Graphing Out Loud: curves and lines

I love graphs – my eyes quickly glaze over at a table of numeric data, but a graph, used correctly, can quickly and easily tell the whole story.

‘Used correctly’ is the key phrase – for all their power, graphs are infamously easy to bungle, and when used incorrectly they can misinform – or lie outright.

I’m going to look at an example that touches on a few graphical and statistical concepts near and dear to my heart, as well as carbon geochemistry.

Fig. 1: An image from C3Headlines; the 3 C's are "Climate, Conservative, Consumer". Oh, and the article is titled "The Left/Liberal Bizarro, Anti-Science Hyperbole Continues". It sure would be tragic if they made obvious n00b mistakes after using such language. Click for link!

Coming from an article on the website C3Headlines, this image claims that carbon dioxide concentrations have ‘Linear, Not Exponential Growth’. thereby ‘expos[ing] the lunacy of typical left/liberal/progressive/Democrat anti-science’, The author has reached this conclusion by graphing January CO2 levels* and fitting a linear trendline to them.

Already this is a warning sign – the comparisons the author makes are entirely qualitative, apparently  based up on eyeballing the graph. However, trend lines are created by a statistical process called a linear regression, which comes with a caveat: it will fit a trend line to ANY data given to it, linear or nonlinear. Fortunately, there are also ways of evaluating how good a trend line is.

unknowns, uncertainties, and obsolesence

Antiscience campaigns often share the characteristic that they

A schematic of a climate model - By NOAA via WikiMedia Commons; click for sauce.

complain about the open questions, anomalies, and experimental limitations inscience. Scientists, on the other hand, work

hard to resolve these issues. Creationists complain about uncertainties on the chemical origins of life; biochemists generate and test hypotheses, developing useful technology and techniques in the process. (Bullard et al. 2006) A paper, championed by climate change skuptix, (eg, here) complains about the use of large flux corrections in climate models. (Soon et al. 2001) It was published a decade ago.

What was the state of computation back in 2001? There were no iPhones; cellphones still had hinges and were just starting to become controversial in schools. I didn’t see an iPod until late 2002, and for a long time it was just one person who had one*. We had just started trading AIM screen names instead of phone numbers. There was no Facebook, there was no Twitter, there was no YouTube. Xanga didn’t even appear on my radar until 2003. The Flash Revolution was in its infancy: StrongBad answered his first email in August 2001. It was, simply put, Peanut Butter Jelly Time.

Since then, while skuptix have done little more than whine, climatologists have been hard at work  improving climate models. It’s 2011 and climate models no longer use flux corrections. They still confirm the obvious: blankets are warm. More blankets are warmer.

* <3

~~~—~~~

Bullard, T., Freudenthal, J., Avagyan, S., & Kahr, B. (2007). Test of Cairns-Smith’s ‘crystals-as-genes’ hypothesis Faraday Discussions, 136 DOI: 10.1039/b616612c

Soon, W., Baliunas, S., Idso, S., Kondratyev, K., & Posmentier, E. (2001). Modeling climatic effects of anthropogenic carbon dioxide emissions: unknowns and uncertainties Climate Research, 18, 259-275 DOI: 10.3354/cr018259

John Everett, part VII: Help, help, I’m being repressed!

Supposedly posts with images get all the clix. So here is an image. Via PictureIsUnrelated; clix for sauces.

Part VI of John Everett’s testimony is a criticism of a geoengineering approach to ocean acidification. I agree with his conclusion (that adding alkaline calcium carbonate to the oceans is not a useful approach to ocean acidification) but nevertheless find this section to be problematic. I’ll return to it once I’ve finished with the rest of his testimony.

Part VII is a collection of research suggestions “that would go a long way toward establishing the likely effects of an increased CO2 world.” On the surface, it’s hard to take issue with his suggestions, but in the context of the rest of his testimony, they ring rather hollow.

For example, his first research suggestion is the development of

“a CO2/temperature timeline based on extant research on past climates, at least back to about 600 million years before the present. This effort would provide a critical review of candidate papers and unpublished work that goes well beyond a typical peer-reviewed journal publication, or prior summary reports of the IPCC.”

I think that it would be great to have a comprehensive review of the state of paleoclimatology and paleogeochemistry. But Dr. Everett ignores what we already know about those topics- so what good would such an effort be?

Suggestion #2: