Amyris Closes First Day of Trading at $16.50
BMW to Supply Saab with 1.6L Gasoline Engines

Cambridge-MIT Study Attributes ~8,000 Premature Deaths Per Year to Aircraft Cruise Emissions

Global plots for and LTO (0-1 km) and full flight (LTO + Cruise) operations: vertically summed average fuel burn (kg/s per 1° x 1°); ground-level BC perturbation (µg/m3); and ground-level total PM2.5 perturbation (µg/m3) attributable to aviation. Credit: ACS, Barrett et al. Click to enlarge.

A study by a team from the University of Cambridge (UK) and MIT attributes ~8,000 premature mortalities per year to aircraft cruise emissions. This represents ~80% of the total impact of aviation (where the total includes the effects of landing and takeoff emissions), and ~1% of air quality-related premature mortalities from all sources. The paper was published online 1 September in the ACS journal Environmental Science & Technology.

Aircraft emit nitrogen oxides (NOx) and sulfur oxides (SOx), which react with gases already existing in the atmosphere to form harmful fine particulate matter. This study research provides the first estimate of premature deaths attributable to aircraft emissions at cruise altitudes; current regulatory practice is to account only for landing and takeoff cycle (LTO) emissions—conventionally up to an altitude of 3000 ft or approximately 1 km.

Regulators have assumed that anything emitted above 3,000 feet would be deposited into a part of the atmosphere that has significantly smoother air, meaning pollutants wouldn’t be affected by turbulent air that could mix them toward the ground. Thus, even though 90% of aircraft fuel is burned at cruise altitudes, only those pollutants that are emitted during takeoff and landing are regulated by measuring emissions during tests of newly manufactured engines in simulated takeoff and landing conditions.

However, recent regional modeling work indicates that cruise emissions may contribute a significant fraction of aircraft-accountable ground-level pollutant concentrations on a regional scale.

We report simulation results indicating that aircraft cruise emissions are implicated in increased premature mortality on a hemispheric scale. Furthermore, meridional and zonal circulation patterns at cruise altitudes displace impacts from flight paths by several thousand kilometers. Our approach is to use a recent aircraft emissions inventory, a global chemistry-transport model, population density and disease statistics, and concentration-response functions derived from epidemiological studies to assess the impact of aircraft emissions globally on premature mortality. Parametric uncertainties in aircraft emissions and concentration-response functions are propagated throughout the analysis, along with estimates of modeling uncertainty.

—Barrett et al.

The researchers also note that the impact of landing and takeoff emissions is likely to be under-resolved. Secondary H2SO4-HNO3-NH3 aerosols are found to dominate mortality impacts.

Due to the altitude and region of the atmosphere at which aircraft emissions at cruise are deposited, the extent of transboundary air pollution is particularly strong. The authors describe how strong zonal westerly winds aloft, the mean meridional circulation around 30-60°N, interaction of aircraft-attributable aerosol precursors with background ammonia, and high population densities in combination give rise to an estimated 3,500 premature mortalities per year in China and India combined, despite their relatively small current share of aircraft emissions.

Subsidence of aviation-attributable aerosol and aerosol precursors occurs predominantly around the dry subtropical ridge, which results in reduced wet removal of aviation-attributable aerosol.

It is also found that aircraft NOx emissions serve to increase oxidation of non-aviation SO2, thereby further increasing the air quality impacts of aviation. We recommend that cruise emissions be explicitly considered in the development of policies, technologies and operational procedures designed to mitigate the air quality impacts of air transportation.

—Barrett et al.

The study was funded by the UK Research Councils with help from the US Department of Transportation.

Steve Lott, a spokesman for the International Air Transport Association, a trade group that represents 230 airlines, says that aviation is “a small part of a big problem,” particularly when compared to other transportation sources of emissions, such as those caused by shipping, which a 2007 study linked to 60,000 premature deaths per year.

Lourdes Maurice, the chief scientific and technical adviser for environment at the Federal Aviation Administration, says that if the agency can confirm the findings through additional research, then it will work with the Environmental Protection Agency and the International Civil Aviation Organization to consider appropriate regulatory action. The FAA will continue to fund research to address uncertainties highlighted by the work, she adds.

