The skies above Stockholm airport are grey with snow, but inside the B737-700 flight simulator conditions are fine. Scandinavian Airlines (SAS) has joined forces with the Oxford Aviation Academy (OAA) to develop an “eco-pilot” training scheme promoting fuel-saving techniques and environmental awareness, and I am here to try it out.

On this real-time flight from Gothenburg to Copenhagen, our captain, Mathias, is demonstrating how much fuel can be saved by taxiing on the ground with one engine, accelerating and ascending steeper and faster, avoiding flying at maximum speeds to make up time, and extending the flaps on descent at the last possible moment.

Compared with the same route flown “normally”, we make a fuel saving of 22 per cent. Per de la Motte, director of training and head of the Nordic region for OAA, says: “This is not a realistic saving – it is what we could achieve in an ideal world. But even if we could save 5 per cent of fuel on each flight, that would be great. We need to get this into the spines of pilots so they think and breathe green flying.”

About 400km away at Helsinki-Vantaa airport, Finland’s flag carrier Finnair is also demonstrating that green issues are close to its heart. As at Stockholm, pilots flying into Helsinki benefit from uncongested airspace and three runways, allowing planes to make continuous descent approaches – spend half an hour circling London Heathrow and you can imagine how much fuel can be wasted waiting to land.

Although Finnair has been making these “green approaches” for years, it is also making headway in improving the footprint of its fleet – it is replacing its aged MD-11s with more efficient A330s and A340s, has installed lighter seats on its European Airbuses as part of its “weight watchers programme”, and is washing the engines more often, which reduces CO2 emissions by up to 2 per cent per flight.

The airline is also promoting its hub as a green-friendly access point into Asia from Europe. Flying over the North Pole is geographically the quickest route, and Kati Ihamaki, vice-president of sustainable development for Finnair, claims: “Non-direct flights such as New York to Delhi via Helsinki are often more efficient. With direct flights you have to fill the plane with more fuel but the extra weight means it burns more and, consequently, creates more emissions in the first two hours of flying.”

These days, most carriers have an environmental policy of some kind, but some airlines are particularly keen to shout about what they are doing. It’s an important issue for the industry – aviation is responsible for 2-3 per cent of greenhouse emissions globally, but if left unchecked, some commentators believe it could leap to 50 per cent by 2050.

One of the next initiatives to curb the negative impact of flying is the EU Emission Trading Scheme (ETS) in 2012. This will require all airlines to monitor and report their CO2 emissions, and if they go over the cap set, they will have to purchase extra carbon credit allowances from those who pollute less. But as there will be a finite number of allowances, the amount of CO2 emitted will be limited. (Visit for a special report on the ETS.)

The International Air Transport Association (IATA) has also proposed a number of measures for airlines to work towards. These include cutting CO2 emissions by 1.5 per cent over the next ten years, and by 50 per cent (compared with 2005 levels) by 2050, as well as making all industry growth carbon-neutral by 2020.

So what are the airlines doing to achieve this? Mike Carrivick, chief executive of BAR UK (Board of Airline Representatives), says: “Some carriers are looking at biofuels that will not just replace kerosene but will actually lead to fewer emissions. They also want to derive the fuel from anything that does not take up water resources, such as algae. But the research and development takes time if you want safe results – one of the hardest things is testing for the correct freezing point, bearing in mind that planes are flying at higher than 30,000ft.”

Air New Zealand, Qatar Airways and KLM are leading the way. The Kiwi carrier ran a test flight just over a year ago partially powered by vegetable oil, and in October, Qatar completed what it claimed to be the world’s first commercial passenger flight powered by a fuel made from natural gas. The flight, from London Gatwick to Doha, was operated by an A340-600 using GTL kerosene, a fuel the state of Qatar is set to produce commercially from 2012. The following month, KLM flew a B747 partially powered by biokerosene.

By 2017, IATA hopes that 10 per cent of airline fuel globally will be renewable. Lars Andersen, director of crisis communication, environment and public affairs for SAS, says: “In the Scandinavian market, we think that 10 per cent of our fuel will be renewable in the next 11 years, so we have a more moderate target but one we feel is realistic.” Virgin boss Richard Branson, Japan Airlines (JAL) and BA are also supporting research into alternative fuels. Jonathon Counsell, head of environment for British Airways, says: “Unlike technology, which generally takes 15-20 years to roll out, as soon as biofuels are available they are ready to go.”

