Current CO2 concentration in the atmosphere

Simply irreversible

So, one might ask oneself, just how urgent is our climate change situation? Surely it’s not, you know, time to panic or

Global Warming Close to Becoming Irreversible: Scientific American:

The world is close to reaching tipping points that will make it irreversibly hotter, making this decade critical in efforts to contain global warming, scientists warned on Monday.

Scientific estimates differ but the world’s temperature looks set to rise by six degrees Celsius by 2100 if greenhouse gas emissions are allowed to rise uncontrollably.

As emissions grow, scientists say the world is close to reaching thresholds beyond which the effects on the global climate will be irreversible, such as the melting of polar ice sheets and loss of rainforests.

“This is the critical decade. If we don’t get the curves turned around this decade we will cross those lines,” said Will Steffen, executive director of the Australian National University’s climate change institute, speaking at a conference in London.

For ice sheets – huge refrigerators that slow down the warming of the planet – the tipping point has probably already been passed, Steffen said. The West Antarctic ice sheet has shrunk over the last decade and the Greenland ice sheet has lost around 200 cubic km (48 cubic miles) a year since the 1990s.

Most climate estimates agree the Amazon rainforest will get drier as the planet warms. Mass tree deaths caused by drought have raised fears it is on the verge of a tipping point, when it will stop absorbing emissions and add to them instead.

Around 1.6 billion tonnes of carbon were lost in 2005 from the rainforest and 2.2 billion tonnes in 2010, which has undone about 10 years of carbon sink activity, Steffen said.

One of the most worrying and unknown thresholds is the Siberian permafrost, which stores frozen carbon in the soil away from the atmosphere.

“There is about 1,600 billion tonnes of carbon there – about twice the amount in the atmosphere today – and the northern high latitudes are experiencing the most severe temperature change of any part of the planet,” he said.

In a worst case scenario, 30 to 63 billion tonnes of carbon a year could be released by 2040, rising to 232 to 380 billion tonnes by 2100. This compares to around 10 billion tonnes of CO2 released by fossil fuel use each year.

Once again, let me remind you, dear readers, that the permafrost number we see quoted all the time is 1,600 billion tons of carbon, not CO2. Even making the generous assumption that whatever portion of that carbon is liberated turns into CO2 and not the much more problematic (in the short run) CH4, then we’re talking about a total store of 5.9 trillion tons of CO2 equivalent.[1] Liberating even 0.1% of that each year, far less than the figures speculated about above, would add about 5.9 billion tons of CO2 to the atmosphere, or almost exactly the net greenhouse gas emissions of the entire US for 2010.[2] So, as we struggle to make incremental reductions in our global emissions (which are still rising, despite our decidedly sub-optimal efforts), imagine adding an additional US, emissions-wise, to the equation every year. That would require the entire world to wipe out all of our emissions in a very short time frame to avoid a nightmarish outcome. And you thought “80% below 1990 levels by 2050″ was a really tough prescription.

Before the Usual Suspects start claiming I’m being “alarmist”, let me explicitly point out that I’m not saying the liberation of any specific percentage of the Arctic carbon is a sure thing, but we do know that thanks to the albedo flip that region is warming much faster than the places where most of us live. And as someone (Richard Alley?) once pointed out so eloquently in a Congressional hearing, “it gets warm… ice melts”. So there is surely at least some CO2 and CH4 being released from the Arctic permafrost; like so many other critically important details in climate science we simply don’t know with any confidence how much or how it will change with just a bit more warming. We haven’t seen a smoking gun signal in the global atmospheric CO2 numbers, so there’s nothing “big” happening on this front yet. Similarly, we’ve had reports of CH4 releases from Siberian hydrate deposits, but those emissions don’t seem to be enough to move the needle on the global figures. Considering the uncertainty and the potential for a massive warming surge from either of those sources, this is about as close to playing Russian Roulette with our future as one could imagine.

