Even more great news!

Thanks to Quin for the pointer to this article by David Archer of RealClimate ("Irreversible Does Not Mean Unstoppable"):

Susan Solomon, ozone hole luminary and Nobel Prize winning chair of IPCC, and her colleagues, have just published a paper entitled “Irreversible climate change because of carbon dioxide emissions” in the Proceedings of the National Academy of Sciences. We at realclimate have been getting a lot of calls from journalists about this paper, and some of them seem to have gone all doomsday on us. [...] Let’s not confuse Irreversible with Unstoppable. One means no turning back, while the other means no slowing down. They are very different words. Despair not! [...]

Perhaps the despair we heard in our interviewers’ questions arose from the observation in the paper that the temperature will continue to rise, even if CO2 emissions are stopped today. But you have to remember that the climate changes so far, both observed and committed to, are minor compared with the business-as-usual forecast for the end of the century. It’s further emissions we need to worry about. Climate change is like a ratchet, which we wind up by releasing CO2. Once we turn the crank, there's no easy turning back to the natural climate. But we can still decide to stop turning the crank, and the sooner the better.

So the happy news here is that we're only somewhat screwed so far, and we still have some control over just how screwed we're going to be.  Are you feeling better now?

The article goes on at some length about the fact that what Solomon was talking about is just the "long tail" of global warming, which Archer says is old news.  However, here's what Solomon said:

"People have imagined that if we stopped emitting carbon dioxide that the climate would go back to normal in 100 years or 200 years. What we're showing here is that's not right. It's essentially an irreversible change that will last for more than a thousand years," Solomon says.

If the long tail is such old news, which people is Solomon talking about who are doing this imagining?  The hoi polloi?  Then it seems a bit odd to publish a scholarly study (pdf) about it in the Proceedings of the National Academy of Sciences—not exactly at the top of the average person's reading list.  Perhaps the only new information here is the determination that the long tail isn't just 100 or 200 years, but 1000?

I am not a scientician (or not a climate scientician, anyway) and I haven't waded through the entire paper or all of Archer's references, so I'm not qualified to resolve all the murkiness here.  When I originally read the NPR article about Solomon's work I suspected that "irreversible" might be carrying implications she hadn't intended, and so I can appreciate Archer's points.  But at the same time, there's clearly new information here or the NAS wouldn't be publishing this paper—and if it doesn't change the game at all, it's strange that Solomon would have put the information out there using such incendiary terms, both in the paper and in subsequent interviews.  Perhaps she's just painfully tone deaf to the way her words would likely be interpreted (as evidenced by her feeling that "if it's irreversible, to me it seems all the more reason you might want to do something about it").

In any case, Archer's right that it's not time to slit your wrists just yet.

Comments

[NomadUK]

So the happy news here is that we're only somewhat screwed so far, and we still have some control over just how screwed we're going to be. Are you feeling better now?

Not really, no, because we (or those of us in positions of power and influence, and the great unwashed who really can't be bothered to think about such things) are utter and complete shitheads, and all the evidence so far indicates that we (well, okay, they) will continue to go merrily along as we (they) are until utter and complete catastrophe strikes, and we all go to hell in a handcart.

I really think it's only a matter of time until that scene in Soylent Green in which Celia Lovsky gives Edward G Robinson the bad news:

Sol: It's horrible.
Exchange Leader: You must accept it.
Sol: I see the words. But I can't believe them.
Sol: Believe. The evidence is overwhelming. Simonson was a member of the board. He learned these facts. And they shook his sanity. The corporation knew he was not reliable anymore. They feared he might talk and so he was eliminated.
Sol: Then why are they doing this?
Exchange Leader: Because it's easier. I think "expedient" is the word.

[NomadUK]

Meh; fumblefingers:

Exchange Leader: Believe....

[SteveB]

"if it's irreversible, to me it seems all the more reason you might want to do something about it"

I think what this means is, "Since we're going to be stuck on whatever path we embark on for a very long time, it's really important we embark on the right path now.

[NomadUK]

Of course. John's point was that people hearing or reading that would very likely misinterpret it. And to top it all off, it has no emoticons.

[SteveB]

Yes, I agree that quote is confusing, given popular misconceptions about what "irreversible" means. I wonder if a car analogy would work? "Give me a car that can't go in reverse, and I can still choose how fast to go forward, whether to go left or right, whether to drive to the movies or over a cliff."

And doesn't the Second Law tell us that all real-world processes are "irreversible"? Another disconnect between scientific language and the language of the masses.

[John Caruso]

Coincidentally, I just watched Soylent Green against last night. It still feels like watching a future documentary—more than ever, actually, since it specifically invokes the greenhouse effect to explain the state of the world it depicts. And I'm with you on the prognosis.

Yes, Solomon's word choice was confusing, and for a climate scientist close to inexcusable. She should be aware that anyone following this issue closely knows that we're approaching the tipping point (or various tipping points)—beyond which nothing we do is going to constrain the natural processes we've set in motion. And her "irreversible" seemed to signal that she was saying we're now there. That's how I initially read it, and based on the "despair" Archer and others heard in interviewers' questions that's how it was taken by many others as well. I immediately thought, no, that can't be what she means or there'd be much more attention to this, but I didn't have time to investigate it further when I was writing that initial posting.

As James Hansen has said, "We have passed tipping points. We have not passed a point of no return. We can still roll things back, but it is going to require a quick turn in direction." Solomon's mistake was using language that implies that we have passed a point of no return—and that's a huge mistake in a political climate where there's tremendous resistance to the required change and people are looking for any excuse to avoid it.

So Archer was doing damage control, and I support that...but at the same time I feel like he oversold it a bit since he left the impression there's nothing new at all in these results.

[JMC]

Actually, scientists already have invented a simple method for reversing global warming, and we've made the investment to build tens of thousands of global-cooling devices that are ready to go at the push of a button! Plus, we have an enlightened foreign policy to ensure that such technology gets into the hands of as many people as possible. Therefore, global warming probably ranks as one of the least of our problems right now.

[John Caruso]

True—and there's no shortage of atolls out there to act as cooling stations (and if the residents don't like it they can go suck rocks).

Seriously though, the two biggest threats to humankind at the moment are global warming and nuclear weapons. But they're different kinds of threats: the first is incremental and its effects build only slowly, while the second is more or less binary—no effect at all, and then massive and instantaneous destruction (and the chances of any single nuclear attack resulting in more or the same are very high). So it's really just a matter of whether we manage to blow ourselves up before the more cataclysmic effects of altering our planetary environment start to kick in.

I think Robert Frost had something to say about all this.

[Quin]

Nothing intelligent to say at the moment, other than I always think it's pretty damn cool when one of my favorite bloggers, like, knows my name 'n stuff. At least temporarily.