22 January 2009

350 is the wrong target: put the science first

During 2008, US environment writer Bill McKibben and colleagues established the climate activist group 350.org, with the aim of spreading the message that policy targets need to reflect the scientific imperative.

The campaign has harnessed many people and organisations' collective energy and has been successful in the United States, and internationally at such forums at COP14 in Poznan, in helping to educate people that targets such as 450 ppm (per million) carbon dioxide in the atmosphere are not acceptable, that the current level of carbon dioxide (387 ppm) is too high for a safe climate, and so our action must be zero emissions and a cooling of the planet.

The important question now is whether 350 is a target based on the science, or one that is judged to be politically appropriate.

The question now, as Obama takes office, is what really need to be done. In his
An open letter to President Obama on how to make the climate challenge real and urgent to Americans, Ken Ward notes that:
The US cannot muster the resources and resolve necessary to lead the world to safety if your administration does no more than plump domestic "green jobs" and "equitable stimulus" programs – progressive rhetoric for the stump and nothing more – and endorse decades-old cap & trade policy ginned up by environmentalists looking for policy acceptable to corporate "climate action" partners.
As our first organizer President, you know that the right course of action is not to tinker with the details of policy… but to rewrite the terms of the debate. The problem is that there is no conflict and it is therefore difficult to bring the resources of the "bully pulpit" to bear.
The bold move is to do nothing.
It will require immense determination to forestall the political forces coiled in anticipation of quick administration action on climate, but you must stiff-arm your advisers, step outside the Congressional climate quagmire, leave environmentalists hanging, and delay international engagement.
It is crucial that the nation does not move directly from the old conflict, "is global warming real?" directly into action, without first facing the terrible questions "how bad is it?" and "what do we need to do?
So what do we really need to do?
The target of 350 ppm was embraced by Al Gore at COP14 in Poznan: “Even a goal of 450 ppm, which seems so difficult today, is inadequate,” said Gore, adding we “need to toughen that goal to 350 ppm.” In a blog from Posnan, Australian Conservation Foundation (ACF) CEO Don Henry called Gore’s speech “the high point” and wrote that Gore “said that even stabilizing greenhouse emissions at 450ppm was inadequate and that the science was indicating the we would need to move to 350ppm.” But Henry has not indicated whether ACF, whose corporate branding uses Gore prominently, would adopt this target or whether ACF’s Gore presenters would be permitted or encouraged to include Gore’s new target in their public presentations.

In Poznan the Least Developed Countries caucus and the International Youth Climate Network supported the 350 target, and 350.org used the occasion to announce an international day of action on 24 October 2009 to spread the number.

Why 350? The website proclaims 350 as “The most important number on earth’’. [
For a more detailed analysis of the genesis of the 350 target, see here]. McKibben says that:
A year ago, nobody had ever heard of 350. But it turns out it’s the most important number on the planet... If people around the world know nothing else about global warming, we need them to understand that 350 represents a kind of safety – if we can get that message across, then they’ll demand 
dramatic action from their leaders
In a recent article for Mother Jones, McKibben explains why:

The final piece of the puzzle came early this year, and again from James Hansen. Twenty years after his crucial testimony, he published a paper with several coauthors called ‘Target Atmospheric CO2’. It put, finally, a number on the table-indeed it did so in the boldest of terms. ‘If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted,’ it said, ‘paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm’.
But that is only half the story. Here’s what else Hansen et al. said (emphasis added) in their article in Open Atmos. Sci. J. 2:217-231:
Equilibrium sea level rise for today’s 385 ppm CO2 is at least several meters, judging from paleoclimate history. Accelerating mass losses from Greenland and West Antarctica heighten concerns about ice sheet stability. An initial CO2 target of 350 ppm, to be reassessed as effects on ice sheet mass balance are observed, is suggested.
It is important to note that this paragraph is not about the Arctic sea-ice tipping point, it’s about Antarctica. Hansen explains in the same article that 350ppm is a precautionary target to stop global loss of ice-sheets, because the paleoclimate record shows 450ppm ± 100ppm as boundary for glaciation/ deglaciation of Antarctica. In the next paragraph, attention turns to the question of Arctic sea ice:
Stabilization of Arctic sea ice cover requires, to first approximation, restoration of planetary energy balance. Climate models driven by known forcings yield a present planetary energy imbalance of +0.5-1 W/m2. Observed heat increase in the upper 700 m of the ocean confirms the planetary energy imbalance, but observations of the entire ocean are needed for quantification. CO2 amount must be reduced to 325-355 ppm to increase outgoing flux 0.5-1 W/m2, if other forcings are unchanged. A further imbalance reduction, and thus CO2 ~300-325 ppm, may be needed to restore sea ice to its area of 25 years ago.
The central point is that Arctic sea-ice is undergoing dramatic loss in summer, having lost 70-80% of its volume in the last 50 years, most since 2000. Without summer sea-ice, Greenland cannot escape a trajectory of ice-sheet loss leading to an eventual sea-level rise of 7 metres. Regional temperatures in the Arctic autumn are already up about 5C, and by mid-century an Arctic ice-free in summer, combined with more global warming, will be pushing Siberia close to the point where large-scale loss of carbon from melting permafrost would make further mitigation efforts futile. As Hansen told the US Congress in testimony last year, the “elements of a perfect storm, a global cataclysm, are assembled”.
In short, if you don’t have a target that aims to cool the planet sufficiently to get the sea-ice back, the climate system may spiral out of control, past many “tipping points” to the final “point of no return”.
And that target is not 350ppm, it’s around 300 ppm.

