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Aviation Global Warming Pollution Will Rise Without New Action: Study Details

Jake Schmidt

Posted March 5, 2013

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Aviation’s contribution to climate change is projected to almost triple by 2050 without any new action. Even with all the expected measures in the aviation sector, aviation’s contribution is still expected to grow and fail to meet the industry’s own stated emissions target, according to a new study. With international aviation negotiations gaining new momentum, now is the time for the U.S., China, India, Europe, and South Africa to secure a global agreement that includes an emissions trading program. The deep cuts from the aviation sector necessary to address climate change won’t be within reach without such a policy.

The new study—Bridging the aviation CO2 emissions gap: why emissions trading is needed—from leading aviation researchers at Manchester Metropolitan University is the most comprehensive study looking how the aviation sector can reduce its contribution to climate change. The researchers evaluated the projected rise in aviation’s climate pollution and the expected emissions reductions from the various measures that the airlines and countries are pursuing – operational (e.g., improved air traffic), technical (e.g., more efficient new planes and minor upgrades to the existing fleet), and biofuels (e.g., from algae). The researchers then analyzed what would be achieved if the existing regional emissions trading program in Europe was extended through 2050. Lastly, they analyzed how close those measures would get the industry to the various stated pollution targets for the aviation, including the industry’s own stated target of “no net emissions growth after 2020” and the goal proposed by the U.S., Mexico, and Canada to “hold net emissions to 2005 levels by 2020”.

This new study has some interesting findings:

Operational and technical measures won’t achieve enough. The aviation industry has improved its efficiency by 1.3 percent per year historically and most estimates assume that it will achieve about that level of efficiency improvement in the future as the airlines turn over their old fleet and replace it with newer, more efficient planes.* While these measures will slow the projected growth in pollution, the most aggressive operational and technical measures are predicted to still result in aviation’s pollution increasing by 217 percent above 2006 levels in 2050.** This would put the industry well above its “no net emissions growth after 2020” target, and well above the even deeper cuts that the U.S. and others proposed.

Even with aggressive introduction of biofuels, aviation’s pollution will increase significantly. A detailed assessment of the potential for aviation biofuels found that these fuels could account for 10% of aviation’s fuel in a “likely” scenario and 30% under the most aggressive penetration by 2050. So even with the most aggressive biofuel penetration combined with the technical and operational measures, aviation’s pollution would still be almost 170 percent above 2006 levels in 2050. Once again this would put the industry well above any semblance of a reasonable climate target for the industry.  

Continuation of the European program combined with other measures makes the biggest dent. The European Union introduced an emissions trading system that would require that all flights using European airports control their carbon pollution. While enforcement of the law was put on hold through 2013, the law will go back into effect in 2014 if a strong international agreement isn’t secured. The Manchester University researchers considered a scenario where the European program continued and the other technical, operational, and biofuels measures were implemented. This achieved the greatest reductions in carbon pollution, yet aviation’s pollution still more than doubling its 2006 level and still above reasonable target levels for the industry (see figure).Aviation Emissions Growth with Measures.PNG

This shows clearly that efforts to undermine the European program will lead to more climate change as the greatest reductions are achieved by a program that combines the European emissions trading program with other measures. But it also signals that…

We can’t achieve what is necessary to address aviation’s climate pollution without a global emissions trading system. The results show that the we can’t get to the industry’s own stated target, or the even deeper targets necessary to address climate change, without a global emissions trading system (see figure).

It is time for leadership from the U.S., China, India, and South Africa to secure a global agreement. Will they help solve global warming or will they throw up roadblocks to controlling the growing climate pollution from aviation? 


* Note the study assumes that under business as usual conditions the industry would achieve a one percent efficiency improvement from 2010 onwards.

** The most aggressive scenario assumes that CNS/ATM initiatives are implemented and the aviation industry improves its fleet efficiency by 1.5% through 2036.

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Michael BerndtsonMar 6 2013 10:03 AM

I have a question. I raised it in the comment section of Dot Earth - the topic was Middle East soil/groundwater drying - but the question arose because a situation was brought to light by a soil scientist in Israel - and I made a jump from soil to sky. Anyway, my question is in regards to the effects of jet contrails and climate change, with respect to the ever increasing jet plane travel with Asia coming online for freight transport and passenger miles.

Since I'm too lazy to re-write the question, I'll just cut and past from Dot Earth [my edits to my dyslexia or similar problem is in brackets]:

"I thought about climate change upon reading this post. I remembered a NOVA program on jet plane contrails and the almost elimination of them for several days after 9/11/2001 - due to a US enforced grounding of flights. In the program, a soil scientist from Israel and a professor from UW Whitewater were interviewed and mentioned noticing a significant [INCREASE] reduction in solar radiation reaching the surface during this period of time - as well as an increase in surface temperature and [INCREASE] decrease in water evaporation (via pan measurements). They both cited the issue relating to contrail reduction.

So anyway, I looked up in Google Labs - Public Data yesterday and found out that the worlds air freight and passenger miles flown have increased beyond a geometric rate, starting around the mid 1990s. That is about the time that Asia had come online. Therefore, I'm assuming that over the past 16 years or so the extent of our atmosphere impacted by the affects of contrails has greatly increased - and a corresponding reduction in solar radiation onto the earth's surface is possible.

So my question is this... is the proliferation of jet travel over the past 16 years a possible explanation for the slight decrease in the rate of temperature rise over this period?

NO I'm not suggesting scrambling every jet plane for climate change mitigation - since CO2 based warming is becoming evermore important as a mechanism with increasing concentration."

Simply put - is NRDC aware or up-to-speed on the effects of jet plane contrails on climate change - or has this issue been put to rest?

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