The global aviation industry pledged on Monday to halt the overall growth in aviation-related greenhouse gas emissions by 2020.
The International Air Transport Association, which represents more than 90 percent of international air traffic businesses, announced a target to level off aviation-related emissions and reach "carbon-neutral growth" through the use of improved fuel efficiency, biofuels, and carbon offsets. After achieving an annual emissions peak in 2020, the industry hopes to halve its total carbon emissions in the ensuing 30 years.
"Our industry has made significant commitments with concrete targets. The first is to improve fuel efficiency by 1.5 percent each year until 2020. But we recognize that improved fuel efficiency is not enough. Our emissions must stop growing," said Director General Giovanni Bisignani in a speech to 500 industry leaders at the IATA's general meeting in Kuala Lumpur. "Demand will continue to increase, but any expansion of our carbon footprint will be compensated."
Airlines have come under growing pressure to limit the greenhouse gas emissions that jet engines release into the upper atmosphere. Yet technological options to reduce emissions are largely unproven or are several years from application, according to a new U.S. government report, casting doubt on whether the industry can indeed shrink its carbon footprint as long as flights continue to increase.
The Intergovernmental Panel on Climate Change (IPCC) estimates that aviation accounts for about 3 percent of the warming caused by global greenhouse gas emissions.
The panel's 2007 assessment, however, was based mostly on 2000 air traffic statistics. Air traffic increased about 5 percent annually on average between 2000 and 2007, leading to a 38 percent increase in overall passenger traffic. Despite the global economic slowdown, international air traffic increased 3.4 percent in 2008 compared to the prior year, with the strongest growth among Latin American and Middle Eastern carriers.
The International Civil Aviation Organization, a United Nations-connected organization that sets flight standards, projected last week [PDF] that global air traffic, measured in paying-passenger kilometers, will decline 4 percent in 2009 but grow at a rate of 3.3 percent in 2010 and 5.5 percent in 2011.
Chinese and Indian travelers are projected to fly in growing numbers in the coming decade. Prior to the economic downturn, the Centre for Asia Pacific Aviation (CAPA) forecasted that India's domestic air traffic would increase 25 to 30 percent through 2010 and that 15 percent more Indians would travel internationally. In China, passenger traffic increased nearly 12 percent in 2007 and roughly 44 percent in 2006.
David Lee, director of the Centre for Air Transport and the Environment at Manchester Metropolitan University and a contributor to the 2007 IPCC report, announced last month a reassessment of international aviation's role in climate change. He estimates that aviation's contribution to atmospheric warming in 2005 was nearly 5 percent. The IPCC had projected that the sector would not contribute a 5-percent emissions share until at least 2050.
Lee warned that the full impact of aviation on climate change is still uncertain. Although high-altitude emissions tend to have larger effects on the climate, the scientific community is struggling to measure accurately the magnitude of this effect.
Given the rapid increase in air traffic, the industry's 2020 target is "admirable, but I think that it's nonsense," Lee said. "It's not possible except by massive use of biofuels and almost relying completely on carbon credits."
Industry leaders remain confident that emissions can be slowed, or at least offset, despite the growing contribution of aviation to climate change.
Bisignani said that the industry would shrink its carbon footprint - an estimated 666 million tons in 2008 - by 6.5 percent in 2009, a lower estimate than the previously projected 8 percent. The IATA predicts that the recession will contribute to 4.7 percent of the emissions reductions and that efficiency gains will account for the remaining 1.8 percent, he said.
"No other industry is as ambitious," Bisignani said. "No other industry is as united."
The IATA said that its members plan to replace 10 percent of aircraft jet fuel with "alternative fuels" by 2017. Since February 2008, four airlines have experimented with filling their planes with biofuel mixes of jatropha, algae, or coconut oil, often blended with kerosene. Bisignani said the use of biofuels such as jatropha could potentially reduce the industry's carbon footprint by 80 percent.
"It would be more environmentally beneficial to ‘fill up' the ground transportation sector first," he said.
A U.S. Government Accountability Office (GAO) report released on Monday surveyed several aviation experts and concluded that airlines could potentially reduce emissions through a variety of technological, operational, and alternative fuel options. For example, airlines could build fleets with more fuel-efficient engines; large engines could be replaced with several smaller options; and airframes could be built with lightweight material.
Advances with the most potential, however, are likely several years from availability, as well as costly, the GAO report said. Because most aircraft remain in service for 30 years or more, a rapid shift in fleet efficiency is also unlikely.
Rather than change out their aircraft, airlines could adjust operations, the report said. Air tankers could refuel aircraft mid-flight, or multiple aircraft could fly close together to reduce drag, for instance. But these options have fewer climate benefits than altering the planes themselves.
The GAO report concluded that government policies that place a price on carbon could lead to reduced aviation emissions. Otherwise, "incentives for industry to research and adopt low-emission technologies will be dependent to some extent on the level and stability of fuel prices."
With international aviation not included in the Kyoto Protocol, the current international climate change accord, European countries have recently passed measures to require sectoral emission reductions. The United Kingdom taxes the airline sector by as much as 2.7 billion pounds ($4.3 billion) annually, Bisignani said. And the European Union approved a directive earlier this year to include aviation emissions in its Emissions Trading Scheme, starting in 2012.
The world's 50 least-developed countries have proposed an aviation tax of roughly 1 percent on long-distance flights, as part of the ongoing negotiations for a new international climate change accord. The levy would raise $10 billion annually to help developing countries adapt to climate-related disasters, agricultural damages, and imperiled water supplies.
Bisignani said during his speech that the industry prefers a global approach to aviation that would cap the industry's emissions worldwide, rather than having each country set its own rules. "Airlines should get carbon credits for every cent they pay whether in taxes, charges, or emissions trading scheme payments," he said. "We should pay only once, not several times."
Kassie Siegel, director of the Center for Biological Diversity's Climate Law Center, has spearheaded a lawsuit that several environmental groups have brought against the U.S. government in an attempt to improve the fuel efficiency of airlines. She said that domestic measures, including fuel-efficiency standards or a carbon tax, should be considered in addition to global mechanisms.
"The level of emission reductions we need to avoid the catastrophic impacts of climate change is going to be a challenge.... So we need to use all the tools in the box," Siegel said. "Domestic tools are completely compatible with international tools."
With air travel on the rise, Siegel added that government policies will not be sufficient.
"We need people taking less short-haul flights. Changing those transportation patterns is part of the solution," she said. "We still have public awareness and political will [that are] far, far mismatched from the scientific urgency of the situation. I don't think we're going to have real solutions until we address that mismatch."
Image credit: Flickr/johndan, Creative Commons License.