Lead author Steven Barrett from MIT notes that there are many uncertainties, including how accurately the model reflects how air travels vertically from high altitudes to low altitudes. To address this, he is collaborating with researchers at Harvard to study an isotope of the element beryllium that is produced naturally at high altitudes and attaches to atmospheric particles that eventually reach the ground through air or rain. Researchers have a general idea of how much beryllium is concentrated in the atmosphere, and Barrett and his colleagues are currently analyzing ground measurements of the element to quantify the extent to which the model “gets vertical transport right.”


  • Steven R. H. Barrett, Rex E. Britter and Ian A. Waitz (2010) Global Mortality Attributable to Aircraft Cruise Emissions. Environ. Sci. Technol., Article ASAP. doi: 10.1021/es101325r



These are probably the extremely low estimates. Reality or total well to air damages are probably at least 10 times higher.

The bad side of this is that we will have to live with it for decades to come because clean airplanes will not be sround for a long time.

The Goracle


"~8,000 Premature Deaths Per Year..."

And premature deaths, orders of magnitude greater, are caused by governments taking over health care. Sadly, some cheer about these premature deaths. Our prioritizes, and values, are incredibly poor.



Goracle, what conspicuous drivel. You are, however, to be applauded on your heroic but utterly irrelevant attempt to link aircraft aerosol emissions (principally in China and India) with US health care policy in that most obvious of places, a green car blog.

Firstly, unless I am much mistaken the US hasn't got a government health care system yet. We can determine this easily because most countries with such evil systems also have much better infant mortality and life expectancy figures than the US.

If your genuine concern is to prevent premature deaths, rather than mouthing off,again, about your precious liberties, you might consider first restraining, big tobacco, big food and big alcohol, all of which contribute very substantially to the tally of premature deaths. But can you stomach an attack on your God given right to scarf Big Macs?

The Goracle


Oh, dear... the "drivel" word has been thrown down. Now I'm convinced that England's government health care system does not kill more people than if it were run by people who cared. LOL!



Goracle, as usual you are 100% wrong. Unregulated Free enterprises, like tobacco, drugs and junk foods industries and many others, have been killing us at a much higher rate than airplanes for many decades.

Genetic defects are multiplying fast with all the inappropriate foods, drinks and air we have to use. More babies (like fishes) are born with genetic defects like autism, cancers, malformations etc and we refuse to see the real causes and act on it.

Cleaning up all what we have created will be costly.


It is true that the fast food industry contributes to the ill-health of any nation addicted to it. The solution we think is a combination of common sense regulation and EDUCATION. Scarfing cheeseburgers, sugar, high fat foods, clearly affects cholesterol levels and the incidence of heart disease.

It is fair to say that the food (fast and health) industry AND our health care industry should contribute to REEL education about the risks of food types with health. But do kids listen to educators about the risk of eating too much ice cream? It is then incumbent on parents to do their job of feeding children healthfully. Parents - not government need to take responsibility for their children.

Oh, and themselves. USA in this game are conspicuously FAT.


I direct your attention to the study regarding the location of particulates in the atmosphere, from NASA.

[sarc on]
From this, I adduce that the world governments should undertake to pave the Sahara desert. It would be more effective, and save millions of "premature deaths".

I also propose that everyone should be forbidden from going outside without being covered from head to toe to prevent exposure to UV radiation from the sun. It goes without saying that "sunbathing at the beach" should be banned. Think of the millions of "premature deaths" we could save.

The next undertaking for the government would be to drain the Oceans to a safer level. If the Oceans were only a safe 1 foot deep, why "drowning", certainly a fairly common "premature death" will all be averted. Think of the hundred of millions of "premature deaths" we would save.

Finally, I would ban the consumption of Bananas. No one would slip and fall on a banana peel, saving tens of thousands of "premature deaths".

[sarc off]


I'm surprized Goracle didn't use the catch phrase "Obamacare." Let's call the current system what it is - Nixoncare!


Cut the Goracle some slack. The number of deaths from biking far exceeds those from aircraft exhaust whether landing taking off or in cruise.

The comments to this entry are closed.