Tuesday, June 19, 2012

Eureka! It's a bathtub budget!


When Archimedes noticed the water level in his bathtub go up, he had an "ah-ha" moment. The bathtub holds a limited amount of stuff whether it is water or humans. When you go over the limit, the bathtub overflows. His insight was to recognise that it doesn't matter whether it is water or a grubby human body, when you put too much in, the water spills over the edge.

Similarly, the atmosphere can hold a limited amount of greenhouse gases (GHGs) before climate systems go crazy. It doesn't matter who puts them there, when there's too much we get climate catastrophe — droughts, ocean acidification, rising sea levels, storms and floods.

To stop the water spilling onto the bathroom floor, you have to turn the tap off. Even a small drip will cause the bathtub to overflow eventually. It's the same with the atmosphere, we will have to stop GHG emissions altogether or the climate system will go crazy. Carbon sinks don't work like a bath drain because they developed over millennia to balance the amount of natural CO2 emissions and they can't cope with the extra emissions humans have been putting out from fossil fuels. They can't drain it out as fast as we're putting it in, so the water level has been inching higher every year.

How soon do we need to turn off the tap and reduce our GHG emissions to zero? That depends on how close the bathtub is to overflowing. Is it half-full, or lapping the rim?

The best scientific advice is that the size of the GHG tub is about 350 ppm of CO2-e gases. This is a lot higher than the pre-industrial level of 280 ppm when the GHG bathtub was nicely balanced.  For thousands of years GHGs dripped into the tub and the leaky plug (carbon sinks that absorbed carbon dioxide) let them out  at the same rate. 350 ppm is higher and it will have some climate impacts, but they are likely to be manageable.

Right now, measurements of 400 ppm CO2 are starting to come in. This means that the tub is already overflowing. We have no time to waste to move to zero emissions as quickly as possible.  If we don't, we are driving headlong into catastrophe which guarantees that we'll have a big clean up job to do.

All our policies should be directed towards this bathtub budget. But how do we calculate our share of the bathtub budget? For social justice to prevail the only fair measure is to allocate a carbon budget for each per person on the planet. Based on 7 billion people, this works out to be about 5 tonnes of CO2-e per year (c.f. Serbia or Argentina). When world population has grown to the projected 9 billion, then our per-person budget will be 3.9 tonnes of CO2-e per year (think of Jordan or Turkey).

This means that Australia has to move quick-smart from something like 28 tonnes per person (the highest among OECD countries) down to 5 tonnes per person, and then be prepared to shave off a bit more.

Targets like "5% lower in 10 years time" aren't going to stop the bathtub from overflowing any time soon.

6 comments:

  1. According to a presentation from David Karoly that I heard the other night:
    When the greenhouse gases that aren’t CO2 are counted into the equation (as they must be) the world is ALREADY PAST the magic 450ppm thresh-hold that was supposed to give us a 50% CHANCE of stabilizing global warming at 2ºC. This is the concentration beyond which uncontrollable climate change becomes a probability.

    We know that when the atmospheric greenhouse gas burden consistent with halting global warming by 2030 is divided by the world’s population is divided by the world’s population we get an individual allocation of greenhouse gas consistent with halting global warming at the ‘safe’ +2ºC threshold.
    When this is multiplied by the population of a country we get a NATIONAL allocation. Australia exceeded its NATIONAL allocation in 2007! TWENTY THREE YEARS AHEAD OF TIME! Viewed in this light we are already carbon debtors soaking up the allocation of the world’s poorest nations to sustain our destructive lifestyle.

    As if this wasn't enough we are planning a gigantic expansion in our contribution to global coal and gas consumption that will make us a larger exporter of greenhouse gas emissions than Saudi Arabia. With the world already past the safe greenhouse gas limits and Australia already sponging up the emissions that are supposed to underpin a a modicum of development for the world’s poorest nations we are intending to throw a bucket of kerosene on the global barbecue.

    All of the above is well known, widely accepted, scientific fact that somehow doesn’t get much of an airing in the mainstream media.

    Anyone who gives a damn about their kids’ futures should inform themselves (not difficult). Then get out there and beat down your local member’s office door, shout the message at him/her and keep it up until we get effective action across the board. Without this the battle is already lost.

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  2. Ah, yes, thank you for the correction. The recent Arctic measurements of 400ppm are CO2, not CO2-e, so they don't include methane, nitrous oxide, etc.

    You are right that we need to get our MPs informed. I currently have an ongoing correspondence with mine. I hope I'm chipping away at his misconceptions, though I fear that this 'debate' is not likely to be won on the basis of evidence. I think it will take one or more major climate catastrophes. Paul Gilding makes sense when he describes a response similiar to all-out war footing. He puts 2018 as a likely date. Now THAT will be interesting.