Hansen says Arctic sea-ice passed its tipping point decades ago, and in his presentations has also specifically identified 300-325ppm as the target range for sea-ice restoration (see slide image), as did the paper quoted above. This view, by probably the most eminent climate scientist in America, is reinforced by Hans Joachim Schellnhuber, head of the Potsdam Institute and climate adviser to German Chancellor and the EU, who likewise is one of Europe’s leading climate scientists. On 15 September 2008, David Adam reported:

Professor John Schellnhuber, director of the Potsdam Institute for Climate Impact Research in Germany, told the Guardian that only a return to pre-industrial levels of CO2 would be enough to guarantee a safe future for the planet... He said even a small increase in temperature could trigger one of several climatic tipping points, such as methane released from melting permafrost, and bring much more severe global warming. ‘It is a very sweeping argument, but nobody can say for sure that 330ppm is safe,’ he said. ‘Perhaps it will not matter whether we have 270ppm or 320ppm, but operating well outside the [historic] realm of carbon dioxide concentrations is risky as long as we have not fully understood the relevant feedback mechanisms.
So 350 ppm is the wrong target because 350 ppm CO2 cannot restore the Arctic ice to its full extent. The people who run 350.org probably now recognise that, because their language is changing. One of their slides used to say: “We need to be here: 350”, it now says “we need to be lower than: 350ppm”. McKibben now talks about 350 ppm as being “the upper limit”, and in a recent radio interview said pre-industrial levels might be the only safe zone. But it’s too late to advocate targets that are only a signpost towards the target we really need to get to.
Sorry, Bill and the crew at 350.org, you’re wrong about 350 being our campaign target for 2009 and the lead-up to Copenhagen. The most important number of earth is 300. That’s what Hansen is saying, that’s what Schellnhuber is saying. There’s no point campaigning on an inadequate target. We only get one chance at this, and advocating targets that will still fail to fully solve the problem is the most de-mobilising action we can take.
Target 300 puts the science first.
Interestingly in Australia, where I am based, 350 has not gained wide appeal, with most of the grass-roots climate action groups adopting a 300 ppm target, consistent with the propositions elaborated in Climate Code Red.
David Spratt
22 January 2009


  1. The critical point emphasized so well here - which many, particularly in the US, still find difficult to come to terms with - is that we're down to one shot, at best.

    Always nice to be quoted, but don't want to leave the impression that I've urged our new President to literally do nothing. My letter to President Obama includes a short agenda the President could implement directly that would go a long way to wrench the US toward reality. See http://gristmill.grist.org/story/2009/1/19/135710/112

    One item is to ask the National Academy of Sciences to review current climate science and comment on a pre-industrial, 265-275 ppm goal.

    It should be noted that McKibeen et. al. adopted the 350 ppm goal at Hansen's recommendation. Now Hansen has retreated to 300 ppm, but is there really any argument for a standard other than a return to atmospheric equilibrium before humankind started messing with it?

