Could climate goals survive Heathrow's third runway?

If Britain is to meet its commitment to reducing emissions by 80% by 2050, can it afford to press ahead with Heathrow's proposed third runway? Supporters argue fiercely that it can - while opponents of airport expansion say stopping it is vital in the battle against climate change
Robin McKie, science editor
The Observer, Sunday 21 December 2008

At first glance, British American Tobacco, Friends Provident, Pirelli and the Trades Union Congress seem unlikely allies, straddling a vast political divide. Yet they are connected - along with 100 other UK companies and organisations - over a single controversial cause: the need for a third runway at Heathrow airport.
The group, which also includes Tate & Lyle, Hilton Hotels and the Scottish Chambers of Commerce, recently published a statement urging that the government approve the £12bn project, which would see a 2,200-metre runway as well as a sixth passenger terminal constructed on Heathrow's northern perimeter.
"Heathrow is vital for business," the group claimed. "It offers the direct connections which make our companies globally successful and which will be all the more important as India and China grow." The move allies British industry and trade unions with runway supporters that include the prime minister, the construction industry, engineers and aviation experts. All believe Heathrow's expansion is vital for Britain - but are opposed by the entire green movement, more than 100 backbench MPs, cabinet ministers that include energy and climate change secretary Ed Miliband and environment secretary Hilary Benn, and a great many scientists and analysts. They say the runway - which would see flights rise from 480,000 to 702,000 a year - would trigger a major expansion of the UK aviation industry and completely undermine Britain's commitment to reduce its greenhouse gas emissions by 80% by 2050.
Emissions from aircraft are our fastest-rising source of carbon dioxide and by 2050 could account for or almost all the nation's permitted carbon output. Cars, homes, factories and power plants would have to become carbon neutral just to accommodate the aviation industry's desire for unbridled expansion. A third runway is incompatible with the fight against climate change, the most pressing issue facing the nation, it is claimed.
But runway supporters claim that lighter materials, changes in aviation control procedures and more powerful jet engines will curtail fuel use and keep emissions in check. Aircraft will soon be carbon efficient and their increased use made acceptable. Thus technology will rescue the environment and keep British business in a competitive state.
But will it? That question goes right to the heart of the Heathrow debate. Can aircraft emissions be curtailed significantly over the next few decades and aviation continue to expand? Are our business leaders right to pin complete faith on the ability of innovative technologies to ensure aircraft no longer pollute the skies?
"I think a new runway will be crucial because it will allow aircraft to be taken out of the air," said Strathclyde University's Professor William Banks, president of the Institute of Mechanical Engineers. "At present, enormous amounts of fuel are wasted at Heathrow because it is running at maximum capacity.
"Every take-off and landing slot is precious, so planes wait, with their engines running, for long periods to get one. On Thursday, my plane waited out at the edge of a runway for 30 minutes before it got a chance to take off - and all the time it was burning fuel and emitting carbon. It's the same with landing. Aircraft stack for anything up to 30 minutes while waiting for a slot."
This dramatic use of fuel is necessary when you have a busy, cramped airport running on a very tight schedule. At present, Heathrow's two runways run at 99% capacity, with the result that even a relatively minor weather problems, mist or heavy rain, can cause serious disruption. Add a new runway and these problems will disappear, Banks argues. Planes will not have to keep their engines running constantly in a scrap to take off and land, a clear boost in the battle against global warming.
But the idea that a third, £12bn runway would be built purely to ease Heathrow's current congestion is remote, retort opponents, for it is unquestionably allied to aviation expansion in the UK. As runway supporters point out, Heathrow - Britain's only hub airport - now offers 50 fewer destinations than Amsterdam, 60 fewer than Paris and 100 fewer than Frankfurt. A new runway would let it add to its destination list: in other words, an expansion in UK aviation that would be crucial 'for continued job security and new employment", according to Steve Turner of the union, Unite.
But could this expansion be compatible with carbon emission controls? Banks believes so: "A new range of carbon-fibre reinforced plastics, very strong and of very low weight, are being developed which could cut aircraft weights significantly. This in turn would permit major reductions in the miles per gallon of kerosene of an aircraft and, of course, in its carbon emissions."
Aircraft such as the Airbus A340 are already constructed of 10% carbon composite material. The double-decker airbus A380, which is about to come into service, will be 30% composite, while the wide-bodied Airbus A350 and Boeing's 787 Dreamliner, which are set for flights around 2020, will be more than 50% composite.
