Airline emissions are generated on the ground and at high altitude. Ground-level pollutants affect local air quality, while high-altitude emissions impact climate change. Two main greenhouse gases (GHG), carbon dioxide and water vapor, are emitted during flight. Pressure to regulate these and other GHGs is growing around the world, as demand for air travel is increasing at a rapid rate causing total emissions to rise.Global warming is the term that describes the general trend of warmer average temperatures and the projected increased warming trend that the earth is experiencing. The earth has only undergone minor average warming so far (1.3° Fahrenheit over the past century). However, scientific models predict that if warming continues at the current rate, temperatures could rise as much as 3° - 7°F during the 21st century. Such a rise would cause widespread environmental, economic, social and health problems. The term global warming, although still used widely, is now commonly replaced with the term "climate change." Climate change encompasses the changes that accompany global warming, like rising sea levels and alterations in wind patterns, rainfall amounts, and ocean circulation.

 

Carbon Dioxide (CO2) and other greenhouse gases exist naturally in our atmosphere and help to keep our earth warm enough to sustain life as we know it. The greenhouse effect refers to the way these gasses act like an atmospheric barrier, letting in some of the light and heat of the sun, but then creating enough of a barrier to trap the heat around the earth. Although these gases occur in nature and are not all caused by human activity, additional warming occurs when human activity creates greater concentrations of these gases in the atmosphere. 

Since climate change first gained prominence in the early 1990s, international governments have tried to come to an agreement on how best to deal with this global problem. Most of the industrialized countries in the world - except for the United States - are parties to the Kyoto Protocol. The Kyoto Protocol is an international treaty whose signatories agree to mandatory GHG emission reduction targets. The United States has several regional or state-based mandatory GHG reduction programs, but a sweeping national plan has been missing. The Obama administration has vowed to make climate change a priority, and there are currently several national initiatives in the planning stages, which primarily relate to power plant emissions. In addition, the United States has agreed to create and sign a binding international climate change agreement by 2015, to be in place by 2020.

Companies who want to be ready for climate regulation have several options. Any proactive company, certainly, will want to follow the status of pending legislation and regulation; this can be done by simply monitoring the websites of Congress and the Environmental Protection Agency. Proactive companies should also consider doing a GHG audit, so they know the size of their carbon footprint. Many companies, feeling certain that regulation will come sooner rather than later, are buying carbon offsets now because they are priced so low. When regulation is enacted, the price of offsets is likely to rise dramatically. Companies also buy offsets to improve their reputation as a "green" company. However, the use of offsets can be controversial, and if the offsets are shown to be less than effective in mitigating climate change, they can actually have a negative effect on a company's public relations.