But ACI Europe's scheme did not set a deadline for airports to become carbon neutral, largely by cutting emissions from ground transport, boosting renewable energy and reducing the energy consumption of buildings.
The Airport Carbon Accreditation scheme covers about 26% of passenger traffic in Europe and includes some of Europe's biggest airports, including Frankfurt, Athens, Dublin, Amsterdam's Schiphol, Italy's Milan Malpensa and Orly in Paris.
London's Heathrow, whose owner BAA is struggling with a partial break-up, did not sign up.
ACI Europe's director-general Olivier Jankovec told Reuters the group's vast and diverse membership had made it impractical to set a deadline for airports to achieve carbon neutrality.
"If we'd looked for a date, we would never have got agreement," he said. "But we are engaging our members on the issue."
While green energy projects can ultimately pay for themselves, the scheme will require upfront investment during an unprecedented downturn in aviation.
ACI Europe predicted an 8% decline in passenger traffic in 2009, a 16% drop in freight, and financial losses among some of its members.
"The fact that we are doing this in the midst of the worst ever trading conditions speaks volumes about how serious we are about taking on the challenge of climate change," said Yiannis Paraschis, chief executive of Athens International Airport.
Cutting energy consumption has become a key priority in Europe as it seeks to lead the world towards a global deal to fight climate change at talks in Copenhagen in December.
Airport operations account for up to 5% of the emissions from aviation, which in turn represents just 2% of global greenhouse gases, said the group, which represents 440 European airports.
(EurActiv with Reuters.)