Can aviation increase and carbon emissions fall at the same time?

Juliette Jowit explains the arguments for an against the expansion of Heathrow airport
Juliette Jowit
guardian.co.uk, Thursday 15 January 2009 10.04 GMT

The expansion of Heathrow airport has become one of the great environmental battlegrounds of our age in the UK.
On the one side, are environmentalists who claim aviation accounts for up to 13% of UK greenhouse gases and is the fastest growing source of emissions, and millions of residents who live under the flight paths fear a great increase in noise, local air pollution and congestion.
On the other side are supporters who claim the demonisation of flying is exaggerated because aviation makes up only 2% of global greenhouse gas pollution. They also claim that more direct flight paths and technological advances in biofuel engines will curb emissions rises even as the industry grows.
A more emotional argument underlies the statistics. This is between those who feel there is something deeply wasteful and unfair about rich people flying around the world when others face drowning in Bangladesh and mass extinctions are threatened; and those who believe aviation helps fuel the world economy, connects family and friends, and allows people to enjoy well-earned holidays or follow the human instinct to travel.
At one point the row became so vitriolic that Jonathon Porritt, the government's sustainability adviser and no fan of expanding aviation, was provoked into warning against a "new strain of deeply unattractive eco-puritanism about flying".
Separating the two sides is whether it is possible to fly more and meet ambitious pledges to cut greenhouse gases by 80% by 2050. The Tyndall Centre for Climate Change has calculated that under current plans, aviation would use up the entire UK carbon budget in 2050. The industry is more bullish about technological advances, and says a fixed cap on emissions set by the emissions trading scheme is a financial incentive to develop new technology and find ways to save fuel, or will pay for reductions in other companies if they fail.
Treading a cautious path between these two sides is the plausible scenario that emissions from flying will grow but not as dramatically as the number of flights, and later account for a significant proportion of the residual global carbon budget.
Adair Turner, chairman of the government's climate change committee, said: "It's possible for the world to cut greenhouse gases while still not cutting aviation by anything like as much, even increase aviation emissions." Although he has made it clear he was not supporting Heathrow's expansion.
"Society will have to make that prioritisation," said Porritt. "Aviation and chemical feed stocks will probably remain the two things society will want to reserve our hydrocarbon usage for."
The controversy over Heathrow runs deeper than the emissions figures. By giving the go-ahead to such a controversial climate project, the government would relinquish its authority to persuade the UK public or the world to cut their emissions, say critics.
"We get calls from journalists around the world and the signal we're sending is: Britons already fly more than anybody else in the world and we're going to fly a lot more because we think it's good for the economy," said Ben Stewart, a spokesman for Greenpeace, who also disputes the economic case for expansion. "How else do we say to countries that want to do x, y and z because it's good for their economy 'you can't do that' if we're going to do it."
Most foreign governments are clamouring to build their own airports – along with coal plants and motorways – so might accept this as "realpolitik", said Porritt. But simply by making it such a controversy, critics could make their argument self-fulfilling.
On the expected assent to the runway today, he said: "I guess they [the UK government] are hoping that their reputation will survive because of the fact of the [recent] Climate Change Act and they'll be able to bat away any suggestions about inconsistency, cant [and] blatant hypocrisy," said Porritt.
"From my perspective I just think it's inconceivable you can hold those two things in your mind at the same time: [that] you're really going flat out for rapid decarbonisation and perfectly reconciled to expansion of aviation."