I would also point out that the article above refers to the legendary 2C line separating “some warming” from “catastrophe”, or however you’d care to phrase it. This is a highly dubious way to view our situation simply because there’s precious little hard evidence that we can warm the biosphere by 2C and not cause immense human suffering. If anything, the evidence is accumulating that the earth system is more sensitive to disruption than thought, with more change per unit of warming and more amplification from reinforcing feedbacks than expected. There has been an effort to use a guideline of 1.5C (at an atmospheric CO2 content about 40ppm below our current level) instead of 2C[3], but it seems highly doubtful that the major emitting countries will agree to that reformulation, as it’s simply too hard.


Bonus points for anyone who read the title of this post and instantly flashed back to Robert Palmer’s “Simply Irresistible” video, which should have won a special Grammy for the dancers. As the song says, “She’s so fine, there’s no telling where the money went” — nope, no way to see that as a metaphor for our climate situation…


[1] If you want to assume some of it will be methane, which it surely will, then take that portion of the 5.9 trillion tons and multiply it by 20 or 25 to account for the greater global warming potential of CH4. Consider this a warning: It doesn’t take much number fiddling before you can scare yourself spitless.

[2] The actual US number is 5.823 billion tons. See Table ES-2 in the US EPA’s 2012 Draft U.S. Greenhouse Gas Inventory Report.

[3] Perhaps you’ve heard of the main group pushing this idea? Does “350.org” ring a bell?

8 comments to Simply irreversible

  • Congratulations! You’ve written the first article that’s managed to make me feel actually physically sick. The thought of triggering an unstoppable outpouring of permafrost carbon; once triggered, nothing we can do but watch…

  • Sasparilla

    Good to see the scientists saying what many of us have felt for a while now and these guys are still thinking 2 degrees C is a safe number…as its appearing that it probably isn’t.

    It’s a very ugly situation we’ve put ourselves in. Hard to see the GOP changing their stance this decade with the internal powers of that party that want things continuing as they are – I hope I’m totally wrong on that.

  • Lou

    Sorry, Dan. In all sincerity, I try hard not to be too bleak on this blog, but there are times when the simple math is enough to make some people (e.g. me) want to get on the roof with a bullhorn and start asking everyone within earshot if they have any clue about what we’re doing to ourselves.

    I realize how often I repeat some of the same messages here, like the business about “love is fleeting but atmospheric CO2 is forever”, but there is a handful of unyielding facts we simply can’t ignore, that CO2 one being a prime example. We talk a lot about climate change deniers, but they’re just a tiny number of people compared to the vast number of people in the US who are completely disengaged from climate and energy issues. That disengagement is effectively its own form of denial, as it lets the status quo, i.e. business as usual, continue, with all the nasty implications everyone here can name.

    I’ve mentioned Paul Gilding’s book The Great Disruption numerous times, and I really hope people take the time to read it. While I don’t agree with everything he says, I think he comes the closest of any published author I’ve seen to telling the naked truth about not just climate change but what it will take to push us into taking substantive action to combat it. His conclusion is that we’ve already had enough wake up calls (Katrina, etc.) to do the trick if we were open to it, but clearly we didn’t wake up so it will take a change in us before we listen to the plainly evident changes and impacts all around us. I very reluctantly agree. So how does that sea change in our world view happen? It will only come to pass in response to real world events. That means a very slow awakening — likely 20 years or more — which is far too long, or something so massive that it jolts us out of the mental rut we’re in. And by massive I mean literally world changing, like a blue Arctic in September coupled with killer heat waves in the EU, US, China, and India plus a gigantic ice shelf in Antarctica breaking up just a few months later.

    When we reach the point where the average voter and consumer is very angry over the high cost of food and all these horrific impacts taking many lives, and they’re demanding answers from experts and action from governments, then we’ll be close to making progress. It’s never pretty when an addict hits bottom, and I suspect that the price of doing so will be awful before the whole world final gets the message. But we’re so far down this path already that I don’t see any way to get from where we are to where we need to be without going through some very nasty places along the way. More than ever, I really hope I’m wrong on this one…

  • Don’t apologise – no reason why people shouldn’t get to feeling sick over this stuff. It’s made me think though – not original thoughts perhaps, but: to get where you’re describing, we have to keep an eye on what we’re fighting. That is probably not, mainly, the denial swarm. It’s everyone around us, including ourselves, who are concerned but find ways to put it out of our minds. A phase transition in network connectivity can be swift, and I see this as the same thing: we have to work at those connections, and while we’re fighting the people making the most noise, we’re not making those connections.

