Comments on: Single Best Reason Not to Panic About Climate

By: William Newman

William Newman — Tue, 15 Jan 2008 16:37:20 +0000

It's an interesting envelope-back analysis, and one that I'll probably be keeping in mind. But color me unimpressed by "One, there is no empirical evidence at all that positive feedbacks in climate dominate negative feedbacks."

We have abundant evidence that the climate spontaneously bounces around a lot. That's one of the reasons why periodically I look into this controversy, in fact. Every time I encounter an argument which doesn't adequately acknowledge the way that that confounds the interpretation of temperature trends in the last century, it becomes harder for me to avoid bouncing off the walls again. Now your analysis has me bouncing too by seemingly underappreciating the historical fluctuations, though in a somewhat subtler way.

To my (nonexpert) knowledge there is no known simple obvious back-of-the-envelope-suitable direct cause for the Ice Ages, Little and Big. (If you know one, it'd've helped if you'd mentioned it...) I've heard causes which sound possible. But as far as I know, it's not a settled matter that the Ice-Age-sized temperature fluctuations were simply a passive atmospheric response to large fluctuations which were created by positive feedback elsewhere (e.g., instabilities in the Sun causing large fluctuations in its output). The observed historical temperature fluctuations ought to be driven by positive feedback instabilities somewhere, and the atmosphere is on a very short list of obvious candidates for where.

Sure, when I look at a messy system which has been around long enough for transients to die, my first guess is that it's going to be basically stable, not brimming over with positive feedback. But that's just a first guess, weakly held. If I have a historical record of the system continuing to bounce all the hell over the place, my new first guess is that positive feedback ust often dominate negative feedback. Isn't that normal?

Pick any other system about which you don't know the details but do know that it booms and busts: stock prices, various kinds of animal populations, video footage of an unidentified missile's terminal guidance going wild by more-or-less oscillating around the ideal trajectory, whatever. Do you not consider the booms and busts to be strong evidence that the system has important modes in which positive feedback dominates negative feedback? Or do you have a pointer to research results showing decisively that the Ice Age fluctuations aren't evidence for atmospheric positive feedback because other fluctuations elsewhere (in solar output, whatever) are known to be large enough to explain the temperature fluctuations without positing atmospheric instabilities? If not, why aren't the Ice Ages strong suggestive evidence for quite a lot of positive feedback in the atmosphere? The atmosphere seems to be on a short list of obvious suspects, and I don't know of an alibi.

By: Steve

Steve — Thu, 15 Nov 2007 16:46:33 +0000

The above highlights the whole problem. The climate is a system with too much inherent variability to make accurate predictions given the data we have. This is something that the IPCC scientists are
entirely honest about and frustrated by if you read their own conclusions- not the UN's or Al Gore's
I think the key point in the article is about the positive(+)feedback. No one maintains that Co2 can directly affect temperatures in any meaningful way- it's all in the +feedback. the combined systems of- ice,algea,photosynthesis,air/water currents,clouds, etc etc are too complex by far to be accurately represented by pure mathematics- (the way you can predict a comet hitting jupiter for example) it requires a computer program. Now the problem is that even if you were to make the fantastic assumption that this program models the planet earth perfectly- there is no way to verify that it does- until it demonstrates reliable accuracy in it's predictions, this has not happened yet.

By: Scott

Scott — Sun, 11 Nov 2007 21:54:24 +0000

You raise some interesting arguments here. Can you cite any published scientific studies in support? The scientific research I've read explains that we will see an additional .5 degrees celsius of warming due to the radiative effect of our oceans. Once this is taken into account, the numbers in your future estimates change significantly. Also, the scientific studies I've read explain that the CO2 in our atmosphere is far from a saturation point in UV absorption.

Climate skeptics make a lot of interesting points, but without scientific research to support them, they're really just propaganda. Show me something to convince me that you're right... please!

By: Alan D. McIntire

Alan D. McIntire — Sat, 10 Nov 2007 16:17:09 +0000

In response to Newtronic: Yes, there would be a temperature lag. You notice one every day- the air isn’t warmest at noon; the highest temperatures are reached about 2 PM, or 1/12 of a 24 hour day later.
The coldest winter temperatures aren’t at the winter solstice; the coldest temperatures are in January, about 1/12 of a year later. Likewise, warming by the sun over the 20th century might be expected to have a
1/12 century lag in temperature changes. Here’s a link to a posting by
astrophysicist Nir Shaviv criticizing the Lockwood and Frohlich paper:

http://motls.blogspot.com/2007/07/nir-shaviv-why-is-lockwood-and-frohlich.html

You also might find Nir Shaviv’s website informative.

http://www.sciencebits.com/ice-ages

- A. McIntire

By: bob

bob — Fri, 09 Nov 2007 23:26:19 +0000

Adirian : are you for real? How exactly is you not burning fossil fuels, but instead getting a power company to do it for you, helping the environment? If you really cared about the environment you would (a) not be buying devices with lead, cadmium, etc (b) get off your butt and use a manual human powered mower.

By: Preston

Preston — Fri, 09 Nov 2007 18:42:44 +0000

I have heard several stories about high temperatures causing CO2 increases instead of CO2 increases leading high temperatures and I agree with them. This was a really well done observation. It is very condensed, so I appreciate you putting the link to the longer reviews! Still decreasing my own consumption of fossil fuels lead me to get a robotic lawn mower to take care of my yard rather than a traditional gas powered one. Bamabots.com has some reviews and good ecological reasons to choose robotic over gas powered mowers.

By: Adirian

Adirian — Thu, 08 Nov 2007 17:09:54 +0000

Newtronic – The atmosphere should heat up immediately, actually, which it has significantly been failing to do as expected. (Since the idea is that carbon dioxide in the atmosphere absorbs infrared radiation, getting hotter, and then reradiates that energy back downwards, as opposed to letting it pass through.) Surface air temperatures would suffer a lag time – which is why the troposphere is supposed to “lead” surface temperatures – but the current warming trends have been more heavily surface-side than they should have been. (No, the glitch that was corrected in satellite data does not eliminate the problem with the model, but merely reduces its scope.)

Lag for CO2 effects is a very interesting subject, because, historically, the lag has worked the other way around. Temperature shifts have led CO2 shifts – never the other way around.

More interestingly, and this is a point I haven’t heard addressed, high CO2 has never been sufficient in the past to keep temperature from declining – if it can’t even support temperatures, it’s highly unlikely it can increase them.

By: Newtronic

Newtronic — Thu, 08 Nov 2007 10:01:07 +0000

I haven't read your longer article and I also am ignorant on the IPCC's model. That being stated, it seems to me that there could also be a large Lag effect in your model. Meaning that you raise the CO2 today, and it might take 100 years for its effect to be fully felt. The ocean and the rest of the biosphere act as a giant heat sink that will take a while to heat up.

So as a thought experiment, if mankind all died off due to a plague and the CO2 stayed constant at 380 ppm wouldn't the temperature continue to rise for some period and then stabilize? Your climate sensitivity model doesn't seem to have any time lag in it.

Thanks for considering my naive question.