Runway supporters also point out that changes in civil aviation procedures could bring major emission cuts. At present, planes fly into land on long, low trajectories that consume large amounts of fuel. If they were to plunge far more steeply, this would cut down on fuel use, it is argued. In addition, air traffic control measures could be changed so planes no longer fly on routes laid down by individual countries, forcing them to dog-leg over borders across Europe, wasting fuel use. Instead, routes would be rationalised so that planes flew in straight, energy-efficient lines.
But such ideas would require changes to international aviation regulations and could take decades to implement. Nevertheless, the suggestion reveals the kind of simple changes that could be introduced to make significant fuel and carbon emission cuts, it is argued.
Other changes in the pipeline are more radical, but are still likely to make a major impact. Manufacturers, such as Rolls-Royce, are developing generations of engines that will have greatly improved power-to-weight ratios and will be able to propel planes using far less fuel than at present. Thus, a package of lighter materials, improved aviation practices and more powerful engines should ensure that major cuts can be made in aircraft carbon emissions.
Nor are these the only measures being contemplated by the industry. Two other key changes could bring significant emission improvements, according to Charles Miller, of the aviation industry's Greener by Design group. "The first is biofuels, grown from algae, and the second is the use of blended-wing jets," he said. "Both have the capacity to make an enormous difference when it comes to carbon emissions."
Biofuels do not contain fossil carbon so don't add to the atmosphere's emissions inventory, while a blended-wing jet - an aircraft built as a giant, single wing so that the whole structure helps lift it off the ground - has such low air resistance that it burns a quarter less fuel than a conventional aircraft.
Its an impressive technological package, but opponents of runway three say it is very suspect. An example is provided by the blended-wing plane, said transport expert Professor Robert Noland, of Rutgers University, New Jersey.
"A blended-wing jet is an utterly new concept and has not been tested in any significant way," he said. "They are also associated with all sorts of problems, particularly concerned with safety. According to aviation regulations, you must be able to empty a plane of passengers in two minutes in an emergency. That can be done if you have lots of exits along a fuselage, but a blended-wing plane won't have one. How will you get people out?"
In addition, critics say that biofuels suffer from a major flaw. These are essentially alcohol, which burns at the wrong temperature for aircraft engines. Coal could be used to make kerosene, of course, but that would scarcely help with the issue of global warming.
Then there is the fact that carbon emissions have a disproportionate effect at high altitudes. Thanks to an effect known as "radiative forcing", carbon in the upper atmosphere produces 2.7 times more warming than emissions near the ground. That produces a major skewing of figures and makes it far less likely that the UK aviation industry, currently expanding at 5% a year, could avoid increasing, significantly, its carbon output over the decades. And that, in turn, has consequences.
"There is no way you can decarbonise the aviation industry," said Dr Sam Fankhauser, of the Grantham Research Institute on Climate Change in London. "That means if we are to make an overall 80% cut in emissions by 2050, some sectors of life will have to reduce their carbon output by 100% to accommodate aviation's increase.
"That will involve not just turning over our electricity generation to nuclear plants and wind and wave turbines, but making major changes in transport, land use, domestic heating and the insulation of homes across the country. And that assumes that all the improvements promised by the aviation industry, but which have yet to be developed and tested, work as promised.
"At present, people decide to fly off on holiday if they can afford the cost. Soon they will have to work out if they can afford the carbon as well."
History of air travel
• A British company 'Aircraft Transport and Travel' offered the world's first regular international flight, a London to Paris service, in 1919.
• In 2007, the number of passengers at UK airports rose to 315 million, compared with 4 million in 1954.
• The number of passenger kilometres flown by UK airlines increased from 80 billion in 1985 to 287 billion in 2005. Around 97% of the 2005 total involved international travel.
• The country with which the United Kingdom exchanges the most air traffic is Spain. There were 34 million passenger movements between the countries in 2005.
• Heathrow is the busiest airport in the UK, with 68 million passengers in 2005. Estimates from the Department for Transport suggest that the number of terminal passengers at UK airports will grow to 500 million by 2030.
Cars or planes?
• Driving a relatively fuel-efficient car generates fewer greenhouse-gas emissions per passenger mile than flying.
• Environmental website Grist.org calculates that driving 300 miles in an average-sized car generates some 105kg of carbon dioxide (CO2). Flying the same distance on a commercial jet, however, would produce some 182kg of CO2 per passenger.
• Long-haul flights are more efficient than short-haul flights as a high proportion of the energy is required to climb to cruising altitude. Flying the 2,708 miles from San Francisco to Boston would generate 1,300kg of CO2 per passenger, while driving would account for only 930kg per vehicle.
• In addition to CO2, planes emit other gases that contribute to global warming. Some estimates suggest that this means their overall greenhouse gas emissions are some 2.7 times higher than their carbon dioxide footprint.