I’ve been around long enough to have seen alarmist scenarios come and go, and the result is more likely to be skepticism and inertia.
As an update, there was an interesting segment on PM yesterday. Two of the guests were Professor of Environmental Science at Britain’s University of East Anglia, Andrew Watson, and the Professor of Climate System Dynamics at Exeter University, Peter Cox:
They are particularly concerned about secondary feed-back loops kicking in.
The segment foreshadowed a session on climate change on the Science Show today (12.10pm repeated 7.10pm Monday).
Be there, if you’re concerned about the future of the planet!