Air Quality Matters – 2014 in review: Mobile sources – Part 3: Aviation

If California were its own country it’d be the world’s 12th largest greenhouse-gas-emitting country. This information was brought to bear in: “California’s plan to reduce greenhouse gases picking up steam?” (Mar. 23). Just so you know, I have read also where in terms of world-GHG-emissions output, the Golden State is ranked 15th according to one source and ranked 20th according to another. Whether 12th or 20th, GHG-emissions output in state is considerable.

The important thing to remember here is that California is mandated to reduce GHG emissions by approximately 31 million metric tons of carbon dioxide equivalent (MMTCO2e) by year 2020 from the level of what those emissions are currently or from approximately 458 MMTCO2e to 427 MMTCO2e, this while population grows at an average rate of 1.05 percent per annum, which, by 2020, is estimated to reach 40.4 million or 2.4 million more people than there are now. What this means is the state will have its work cut out to meet specified GHG targets.

By weight, transportation GHG accounts for 38 percent – the single largest GHG contributor in the state.

Besides GHG, there are other emissions of concern also. Their connection to aviation is what will be focused on in “Air Quality Matters – 2014 in review: Mobile sources – Part 3.”

Aviation – from: “For National Transportation Week, road, rail, air compared” (May 15):

320px-HH-65C_Dolphin[1]“One of the chief considerations when discussing transportation is the quantification of emitted pollutants; in other words, how much of what type of pollutant is being emitted one mode compared with others? For illustrative purposes, compared are airplane (A), car (C) and high-speed train (HST) for the following pollutants: Carbon dioxide (CO2), particulate matter (PM), sulphur dioxide (SO2), nitrogen oxides (NOx) and non-methane hydrocarbons (NMHC).

“The information below is referenced from ‘Figure 11 A modal comparison of air pollutant emissions.’2 Please keep in mind CO2 is measured in kilograms (kg) while all other pollutants are measured in grams (g). Please also note that the Frankfurt to Hamburg route in Germany was selected and the ‘Characteristics and components’ are expressed in ‘units per person travelling.’”

  • CO2 – 77.1 (A), 86.0 (C), 19.2 (HST)
  • PM – 2.1 (A), 21.2 (C), 1.0 (HST)
  • SO2 – 43.4 (A), 3.2 (C), 19.5 (HST)
  • NOx – 268.3 (A), 223 (C), 17.2 (HST)
  • NMHC – 20.8 (A), 18.3 (C), 1.1 (HST)

And, in terms of aggregate travel miles, meanwhile, in “State of state air: The worse for wear, but nothing that can’t be fixed” (Feb. 9), there is this:

“Currently there are six million annual flyers between San Francisco and Los Angeles.” That’s just between the state’s two largest metro regions. Imagine if what was accomplished by flying was restricted to driving. The distance in miles logged in cars would be a cumulative average 2.4 billion per year. That number of miles is determined based on a distance covered one way of 400 miles. Assuming most of the flying to be round-trip, the 2.4 billion yearly miles of travel then becomes a staggering 4.8 billion. Even though all that mileage is logged in flight, there is still the downside of polluted air.

“Responsible for 68.2 percent of the regional cancer risk was diesel particulate matter emissions, mainly from ‘diesel trucks and other diesel-powered vehicles and equipment,’ the SCAQMD [South Coast Air Quality Management District] found. Moreover, the air regulatory body found 90 percent of the risk to be from mobile sources; mobile sources that include cars, trucks, marine vessels (ships), railway locomotives, aircraft and equipment used in construction,” this from: “Further air quality gains noted by South Coast Air District in study” (Oct. 5).

On the other hand, the upside and this gets back to the GHG, is this: Through my research, what I found was that in the grand scheme of things transportation-wise, aviation’s GHG contribution is a comparatively small four percent.

Meanwhile, in aviation, cutting emissions isn’t the easiest. Although not a technical solution, what has proven effective at least in parts of Europe is supplanting mid-range flights (100 to 500 miles) with ground-based electric high-speed trains where operations between identical city pairs exists. This was discussed before in: “eMission control – Focus: Airways.”


On tap for Part 4 is maritime.

Image at top: U.S. Coast Guard

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