Gore embraces 350 ppm target at Poznań


[This post is from Bill McKibben in Poland. For background on the science behind the 350 target and the challenge it poses see “Stabilize at 350 ppm or risk ice-free planet” and “The truth about stabilizing at 350 ppm.” Video of Gore is here.]

Al Gore gave the international climate talks in Poznan a new set of marching orders this afternoon, declaring that old targets for fighting global warming had been made obsolete by new science and that 350 parts per million co2 was the new standard for which the world must aim.

“Even a goal of 450 parts per million, which seems so difficult today, is inadequate,” said Gore, adding we “need to toughen that goal to 350 parts per million.”

The number itself is less than a year old–NASA scientist James Hansen first set it as a goal in a scientific paper last winter. But in the months since, a global effort led by has spread the goal with rallies and demonstrations on every continent.

“Our efforts reached a new level this afternoon, when Al Gore changed the decade-old goal for a new climate agreement,” said co-founder Bill McKibben. “The world now has a new target, one that negotiators must figure out how to meet by next year in Copenhagen if those talks are to be a success.” also used the occasion to announce an international day of action to spread the number next October 24, with events planned from high in the Himalayas to undersea on the Great Barrier Reef. “We need to take this movement for survival to the farthest reaches of the planet,” said Ely Katembo, organizer from the Democratic Republic of the Congo. “We’re talking to everyone, from wired teenagers in Europe to Masaii tribesman on the plains of Kenya.”

The response to Gore’s remarks highlighted growing international acceptance of the goal–his call for a 350 target drew the longest applause of his speech.

“Actions are already streaming into the website from Norway, Korea, Ecuador, and more” says Jon Warnow, web strategist for the project. “16 years ago, when the Kyoto protocol was debated, this sort of campaign wouldn’t have been possible. Now, with the internet, we have the tools we need to organize at the scale of the problem we face.”

A variety of international voices spoke out in support of‘s call to action. International human rights icon, Desmond Tutu, called the campaign, “an effective way to take action to turn around the climate crisis.” Leading United Kingdom environmental author, George Monbiot wrote, “This is a great initiative, which all those who care about the future of humanity should support.” More “350 Messengers” are displayed on the website.

“A year ago, nobody had ever heard of 350. But it turns out it’s the most important number on the planet,” said McKibben. “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.”

13 Responses to Gore embraces 350 ppm target at Poznań

  1. Pierre-Emmanuel Neurohr says:

    Thirty years from now, people will look back and be completely amazed that so many people decided to save the climate by using the most effective climate-destroying machine, aka “plane”. A minority of human beings on the planet use this climate-destroying machine, and they keep telling us they’re doing so much to save the climate. Are we supposed to clap our hands?

    When will we see a coherent message emerge with environmentalists protesting the destruction of the climate by pledging to stop using the most efficient climate-destroying machine? Or is it just too difficult to understand that you cannot TELL anybody to stop destroying something if you, as part of a minority of humans, ACT to destroy it?

  2. Rick C says:

    I don’t know about 350 Joe. I would love for that to happen. It would be the best Christmas present I and the rest of the world could get if the US was dedicated to reaching that 350 ppm goal but I ran a speach by Steven Chu from the 2007 Meeting of the Minds conference and he says under the most optimistic scenario it would be difficult to leave it at below 500 ppm. That’s pretty sobering news.

  3. paulm says:

    Ironic that jets might have helped masked or delayed GW!

    They may also play a big part in a tech solution (if) when we come to that.

  4. paulm says:

    Rick C I think we all kinda know its fingers crossed now.

  5. Since we are already over 380ppm and since has excluded nuclear power, and since has not, as far as I know, adopted a scheme to remove CO2, how does think we are going to do it?

    I would like to lower the CO2 to 350ppm, but Steve Chu is realistic unless people are ready for much more drastic and severe action than has suggested. Removing CO2 from the air would require an enormous energy and money expenditure. Consider devoting NASA’s budget or the Defense budget to the project. It would be money well spent, but it will never get thruough congress. I am waiting for a realistic plan from Until they have one, why should anybody listen to them?