  2. "Ultimately, responding to global warming is a political issue." --Lorrie Goldstein, Sun, 16 March 2008

    "What I learned in the past few years is that politicians often adopt convenient policies that can be shown to be inconsistent with long-term success, given readily available scientific data and empirical information on policy impacts." --Dr Jim Hansen, NASA

    Any carbon diet strategy would be dependent upon clean coal:

    "The vast majority of new power stations in China and India will be coal-fired; not "may be coal-fired"; will be. So developing carbon capture and storage technology is not optional, it is literally of the essence." --"Breaking the Climate Deadlock," Tony Blair, June 26, 2008

    But, Vaclav Smil, an energy expert at the University of Manitoba, has estimated that capturing and burying just 10 percent of the carbon dioxide emitted over a year from coal-fire plants at current rates would require moving volumes of compressed carbon dioxide greater than the total annual flow of oil worldwide -- a massive undertaking requiring decades and trillions of dollars. "Beware of the scale," he stressed."

    In other words, it is doubtful that even the politically unrealistic cuts US President Obama committed to support in the campaign will significantly slow global warming.

    "I'm going to tell you something I probably shouldn't: we may not be able to stop global warming. We need to begin curbing global greenhouse emissions right now, but more than a decade after the signing of the Kyoto Protocol, the world has utterly failed to do so. Unless the geopolitics of global warming change soon, the Hail Mary pass of geoengineering might become our best shot." --Bryan Walsh, Time Magazine, 17 March 2008

    "The alternative (to geoengineering) is the acceptance of a massive natural cull of humanity and a return to an Earth that freely regulates itself but in the hot state." --Dr James Lovelock, August 2008

    "The Panel (on Policy Implications of Greenhouse Warming) calculated that adding stratospheric aerosol dust to the stratosphere would cost just pennies per ton of CO2 mitigated." --"The Incredible Economics of Geoengineering"

  3. Aiming for 350ppm Equivalents would be a far better target. Al Gore wasn't specific about whether he was referring to 350 CO2 or 350 CO2 Equivalents. Hopefully this was a deliberate and well informed decision, with a view to making it specific to Equivalents at a later date.

    IPCC report that stabilising at 350ppm Equivalents would lead to mean global temp rise of 0.6-1.4.

    Even this temperature rise risks triggering further feedbacks, leading to far higher temperatures than anticipated. Significant feedbacks are already in progress from only 0.5 to 0.7 DegC mean temp rise. We must cool the Arctic urgently, and may need geo-engineering technologies to back up the reduction in emissions.

    The most important target is to start to cut total global CO2 emissions now, ie this year, and hopefully, last year. Long term stabilisation targets are irrelevant unless we start to cut emissions immediately. Hopefully this awful economic situation can be the turning point for creating a new stronger, fairer and sustainable economy which reduces consumption and pollution.

    Please see our 90 second film of children singing their message for world leaders: www.singfortheearth.org

  4. Climate models, for all their success, seldom capture the known tendency of the real system to shift abruptly at tipping points. After three decades of relatively flat global temper¬ature as the CO2 rose from 308 to 326 ppm, there was a marked shift in 1976 to a rising global fever. This suggests that a 350 ppm target is not low enough.

    Seven years into this new climate regime, global drought suddenly doubled and has never returned to the earlier baseline (from 1950 to 1982, the global land surface in severe drought stayed near 14 percent). This doubling in 1983 occurred when CO2 was only 342 ppm.

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  6. It seems to me the good thing about the 350 target is that it is way less than the present level which is already over 10% higher. This makes the urgency of the problem much more obvious than the 450 ppm target which had been adopted by many countries.
    As for how to reduce the CO2 levels quickly enough, the best expostition I have read is by Minqi Li at :

    Ricky Ward, Chiang Mai

  7. Agree with the above comment..keep sharing..!

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  8. more reasons to rename Industrial Revolution ==> Fossil Fuel Revolution!


  9. I have enjoyed reading your blog. Unfortunately, I do not believe that anyone has enough authority or credibility to grab people's attention. Everyone seems to be playing a different tune. But I agree that there should be an initial target set.

  10. Thank you for posting such article. Its great to see such eye opening post.There are still many things to learn and more surprises to come.

  11. Thats an interesting post. It was worth visiting your blog and I have bookmarked your blog. Hope to visit again.

  12. Very insightful, I really enjoyed reading it. I hope to read some more this week!

  13. Hi david.. Thanks for a very enlightening post :D


  14. Hello, Good article, read with great interest. Really its great to be visiting your blog, Thanks very much! keep posting....

  15. Hi David. The 350.org is the coolest organization that I have ever heard. May they be strong and united always. Thanks.

  16. Incidentally, I like the way you have structured your site, it is super and very easy to follow. I have bookmarked you and will be back regularly. Thank you
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