    That manifests itself in weird ways. Seeing my brother this weekend, I did talk a bit about climate change, showed him the OECD report summary. What I *didn’t* do was grab him by the collar and shake him, or stand on a box and wail. Something in me doesn’t want to come across as some kind of evangelical – which is weird, isn’t it? I want to change people’s minds, but politely. Surely we’re past polite, aren’t we?

    Not to mention that I’ve just passed my driving test and have been commuting the 25 miles to work; that we’re talking about flying on holiday after a number of years avoiding it, because [insert mental fudge here but basically because we want to escape for a while].

    Where to start? Where to start with personal choices, with political choices? Where to put this energy? The worse it gets, the more it feels like we’re backsliding. No reason not to turn things around though – and I think that has to involve recognising that reaching the phase transition of awareness I mentioned is about making connections, not fighting the noise swarm (though that swarm is specifically attempting a denial of service attack on the whole network…)

  • Nice blog post from the Planet Under Pressure conference taking place in London at the moment. The bubble of hope nicely contrasted to the rest of the world going about its business.

  • Lou

    Dan:

    I’m beggin’ ya, please stop reading my mind. It’s getting just plain creepy. (But while you’re rummaging around in there, if you can remember the name of that funny kid I went to school with, I think it was 7th grade, who had long black hair and squinted a lot, drop me an e-mail. I’d like to try to look him up.)

    In all seriousness, this stark dichotomy between what we know intellectually and how we make countless consumption decisions throughout our days is something that I think about a lot, both in terms of people around me as well as how my wife and I live our lives. I also can’t help but think about how how certain trends or fads in consumption — gargantuan SUVs simply leap to mind as an example — inflict a cost on future generations often in exchange for a comparatively miniscule benefit.

    I hear things from people on “our side” that make me shake my head, like one friend who said that if she had a plug-in hybrid she’d surely forget to plug it in and therefore would drive almost entirely on gasoline. And then there are the hard core greenies who still(!!!) insist that “peak oil will be a good thing because it will force us to cut our emissions”. I had to squash that one in e-mail yet again just last night. I bitch a lot about the people who think that it’s enough to change their light bulbs, recycle their trash, and drive a Prius, and I find plenty of them on “our side” as well in the vast middle ground between the Sustainers and the Planet Killers.

    For me, much of it comes down to the relentless race of mindless consumption vs. informed, compassionate, and mindful consumption. As long as we live in a world where advertising and corporate influence is so pervasive and so effective, it’s going to be a really tough fight to get people to take a much broader and deeper view of their everyday actions.

    Thanks very much, Dan, for pointing me to that PUP blog entry. It should be required reading. Just like Eaarth, Merchants of Doubt, Storms of My Grandchildren, The Great Disruption, Limits to Growth, World on the Edge, the latest IPCC report (OK, maybe just select pieces of that one; no need to get crazy), and probably a dozen others whose titles I can’t read on my shelf from where I’m sitting. There I go again, being a rampant optimist…

  • adelady

    Yes, that Robert Palmer image did come to mind.

    “I bitch a lot about the people who think that it’s enough to change their light bulbs, recycle their trash, and drive a Prius, …” They’re simply out of date. If they’d started along this path 30 years ago – and installed White-House-mimicking solar the next time their water heater needed replacing – they would have steadily changed their attitudes and their habits without even realising it.

    The big problem we’ve now accumulated is that everything is going to have to happen at once. The best thing for modern economies is to make these changes desirable in the same way as connecting ‘the electric’ was for earlier generations. That change, in attitude, didn’t take very long. In some places the installation took longer, but onsite solar and local wind can make these changes quicker.

    Optimist – pessimist. I’m both. I very much fear that my not yet here grandchildren will live in a world of fear, violence and difficulty I’d rather not bequeath them. But if they and the following couple of generations really get their act together, we could come out the other side sadder but hopefully wiser. The intervening period will be worse than living through the wars of the 20th century, but it needn’t be that much worse.