What Is Science?

When someone says, “Science teaches such and such,” he is using the word incorrectly. Science doesn’t teach anything; experience teaches it. If they say to you, “Science has shown such and such,” you might ask, “How does science show it? How did the scientists find out? How? What? Where?”

It should not be “science has shown” but “this experiment, this effect, has shown.” And you have as much right as anyone else, upon hearing about the experiments–but be patient and listen to all the evidence–to judge whether a sensible conclusion has been arrived at.

Richard Feynman in a speech to the National Science Teachers Association in 1966.

The Law of Demeter

Back in the 1980s, a group of programmers working on a project called the Demeter system realized that certain qualities in their object-oriented code led to the code being easier to maintain and change. Qualities such as low coupling; information hiding; localization of information, and narrow interfaces between objects. They asked themselves: “Is there a simple heuristic that humans or machines can apply to code to determine whether it has these positive qualities?”.

The answer they came up with came to be known as the “Law of Demeter”

I’ve heard about the Law of Demeter, but I didn’t know what it was. Avdi Grimm explains it nicely, with an example or two. Worth the read.

Oh, the law? Here ’tis:

For all classes C, and for all methods M attached to C, all objects to which M sends a message must be instances of classes associated with the following classes:

1. The argument classes of M (including C).
2. The instance variable classes of C.

(Objects created by M, or by functions or methods which M calls, and objects in global variables are considered as arguments of M.)

Agnotology, Agnoiology and Cognitronics

As Farhad Manjoo notes in True Enough: Learning to Live in a Post-Fact Society, if we argue about what a fact means, we’re having a debate. If we argue about what the facts are, it’s agnotological Armageddon, where reality dies screaming.

New words! Always nice to have some new words at hand.

I disagree with the Manjoo quote above. It is not always obvious what the facts are, and reasonable people can and do disagree about the fact-ness of a large number of claims about Objective Reality. So “if we argue about what the facts are,” it doesn’t seem to me to be all that horrible. For example, is it a fact that an increase in the cosmic ray flux results in an increase in cloud formation? If having a discussion about such a claim means “we argue about what the facts are,” well, bring on the agnotological Armageddon. All facts do not identify themselves by walking up and biting one’s rear. A large part of Everyday Science is a debate about “what the facts are.”

Once both sides agree that a claim is a fact, well, then “arguing about what the facts are” is silly. But getting to the point that we can have a debate about the meaning of facts? That’s nontrivial.

Are Chinese coal plants really cooling the planet?

Added: I’ve added a bit to the post, in italics, after some reflection and looking for satellite measurements of SO2. Quick take: we’ve only had satellite data sensitive enough to monitor fossil fuel SO2 contributions for 5 years or so. I haven’t found trend data yet, but I’ll keep looking.

A recent paper[0] from a team of statisticians at Boston University contains a claim that the lack of global warming during the first decade fo the 21st century is due to the cooling effect of sulfur emissions from Chinese coal plants. It is an interesting hypothesis, physically plausible, but I’m still digesting the paper. Here are a few musings after a read through.

Volcanoes can cause measurable global cooling due to SO2 emissions. However, a large volcanic eruption injects sulfur compounds high into the stratosphere where they are distributed widely across the global and linger for several months. As I understand it, coal-fired power plant stack emissions do not reach the stratosphere in any large amounts and are mostly confined to the troposphere. There are transport mechanisms for bosoting fossil fuel sulfer emissions into the stratosphere (e.g., thunderstorms) so the steady increase will add to the stratospheric SO2 load. Tropospheric sulfur is quickly washed out in the form of acid rain. Coal stack sulfur emissions are mostly a regional problem. Evidence for this is the fact that the US EPA shows a consistent drop in US sulfur dioxide measurements since around 1980. The Chinese coal emissions aren’t pushing up SO2 levels in America’s skies. The EPA measurements are made near the ground, so they can miss stratospheric concentrations. Still, the stratospheric component will contribute to near ground level measurements as it drifts down. It would be interesting to attempt to infer the global loading by looking at near ground measurements and perhaps acid rain data. Unless I’m missing something, if we don’t see elevated sulfur levels here, the cooling effect must be largely a regional, not global, effect just from physical considerations. Further, as the IPCC in earlier reports classed our understanding of the effect of sulfur compounds on climate as ‘poor.’ Simply because volcanic sulfur emissions in the stratosphere are effective at cooling the climate, it doesn’t follow that we understand tropospheric emissions enough to be sure the paper’s model is in fact correct.

So2

Speaking of models, as is so common in the climate papers, we have models used to predict both the SO2 cooling contribution, and more importantly, models that predict the warming from CO2 forcings, solar cycle forcings, and ENSO forcings. The authors conclude that their model shows the declining solar insolation of the Sun’s solar cycle, plus La Niña cooling, along with SO2 aerosols just balance out the CO2 warming effect from about 1998 to 2002 and have a small net cooling effect thereafter till 2008. Add it up and all the manmade warming and cooling effects just about cancel out, leading to no warming, and neatly explaining the lack of increasing global temps during the late Nineties and the Oughties (1998-2008). But there are other effects from burning coal besides higher sulfur emissions. As Chinese sulfur emissions rise, so do soot (black carbon) emissions, which tend to warm the air, and which the paper sort of glosses over by lumping the black carbon effects with stratospheric water vapor (which are deemed to be warming neutral, despite other research claims to the contrary). I don’t understand how the authors lump together stratospheric water vapor and tropospheric black carbon, nor how they simply dismiss their effects.

