Aviation has long been public enemy number one in the fight against climate change, and it's a title the industry has showed few signs of being able to shrug off.

Even the most optimistic observers accept that low or even zero-carbon flight is at best decades away, and while attempts to enhance fuel efficiency and cut carbon emissions by operating newer fleets or flying slower are welcome, they are never going to deliver the deep cuts climate scientists claim are required.

Faced with this reality, the aviation industry is seeking to combine investment in new flight technologies such as biofuels, with a focus on cutting emissions from the one area they can deliver deep short-term savings: airports.

At a number of flagship airports around the world, airport operators are seeking to reduce their environmental impact, whether by installing thousands of solar panels or using the grounds from your pre-flight latte to enhance the landscape.

New-build terminals today are often designed with sustainability in mind from the offset. Whilst Heathrow’s Terminal 5 got off to such a dismal start that the biggest boast they can make half a year in is that it's now "working," the building features a long queue of green features.

According to airport operator BAA, Terminal 5's water capture systems mean that 85 percent of the rainwater that hits Terminal 5 is utilized for non-potable purposes, such as flushing toilets and reducing demand on the main system by 70 percent. Similarly, 85 percent of the terminal's heat is supplied by the excess heat produced from the Heathrow heat and power station that is piped through an underground tunnel to the building, while 30,000 native woodland plants and 4,000 trees and shrubs are being planted around the terminal.

BAA also vows to help passengers reach the airport by more environmentally-friendly forms of transport and has provided free bicycle parking, of all things.

Let the Daylight In

However, it is in cutting their energy use that airport terminals can often deliver the deepest cuts in emissions.

Like the new terminal at Singapore Airport, Heathrow Terminal 5 features glazed walls and a roof designed to let in natural light and cut down on the use of artificial lighting. Meanwhile, Boston Logan Airport's new Terminal A has installed a heat-reflecting roof and windows and is the world’s first airport terminal to be LEED-certified by the U.S. Green Building Council. The terminal is estimated to have saved the operators almost $300,000 in electric bills and 1.7 million gallons of water a year through a raft of innovations, such as low-flow faucets and waterless urinals, self-dimming lights and storm water filtration systems.

Scorching hot days and ample snowfall are not extremes experienced often in the United Kingdom but transport ministers in Japan are hoping to keep airport visitors cool via condensation. They have announced plans to provide up to 30 percent of the cooling required at a major airport during the summer months using snow stockpiled in the winter. If all goes as planned, starting in 2010 snow will be used to chill the liquid used in the New Chitose Airport's cooling system, which could equate to carbon dioxide savings of up to 2,100 tonnes, according to government officials.

Solar-Powered Airports

One advantage airports have over other buildings looking to cut carbon emissions is that by definition, they tend to be surrounded by a lot of open space, giving them the potential to install relatively large-scale renewable energy plants.

For example, solar panels installed recently near the runways of Fresno Yosemite International Airport in California are expected to provide electricity to power 40 percent of the lighting, air-conditioning, controls and tower communications at the airport. The airport said the solar array will be 9.5 acres in size and is expected to save it $13 million over the next 20 years.

In the U.K., BAA has also said that thanks in part to a grant from Dept. for Environment, Food and Rural Affairs, the proposed terminal extension at Stansted airport will be "carbon neutral following the installation of a state-of-the-art biomass heating boiler, one of the biggest ever seen in commercial use in the U.K."

As well as helping to put a polish on airport's rather tarnished reputation, such initiatives will also help them comply with forthcoming carbon legislation, such as the U.K.'s climate change bill and its target to reduce emissions by 2050.

A spokesman for the U.K. Green Buildings Council said that while there is no specific environmental legislation targeting airport terminals, 18 percent of the U.K.'s total emissions come from energy used in non-domestic buildings and, just like other commercial properties, airports can expect to face increased legislative pressure to curb their carbon footprint.

Cutting the Waste, One Cup at a Time

As huge generators of waste, airports are also increasingly avid proponents of waste reduction initiatives.

One airport with an innovative approach to the problem of waste is Seattle-Tacoma International Airport, which has inked a deal with a local composting company to mix used coffee grounds from its 55 coffee outlets with lawn cuttings and yard waste from homes in the city. Completing the recycling loop, the airport then buys the resulting compost back for use in its landscaping and to help keep dust levels down between the runways.

Recycling bins have also become a common feature at airports around the world as operators seek to promote their green credentials to travelers and, while airports' environmental efforts may do little to offset the wider aviation industry's giant carbon footprint, they demonstrate that the sector is not without its green conscience.

This article originally appeared at BusinessGreen.com.