Aircraft Emissions and the Climate

I’ve been trying to find out something about aircraft emissions in the light of the Airport Authority Hong Kong (AAHK)’s consultation paper on the proposed third runway. According to Wikipedia, in 1992 CO2 emissions from aviation were estimated at 2% of global anthropogenic emissions. By 1999 the IPCC were claiming that the total impact of  aviation was 2-4 times the direct emissions of CO2, not including the effect of cirrus cloud enhancement from contrails. NASA’s Glenn Research Center currently states on its website that, “Aircraft produce up to 4 percent of the annual global CO2 emissions from fossil fuels near the Earth’s surface as well as at higher altitudes (25,000 to 50,000 feet)”. Meanwhile, in 2009, an analysis produced by Stanford University in Palo Alto maintained that commercial airline flights are responsible for 4-8% of surface global warming, and that contrails over the Arctic are responsible for no less than 15-20% of warming. Apparently, previous studies have only estimated the impacts of commercial aviation, whereas this study is the first to use actual emissions data produced between 2004-2006:

Finally, a recent study from the German Aerospace Centre states that although aircraft are responsible for 3% of annual CO2 emissions from all fossil fuels, their contrails, which form cirrus clouds, actually have a greater impact on the climate than their CO2 emissions.

I’m not able to assess the accuracy one way or another of these studies, but it seems as if the estimates of the impact that aircraft have upon the climate are steadily rising. Hardly surprising then that there is no mention of it in AAHK’s consultation paper!


About transitionsl

I've been an English teacher for the best part of 30 years, teaching in England, Tanzania, Brunei, Australia and Hong Kong. I've always been interested in nature and environmental issues, but it was the discovery of Peak Oil about five years ago that galvanised me into trying to help my local community to prepare for what will be a dramatically different world to the one many of us have been used to. I've been helping to run a transition group, following the guidelines created by Rob Hopkins's Transition Movement in the UK. This blog is an attempt to engage in discussion with a wider group of people in Hong Kong on the ways to transition from our current oil dependency to a state of fossil-free local resilience.
This entry was posted in Climate Chaos. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s