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  3. I enjoy the positive atmosphere of your posts. I've been chipping away at this for some years now and find myself getting more and more pessimistic. I wish you luck with your correspondence with your local MP. I exchanged letters with Lindsay Tanner (who was my Federal MP). Tanner was/is intelligent and reasonable but was bound by Party policy (a Party that also included my current MP Martin Ferguson) and my letter/email writing to politicians took quite a lot of time and achieved absolutely nothing. This decided me to start a blog, try to help get Adam Bandt elected and get more active in my local climate change group. Best return on effort by far came as a result of Adam's election. My involvement was tiny but the dividend has been great I think.

    The climate change group tried a different approach when it came to our local State (Labor) MP under the Bracks-Brumby State Labor government. We picketed his office every Wednesday afternoon for a couple of hours for more than a year waving banners, getting passing cars to toot, chalking slogans on his footpath and handing out fliers criticizing Labor's climate change efforts. He hated/hates us for this but as a fundamentally decent person he put up with it and I think this pressure did translate into some action at State level. Ferguson on the other hand as a fundamentally dreadful person simply calls the police. My point is that I think this sort of publicly visible criticism might get some action where I don't really think personal letters and submissions on White Papers etc (written a few of them also) have any real effect at all. It is very difficult. Our possibilities to influence policy outcomes are so limited.

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  4. Hi Doug... I'm a newcomer to environmental activism, so maybe I haven't been worn down yet! Or maybe I have low expectations.

    By and large, I think that the political process is hostage to inertia and powerful lobby groups. It is something of a wonder that we've got the carbon tax at all.

    This is a learning process for me. Just now, I'm in a place where I think that govts will be spurred to strenuous action by some major catastrophe, i.e. an external event. Most of what we're doing now is a kind of preparation or rehearsal for the main game to follow.

    I have to say I was gobsmacked by the amateurishness of the Draft Energy White Paper. God help us if this is the calibre of professionalism in the Dept of RET. I'm a bit puzzled, because I have the impression that the fearless bureaucrats in Treasury have been world class in their policy recommendations and their ability to persuade politicians on both sides to implement major reforms. Clearly talent is not spread evenly across Canberra govt depts.

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  5. I’ve also been thinking a lot about Paul Gilding’s book and his fundamental message that things are going to get nasty (as we all suspect) but that we will see the danger in time and respond effectively as we did in the past in relation to (his example) WW2. I admire Gilding and what he has achieved. I respect his analysis of our situation but I've always been uncomfortable with his message that the penny will drop in time and that we will pull through.

    I think this is why. Laura Tingle in her excellent Quarterly Essay examines the historical roots of our sense of entitlement and attributes it at least in part to our expectation that governments will look after us (take care of things).

    Historically we regard politicians not as our betters but people just like us who we elect to protect our interests and who we expect to hear relatively little from except around election time. The 24 hour news cycle has made this impossible but the expectation still remains and nothing apparently irritates us more than having the political circus permanently front and centre in our newspapers and on our TVs. We expected Rudd to 'fix' the climate problem but he dropped the ball and we lost interest. But the anxiety about climate change remained – someone should be doing something about it but who and what? It's all too hard let's think about something else – but the anxiety lingers. Now comes the eminently well qualified and very articulate Paul Gilding to say yes it will get nasty but DON'T WORRY WE WILL ACT IN TIME. To many this could be taken to mean THE GOVERNMENT will do something. I think the grateful relief evident in many on-line responses to Gilding's work suggest that this is what has been understood.

    In this culture where we do not easily or often take to the streets en masse to demand action on an issue, we are glad to be reassured that we will not have to do anything much this time either. Although I'm sure that that is not what PG the old activist is advocating I have this sneaking suspicion that that is behind much of the very positive response to PG's book. I also think that whether it is unintentional or not this is a very dangerous message to spread.

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  6. Yes, I agree with you there. I'm getting to the final chapters of 'The Great Disruption' and I think he's hopelessly fluffy and naive. He imagines that catastrophe will cause us all to share??? Nope, catastrophe will cause us to pull up the drawbridge and look after our own.

    I much prefer Gwynne Dyer's "Climate Wars" because he's much more realistic and a much better writer!

    Still, I think they are both right in their assessment that mitigating actions will be weak until there are some major catastropic weather-related events. The Rio summit shows us that govts are making less commitment than ever before. Compared with others, Aust looks good with its Carbon Tax and new Marine Reserves. But so much more is needed! Once social fabrics start to breakdown there will be no hope of global cooperation. Indeed, I think we are already seeing this.

    Last week I was browing online for a parcel of arable farmland in Tasmania. What better bequest could I make to my descendents? I probably won't do it, but it definitely had appeal.

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