According to the Airport Council International-North America, U.S. airports employ nearly 1.2 million people and account for $1.1 trillion in economic activity – 7% of the total U.S. workforce and 8% of GDP. This major sector of the U.S. economy is also a significant contributor of greenhouse gases, and thus climate change. Aviation currently represents 2-3% of global greenhouse gas emissions, a figure that is increasing with the growth of this important sector.


In 2009, in response to the growing concern towards managing and mitigating climate change, the Airport Council International – Europe initiated the Airport Carbon Accreditation (ACA) program. Since then, the program has grown to cover every region of the globe and has won praise from the International Civil Aviation Organisation (ICAO), the United Nation Environment Panel (UNEP), and the European Union (EU). Today ACA has accredited more than 180 airports worldwide, including 21 in North America.


ACA-accredited airports can obtain four levels of accreditation, signifying their advancement and commitment in tracking, reporting, and mitigating their greenhouse gas emissions. Levels include the following:


1.  Simple monitoring and verified carbon footprint reporting

2.  Commitment to reducing greenhouse gases

3.  Expansion of emission reduction goals to include third parties

4.  Obtaining carbon neutrality by way of carbon offsets


You may be surprised to learn that the first (and currently only) U.S. airport to obtain the highest level – carbon neutrality – is Dallas Fort Worth International Airport in the great State of Texas. Not to worry though, California’s major airports are not far behind.


Getting started is easy, even for small airports. To apply for certification at one of the four levels of the program, airports must have their carbon footprints independently verified in accordance with ISO 14064 (Greenhouse Gas Accounting). The first step is for an airport to develop its greenhouse gas emission inventory, for which there are a variety of tools and resources available. For example, the Airport Council International offers a tool called the Airport Carbon and Emissions Reporting Tool (ACERT) – a self-contained Excel spreadsheet in which an airport operator can calculate its own inventory. The tool is available at no cost to airports and can be used by those without environmental expertise by inputting readily available operational data.


Once the carbon footprint is compiled, it must be verified by an approved ACA verifier, such as First Environment. Our greenhouse gas team includes five approved ACA verifiers located across the U.S., offering close proximity to most any major or regional airport in the U.S. and Canada. First Environment was also among the first firms accredited by the American National Standards Institute (ANSI) to the ISO 14065 standard for conducting greenhouse gas inventory verification services. In addition to the ACA initiative, we provide services under a variety of other programs, including the California Air Resources Board, American Climate Registry, Climate Action Reserve, Verified Carbon Standard, The Climate Registry, and Climate Bonds Standard (providing approved verification of green bonds).


Learn more about the ACA program on their website. For more information on how to develop your greenhouse gas inventory or have it verified, contact Jay Wintergreen at or 916.492.6080.