Global Warming?

[Anton Gramscescu]

Anyone seen this paper and its attendant controversies?

To summarize, a paper in Nature by a leading climate change dude says that there could be a ten-year break in global warming due to some species of natural (i.e. non-man made) cooling tendencies which the earth may pass through in the next decade.

Some people seem to be saying this is paper is a "bad thing" because it will ease pressure on politicians.

Others are incredulous because, in the words of one climate change skeptic, "If global cooling over the next few decades is consistent with model predictions, then so too is pretty much anything and everything under the sun."

I know too close to zero about climate change to be able to assess this effectively, but on the face of it, the skeptics seem to have a bit of a point. But perhaps it's only rhetorical point, not a scientific one.

Can anyone shed some light here?

[Eggchaser]

Global Warming?

I believe the term is "pause" rather than break. But any excuse to stop us having to get off our arses and actually spend money or do anything.

[Ginger Yellow]

Global Warming?

"I know too close to zero about climate change to be able to assess this effectively, but on the face of it, the skeptics seem to have a bit of a point."

Why? Nothing about climate change science predicts an unbroken upward trend. The whole point of climate science is to tease out "long" term trends over multiple decades and centuries, not short range variation. And the same paper which predicts a plateau predicts accelerated warming after the plateau. Have a listen to the Nature podcast on the paper to get some more context and detail.

[San Bernardhinault]

Global Warming?

It's basically good news. If we are heading into a period with Atlantic and Pacific decadal oscillations moving to cool phases it gives us an extra decade of things not getting worse to sort out all the stuff that's going to screw us, like building a ton of half decent sea-defences and solar desalination plants in low-lying countries, and so on.

The sceptics, of course, don't have a point at all. For example, they cite 1996 as the warmest year on record, and say we've not had a warmer year since. This is true, but every year since 1996 has been, on average, warmer than every year prior to 1992. Fluctuations around the trend happen, some very hot periods will come in with El Nino events; some cooler ones around La Nina. Others around the North Atlantic oscillation, and some around the regular solar activity cycle.

None of this does anything to contradict the physics, which is utterly clear, that the emission spectrum of the earth peaks just around the peak absorption spectrum of carbon dioxide, in an area where there's a window in water's absorption spectrum. You don't need any empirical evidence to know that carbon dioxide is a greenhouse gas and increasing carbon dioxide will lead to an increase in temperatures.

But the observations do show an increase, and one that exceeds any of the variation ever observed for solar activity, say. And even if the decadal oscillations do lead to a stop in warming, we're still warmer than we've ever been in recorded memory (and lots longer than that, we surmise, from all the proxy data) - a few years of not getting warmer than the warmest we've ever been is not, exactly, a ringing claim for the skeptics.

It is true that the paper could get politicians to become more complacent. But I don't think it makes sense to argue against research being published because of political considerations. You just have to hope that if politicians accept this research then they accept all the other research that will say that when the decadal oscillations switch back, then we're going to get the climate warming on top of the decadal warming, and we'll get a doubled warming rate for the next ten years or so.

[Ginger Yellow]

Global Warming?

Has anyone argued against the publication of the research?

[Anton Gramscescu]

Global Warming?

From skimming, I got the impression that people had fretted about it but not argued against its publication.

[anton pulisov]

Global Warming?

Well said. (to chubby cyclist)

The long term predictions are still sound. The warming over the past decade has been well ahead of the long-term prediction. If things plateau for a bit then we'll still be bang on the predictions or perhaps even still slightly ahead of them.

It's like an economist predicting a 2% annual rise in the stock market over 10 years. If it goes down 1% in the second year, that doesn't mean that the economist was incorrect.

These oil lobby deliberately ignores the long term and concentrates on a year here and there. I've heard all sorts of shit bandied about, like how the Arctic Sea Ice extent was almost the same in 2000 as it was in 1990. This is technically correct, but to say such a thing is to deliberately ignore the long term trend and withhold the full truth. Look for yourself:

[Ginger Yellow]

Global Warming?

Incidentally, here's the key chart from the paper:



As you can see, even in the cooling scenario, warming catches up to the IPCC forecast by 2025. You can also see that the model predicted much lower temperatures than the observed data (red line) in recent years.

[anton pulisov]

Global Warming?

Yup, a picture is worth a thousand words.

And the skeptic who said "If global cooling over the next few decades is consistent with model predictions, then so too is pretty much anything and everything under the sun" is unable to read a graph properly.

[Ginger Yellow]

Global Warming?

I sincerely doubt he/she even looked at the graph.

[Moonlight Shadow]

Global Warming?

I've been reading a fair bit about this on the meteo-geek forum I check out regularly. There are some vociferous AGW deniers on it and some fence-sitters extraordinaire putting forward this so-called evidence. However, as someone succintly explained, we have entered what should be a cooling phase, the globe average temperature should be goind down if the natural cycle was intact. It's not, it has slowed down the warming but that's it. As Chubby said, it gives us a short respite to get our act together because the next time a strong El Nino occurs, it's going to hurt if we are out of that cooling phase and drive the point home rather mercilessly.

[anton pulisov]

Global Warming?

Meteorologists generally know as much about long-term climate change as a GP knows about heart surgery.

[Harbinger of Hope]

Global Warming?

What I always find mad about global warming, is the deeply ironic impact on Britain.

It is said, that when global warming has got to a ceratin point, that the warm gulf stream coming across the atlantic to Britain, from the gulf of mexico will stop. This will actually make Britain colder. A climate more like New Zealand, which is at a similar latitude but without the benefit of the gulf stream.

Great, i was looking forward to warmer summers and Britain's going to get sodding colder!!

[Anton Gramscescu]

Global Warming?

I'm not sure how much the accuracy of the models has changed over the years, but I would guess that the frustrating thing from an AGW point of view is that the models seem difficult to falsify because the margin of error on the predictions is so large. If the models say that temperatures will go up by 2 degrees over the next fifty years but there is a margin of error of 3 degrees (and I think as late as the previous IPCC report this was still the case), then pretty much no matter what happens, the climate change side can say "we were right!"

(To be clear, btw, I don't believe this is an argument for not doing anything, because the costs of doing *something* and finding out that climate change is true are, on a risk-adjusted basis, probably a lot smaller than doing nothing and finding out that climate change is even more severe than predicted.)

The analogy with long-term inflation predictions was a good one, btw, whoever brought it up.

And GY, I don't understand that last graph at all. What does the puprle line represent and why is it so short? Is the assumption that the purple line just rejoins the green line at the end?

[Ginger Yellow]

Global Warming?

As I understand it the purple line represents a forecast if CO2 emissions had stabilised at 2000 levels. It stops at 2010 because that's the interval of the forecast.

[Ginger Yellow]

Global Warming?

I might be wrong, but I think the margin of error in the IPCC report is almost all on the upside, as they derive it from assumptions about unmodelled feedback loops.