The Airlines Emissions Portal provides investors with an overview and links to useful resources related to the impact of the airlines industry on global warming and the practical steps which airlines, globally and regionally are taking or could take on this issue.

Overview

Airlines play an integral role in the modern world. Yet, there is rapidly growing concern over the impact that air travel has on the environment and in particular the climate. As a result, airlines are increasingly being pressured to curb emissions of greenhouse gases (GHGs), most notably CO₂.

Aviation as a sector is currently a relatively small emitter of GHGs compared to other industrial sectors.  In 1999, the United Nations (UN) backed Intergovernmental Panel on Climate Change (IPCC) estimated that in 1992, the industry accounted for about 2% of world-wide anthropogenic CO₂ emissions which amounted to about 13% of CO₂ emissions from all transport sources. Based on a range of scenarios of aircraft fuel use and projected growth rates, IPCC estimated that in 2050 potential increases in CO₂ emissions from aviation could be between 1.6 to 10 times the 1992 value.
 
In terms of radiative forcing (an indicator of global warming or cooling) IPCC have estimated that in 1992, aviation induced radiative forcing contributed about 3.5% of the total radiative forcing by all human activities. Based on their scenarios, IPCC projected that by 2050, radiative forcing as a result of aircraft emissions and excluding the effect of cirrus clouds could increase by a factor ranging between 2.6 to 11 times 1992 levels.

Global air travel is growing rapidly and combined with the unregulated nature of carbon emissions and increasing global importance of climate change, it is almost inevitable that the sector will be a target for both voluntary and regulatory controls. Indeed in Europe this issue is currently being widely debated throughout the industry. (The European Commission has announced a plan to include aviation in its existing emissions trading scheme (ETS) from 2011)