Long ago I took an IATA survey to relieve the boredom of a long layover. Ever since, I’ve been on their mailing list, and received “invitations” to take additional surveys. Sometimes I do, out of curiosity – it’s fun to try to infer what they’re really after. The latest is a “Global Survey on Aviation and Environment” so I couldn’t resist. After a few introductory questions, we get to the meat:
1. Air transport contributes 8% to the global economy and supports employment for 32 million people. But, aviation is responsible for only 2% of global CO2 emissions.
Wow … an energy intensive sector that somehow manages to be less carbon intensive than the economy in general? Sounds too good to be true. Unfortunately, it is. The illusion of massive scale of the air transport sector is achieved by including indirect activity, i.e. taking credit for what other sectors produce when it might involve air transport. Federal cost-benefit accounting practices generally banish the use of such multiplier effects, with good reason. According to an ATAG report hosted by IATA, the indirect effects make up the bulk of activity claimed above. ATAG peels the onion for us:
So, direct air transport is closer to 1% of GDP. Comparing direct GDP of 1% to direct emissions of 2% no longer looks favorable, though – especially when you consider that air transport has other warming effects (contrails, non-CO2 GHG emissions) that might double or triple its climate impact. The IPCC Aviation and the Global Atmosphere report, for example, places aviation at about 2% of fossil fuel use, and about 4% of total radiative forcing. If IATA wants to count indirect GDP and employment, fine with me, but then they need to count indirect emissions on the same basis.
The next 10 questions point out various facts about the carbon intensity of aviation, with varying levels of relevance but at least no obvious factual distortions. Question 12 is a whopper though:
12. According to UN scientists, CO2 emissions from aviation will grow to only 3% by 2050.
Which UN scientists are these, exactly? 3% of what? Aviation and the Global Atmosphere paints a more varied picture: aviation ranges from under 2% to over 10% of fossil fuel consumption, and under 4% to over 14% of radiative forcing in 2050, depending on the demand scenario. IATA has apparently picked scenario Fa1, tied to IS92a, which happens to be at the low end of the range reported by the IPCC. That is, at least, a mainstream scenario. The big problem here is that expressing emissions as a share of global conceals the fact that the global baseline is greatly increased by 2050. As a result, the rise in Fa1 emissions from 2% to 3% of global emissions reflects an absolute increase in emissions of 116% by 2050. That emissions trajectory would seem to be at odds with questions 15 and 16,
15. Aviation’s aim is to have zero-carbon emission technology in 50 years.
16. The aviation industry has a great track record of technical achievement. Carbon neutral growth leading to a carbon-free future is entirely possible.
You’ll notice that these don’t sound much like questions. The real question in each case is actually, “A. What is your reaction to the statement above?” and “B. Does the statement above make you feel better about flying?” The menu of answers elicits whether I was aware of the factoid offered, and whether I find it striking and worth publicizing. Unfortunately, it doesn’t include the answers I’d offer on my own, like “I wasn’t born yesterday,” or “I don’t know, have you stopped beating your wife yet?”
The IATA’s sleight of hand pales in comparison to this slanted test, which starts with the disclaimer, “Caution: This section contains sound science, not media hype, and may therefore contain material not suitable for young people trying to get a good grade in political correctness.” They use every trick in the skeptic book to convey the appearance of science while obfuscating the issue.
- Question 1 implies that warming is perfectly normal, given that we’re in an interglacial, “If Global Warming stops, then you can start worrying! It means our warm interglacial phase is over and we may be heading into another Ice Age!” (Never mind that there’s no forcing, other than GHGs, to explain recent warming.)
- Question 3’s answer lists astronomical, atmospheric, and tectonic factors as the major drivers of warming – but the right answer to the “main cause of Global Warming” is only orbital and solar factors. (Again, it’s convenient to ignore the fact that these drivers operate on vastly different time scales.)
- Question 4 asserts that 95% of the greenhouse effect is water vapor. (Never mind that water vapor is a feedback not a forcing, and 95% overstates its effect.)
- Question 6 notes that CO2 is a tiny fraction of the atmosphere, implying that it must not matter much. (Now ignore physics and the tectonic and solar effects invoked in 3. Little things don’t matter – how about a nice glass of 0.1% cyanide?)
- Question 8 shows a schematic of 1000 years of global temperature and concludes that natural variations in temperature on ~500 year cycles are responsible. (Never mind that the “cycle” shown has a 900 year period, and that you can’t detect a 900 year cycle in 1000 years of data, or that this isn’t even data.)
- Question 10 asserts that satellites are the most accurate thermometers, and uses the satellite record to show that warming has stopped lately. (Ever heard of natural variation, or considered the implications of making inferences from short segments of noisy time series? Does this mean we’re headed for an ice age, as in question 1? This sort of rubbish seems to be in vogue lately.)
Surveys and quizzes used in this way are particularly insidious forms of debate. A quiz subjugates the taker to the maker, unless the taker is habitually skeptical of the content (an attitude schools work hard to suppress). A survey directs attention at the question, opening the door to insertion of suggestive, factually questionable framing that influences the taker unduly due to the emotional link established by seeking an opinion. This is not the way to think seriously about a problem.