    PS: Air travel is almost irrelevant. The #1 source of CO2 is coal fired power plants. The #2 source is industrial processes. The source of energy that produces the least CO2 per kilowatt hour is nuclear. The cleanest and safest is nuclear. Nuclear reactors can be made in factories. Nuclear fuel can be recycled. There is not enough wind. Solar never works at night.
    PPS: Coal contains uranium.
    What will actually happen: The rainfall bands in the midwest will move, disrupting agriculture. Food production will stop. Civilization will fall.

  6. Wonhyo says:

    Is 350 ppm *low enough*? As I understand it, the pre-industrial age global mean was about 275 ppm. If climate change hadn’t already progressed to where it is today, with the beginnings of feedbacks, I can believe we may be able to stabilize at 350 ppm. Given where we are now, I would feel much safer if we added a margin of safety by going well below 350 ppm.

  7. Pierre-Emmanuel Neurohr says:

    Asteroid Miner wrote: “Air travel is almost irrelevant.”

    Right. “Almost”. Says an air travel user? Sure. Dream on, and feel good about participating in the most efficient way in the destruction of the climate.

    “Aviation already accounts for 13% of the UK’s total climate impact, and is now the fastest rising cause of greenhouse gas emissions in the UK. The Tyndale Centre in Norwich is now predicting that aviation emissions on their current trajectory will actually account for up to 100% of the government’s carbon budget by 2050. In other words, even if we retired every car from the road, unplugged every electronic device and closed every factory, we would still not meet our climate change targets because of aviation.”

    A flying leap, Michael Meacher (former UK environment minister), The Guardian, Nov. 12th, 2008.

  8. David B. Benson says:

    I opine that in the long run we will want to restore around 300 ppm CO2e.

  9. Peter Wood says:

    The reason that 350 ppm CO2 has been chosen is that in James Hansen’s paper Target Atmospheric CO2: Where Should Humanity Aim? he states:

    If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm.

    and later states

    We suggest an initial objective of reducing atmospheric CO2 to 350 ppm, with the target to be adjusted as scientific understanding and empirical evidence of climate effects accumulate.

    What Hansen appears to be saying is that 350 ppm is an upper bound, above which we risk changing the planet quite dramatically. One of the main reasons for this feedbacks involving loss of albedo because of loss of ice. Obviously any target below 350 ppm is safer (and harder to reach).

    What sort of emissions reductions are required to reach 350 ppm? The following papers are a good place to start:

    * Meinshausen et al. (2006) Multi-gas Emissions Pathways to Meet Climate Targets Climatic Change 75: 151–194
    * Hare and Meinshausen (2006) How Much Warming are We Committed to and How Much can be Avoided? Climatic Change 75: 111–149
    * Wigley et al. (1996) Economic and environmental choices in the stabilization of atmospheric CO2 concentrations Nature 379, 240 – 243

    The paper by Meinshausen et al suggests that we should reduce CO2 emissions by slightly more than 5% per year to get to 350 ppm. Some trajectories in other papers have less reductions by 2020, but more dependence later on technologies that remove carbon from the atmosphere (e.g. biomass burning with carbon capture and storage).

  10. Barry Brook says:

    Tom Wigley includes a 350ppm mitigation scenario in the latest version of MAGICC – so you can run the AR4 CMIP emulation yourself and see the result:

  11. Peter Wood says:

    Thanks Barry, MAGICC is a useful tool.

    One thing that is worth mentioning is that Hansen suggests 350 ppm because palaeoclimate data suggests that climate sensitivity is 6 degrees C when taking into account ice sheet effects. A scenario that might stabilise at 350 ppm at a sensitivity of 3 degrees C will have more carbon cycle feedback effects with a higher sensitivity, and stabilise at a higher concentration. MAGICC seems to suggest that at a sensitivity of 6 C, the 350 scenario will stabilise at 370-380 ppm.

    This effect is much more serious for higher stabilisation targets of course.

  12. It is not just setting the right target …… it is also about getting there …
    I made a presentation at the Econcern event at Poznan indication that we should work on the supply as welll as on the much larger demand side of CO2 in the atmosphere in order to control the level.
    Video is posted at

  13. M. Kjonaas says:

    Rather than quoting ppm it is much better understood by the general public when the CO2 content of air is stated as 0.035%. That is a very small trace amount of CO2 which cannot possibly affect our climate.
    CO2 in the air is essential for plant life and life as we know it. A much larger amount of CO2 would promote faster growth of food plants.