This is all a nice just-so story, and it may even be true. But I am skeptical of any climate result that comes strictly from models and not actual physical measurements that have real error bars. My main concern is that what the authors do is compare one set of models with another set of models. That is fine as far as it goes, but the map is not the territory. Models are simplifications. Models omit details, sometimes intentionally and sometimes unintentionally. And those details can be very important. In fact, if the authors are correct, the detail of SO2 emissions that was omitted from earlier climate model behaviors was just such an important detail! There is a 2005 paper that points out this very behavior, so perhaps we do have a ‘prediction’ which was not considered significant at that time. What other important details are missing from the models? Inquiring minds want to know!

I’m withholding judgement on this till others look to see how all this should play out. In particular, since I like to see physical predictions used to validate model conclusions, I’m looking for a regional climate signal due to the regional nature of the SO2 increase. In fact, if coal-fired power plant stack emissions are so effective at cooling, we should expect to see a warming effect in the US as our sulfur levels have dropped. But if anything, the US regional climate has been cooling faster than the global results. This seems counterintuitive, if the mechanism in the paper is indeed the correct explanation for global temps.

We should know more once real specialists have a chance to study the paper.

[0] I’ve used the WUWT link as the Proceedings of the National Academy of Sciences full text version is behind a paywall.

 

Maybe time to restart blogging at Ninth Law?

I’ve been following the Icelandic volcano situation over at I Can Be Terse, and I think I might have an occasional longer post that really should go here. So, I’m probably going to restart blogging here in the next week or so. The spiders in the corner are rejoicing.

Mýrdalsjökull – earthquakes during the last 48 hours

Mýrdalsjökull – earthquakes during the last 48 hours
(Preliminary results)

For those of you playing along at home, here’s the best place to keep track of the Mýrdalsjökull glacier’s earthquakes. The Katla volcano lies underneath the glacier. An earlier post described the glacial meltwater flood of 9 July.

ADDED: Whoopsie! If I don’t copy the images off the site, they expire. Rather than give a frozen picture, I’ll just remind everyone to go to the links above for updated info.

Small jokulhlaup at Katla in Iceland

Earlier today, Katla produced a small glacial flood (a jokulhlaup) that closed the Ring Road around Iceland. The scientists monitoring the events called it a very small event, possibly only a phreatic explosion under the ice that generated the meltwater. However, no one was hurt and there is little danger for tourists right now from the event.

More indications that Katla magma is on the move. You can find pics at DV (text in Icelandic).

Oh, and we also have sightings of cracks in the glacial ice. Still, no clear evidence of a small eruption, or clear indications of an impending major eruption. But I’ll keep an eye out for future developments.

Quote of the week.

When I asked Oxburgh if [Keith] Briffa [CRU academic] could reproduce his own results, he said in lots of cases he couldn’t,” Stringer told us. “That just isn’t science. It’s literature. If somebody can’t reproduce their own results, and nobody else can, then what is that work doing in the scientific journals?

Real Science isn’t a candidate for the Journal of Irreproducible Results.

An update on the Icelandic volcano at Katla

Volcanic activity at the Katla volcano site in Iceland in June 2011. Red were in the first ten days, green in the second, and blue in the final eleven days of the month. Katla lies under the glacier Myrdalsjokull. (info from Icelandic Met Office)

An update from the excellent Bittooth energy blog by Dr. Summers. Keep you eye on Iceland this fall, as the earlier post said, Eyjafjallajökull is normally a precursor to an eruption at Katla about 18 months later. Eyjafjallajökull blew in April 2010.

What’s Up Next? The GISP2 climate record

When I first started looking at GISP2 it seemed to me that there were several places in the record that looked very much like the sharp spike in temperature we’re experiencing now.  The obvious thing thing to do seems to be to overlay them for an easy comparison:


Here I’ve plotted the 400 years following each minimum in the record that leads to a sustained sharp rise.  There were 10 of them; the first five are plotted in cyan and the more recent 5 in blue.  You can see that in the latter part of the Holocene the traces settle down from the wilder swings of the earlier period.  Even so, every curve, even the early ones, seems to have an inflection — at least a change in slope — somewhere between 200 and 250 years after the minimum.

J. Storrs Hall is a very smart guy. He has taken a good look at the historical record, not simply computer model runs. Read his post over at WUWT where he compares the modern temperature record with the Greenland ice core reconstruction for the Holocene. The ice core reconstruction gives actual climate behavior. It isn’t a computer climate model run. You can see that Gaia’s behavior isn’t unprecedented; and I we can be sure the Neanderthals weren’t driving SUVs or burning coal for electric power.

Remember, extraordinary claims require extraordinary proof. I believe our climate has been warming since the end of the Little Ice Age. I’m less convinced that CO2 is the only, or even the major, driver of that warming. And as you can see above, the warming trend is not unprecedented.