Another way to tackle fuel efficiency is reducing weight, and many carriers are taking steps to shed some kilos. Every year at the Business Traveller Cellars in the Sky wine awards, the judges come across a few bottles made from significantly thicker, heavier glass, and lament the unnecessary weight this adds to an aircraft. One carrier that has taken steps to combat this is JAL, which now serves economy passengers wine in PET plastic bottles that weigh one seventh the amount of glass ones.

In December, Gulf Air announced measures it would be taking to cut its CO2 by 33,000 tonnes a year – these included reducing the amount of drinking water on board by 25 per cent and combining its two in-flight magazines, printing on lighter paper and carrying fewer copies. KLM, too, is on a diet. Inka Pieter, its director of corporate social responsibility and environmental strategy, says: “We are trying to reduce our weight and fuel by 1 per cent a year by providing lighter blankets and taking as few newspapers as possible with us.”

German carrier Lufthansa, which claims to have achieved a 30 per cent reduction in fuel consumption in the past ten to 15 years, has been developing lighter seats, as has Swiss, while BA has modified its products. Counsell says: “There used to be a footrest on every World Traveller Plus seat but passengers said they didn’t need them, so we took them out. They are about 1.5kg each so, depending on the configuration, you could be saving 100-200kg per aircraft.”

The route a plane takes can also have a real impact, and talking to representatives from a cross-section of European airlines reveals that they all seem to agree on fighting for a Single European Sky. Carrivick of BAR UK explains: “In the US, there are about six airspace control regions and that’s an efficient way of doing it. In Europe, there are about 35 control centres that don’t link together, and there’s lots of inefficient use of airspace that leads to delays and longer routings. So we want airspace management in Europe to change.”

Karlheinz Haag, head of group environmental concepts at Lufthansa, adds: “We estimate that if we had a single European sky and could avoid holding patterns, we could save about 500,000 litres of fuel a day.”

Counsell says BA is looking at ways to fly more direct routes. “We have achieved some success, such as our routes to Brazil and over Kazakhstan, and we are in constant negotiations with air traffic control authorities around the world,” he says.

So which airlines are the greenest? Controversially, a study by travel comparison search engine

suggests that low-cost carriers such as Ryanair, Easyjet and Flybe have a lower carbon footprint. When talking about efficiency in terms of the amount of CO2 emitted per passenger, this makes sense. Budget airlines fit more seats on to their aircraft – for example, an Easyjet A320 has 174 seats whereas one in BA’s fleet might have 108 – and tend to fill more seats because of their low prices.

They also tend to have younger, more fuel-efficient planes – Easyjet’s fleet is 3.5 years old on average, while Flybe has invested heavily in its new fleet of Bombardier Q400s and Embraer 195s, two of the most green-friendly types of aircraft. In addition, they often fly to smaller, secondary airports that are not so congested, so less fuel is wasted queuing to land.

While the maths may add up, others argue budget airlines are not green at all because the low price of tickets attracts people to fly who may not otherwise, and encourages the rest of us to take to the skies more often. According to Tony Grayling, head of climate change for the Environment Agency, this isn’t the problem. “At the moment, climate change doesn’t require us to reduce the amount of flying we are doing, but to moderate the rate at which aviation emissions are growing,” he says.

So are the airlines doing enough? According to Andy Harrison, chief executive of Easyjet, it is the manufacturers who will make the real difference. “Technology in aviation is very powerful,” he says. “The B787 Dreamliner will be the biggest change to commercial aviation since the jet engine. The design, with a body made from a single carbon-fibre shell, offers massive weight and fuel savings.”

However, Harrison believes the authorities need to set minimum standards for emissions if a 50 per cent reduction in C02 by 2050 is to be met. He argues that from 2015, new aircraft should have a 40 per cent improvement on emissions. And given that emerging superpowers (and big polluters) such as China buy mostly Airbus and Boeing planes, the only way to deliver environmental efficiency around the world is to set minimum standards for all. “We need to control emissions at the source,” he says.

In the meantime, we can all do our bit by offsetting our CO2 – visit for tips on lowering your footprint and a list of government-approved schemes.