骑乐无穷
上帝不响。如歌单车。Tune Your Ride. Every Day. Amen.
"Bicycling: Big Brainpower Booster."
| Don Butler |
| The Ottawa Citizen |
Sunday, July 29, 2007
Despite all the airport lineups and security checks and delays and hassles, we still love airplanes. In the midst of a dispiriting Canadian winter, they whisk us to a Caribbean beach in less time than it takes to drive to Toronto. Thanks to airplanes, we can enjoy April in Paris, theatre in London, the Acropolis in Athens. The more adventurous can trek in Nepal, snorkel in Phuket or gambol in the Galapagos.
Airplanes connect us with far-flung family and let us sleep in our own beds after business meetings 1,000 kilometres from home. Better yet, the clever people who run airlines have found ways to make air travel ever cheaper in relative terms, so what was once a preserve of the rich is now accessible to almost anyone with an income. Some airlines have even offered free seats.
We show our gratitude by flying in ever-increasing numbers. In 2005, nearly 94 million passengers arrived at or took off from Canadian airports -- six million more than in 2004. Worldwide, more than two billion passengers fly on scheduled airlines annually, and hundreds of millions more on charter carriers. This May, global take-offs exceeded 2.5 million for the first time. Oh yes, we love planes.
But there's a shadow on our love affair, an inconvenient truth that some say could bring this golden age of aviation back down to earth.
It's serious enough, warns David Hodgkinson, an aviation consultant based in Australia, that "people could come to regard air travel in some respects in the way that they regard smoking, as an undesirable activity."
It may be be happening already. Last year, the Bishop of London told clergymen they should preach that flying on a holiday is a "symptom of sin." The founders of the Rough Guides and Lonely Planet travel books are urging travellers to "fly less and stay longer." And Edward Hasbrouck, author of the Practical Nomad travel book series, predicts the era of accessible world travel "is not going to last more than another generation or two at most."
What has them spooked is climate change. Or more precisely, aviation's escalating contribution to it.
ATTENTION ALL PASSENGERS
While scientific understanding of aviation's impact on climate is incomplete, the studies done to date suggest there is cause for concern.
At present, aviation's contribution to climate change is not especially large. In 1999, the International Panel on Climate Change put aviation's share of human-generated global carbon dioxide emissions at two per cent in 1992.
But most agree this understates its impact. Air travel has grown significantly since 1992, and the IPCC estimate doesn't include other aviation emissions, including nitrogen oxides, sulphur oxides, water vapour and soot, or the warming effect of airplane contrails.
Nor does it account for the fact airplanes release emissions into the thin air of the troposphere or upper stratosphere. Together, these factors are thought to make the climate impact of aviation two to four times greater than its CO2 emissions alone.
One thing is clear: aviation emissions have been rising rapidly. A 2006 report by Britain's Tyndall Centre for Climate Change Research found that emissions from international shipping remained fairly stable between 1990 and 2000, but those from international aviation soared by 48 per cent.
During that same period, carbon dioxide emissions from British aviation doubled, while aviation emissions in the European Union have risen by 87 per cent since 1990. In Canada, emissions from domestic aviation rose 19.1 per cent between 2003 and 2005 alone, second only to the chemical industry during that period.
This has happened despite solid improvements in fuel efficiency -- 20 per cent in the past decade alone. But growth in the number of people flying has more than offset those efficiency gains.
Until 1997, passenger growth averaged about nine per cent per year. Since then, it has averaged about five per cent, even accounting for the temporary dip that followed the Sept. 11, 2001 terrorist attacks, from which aviation swiftly recovered.
And there's no end in sight. Aviation is one of the fastest-growing sectors of the world economy.
Aircraft manufacturer Boeing projects that about 27,000 new planes will be delivered during the next 20 years, more than doubling the worldwide fleet, says Hodgkinson. And Airports Council International estimates the number of air travellers worldwide will double and air freight will triple by 2025, with the fastest growth in Asian markets.
In Britain, where cheap flights on low-cost carriers such as Ryanair and easyJet have accelerated the demand for flying, the government projects traffic will nearly triple to about 500 million passengers annually by 2030.
Growth of this magnitude, warns the Tyndall Centre, would destroy all hope that Britain and the European Union can stabilize carbon dioxide levels at or below the upper target of 550 parts per million. As other industries reduce their emissions, aviation will consume an ever-larger proportion of the carbon budget.
Even if aviation grows more slowly than at present, says the Tyndall report, "the EU could see aviation accounting for between 39 per cent and 79 per cent of its total carbon budget by 2050, depending on the stabilization level chosen. For the UK, the respective figures are between 50 per cent and 100 per cent."
To compensate for aviation's projected 2050 emissions, says a study by the Environmental Change Institute at Oxford University, "all other sectors of the UK economy would need to reduce their emissions by 71 per cent to 87 per cent instead of the currently planned 60 per cent from 1990 levels.
"There is no sign that this can or will happen. The existing 60 per cent target is already extremely challenging."
Worldwide, the Oxford study concludes that even by the most conservative estimates, carbon dioxide emissions from aviation will quadruple between 1990 and 2050. Other forecasts suggest emissions could grow by more than 10 times during that period.
BLUE SKIES, DIRE WARNINGS
It's numbers like these that prompted George Monbiot to declare in Heat, his 2006 book on climate change, that "the growth in aviation and the need to address climate change cannot be reconciled."
According to Monbiot, flying is one of the most destructive things we do. Though carbon emissions per passenger kilometre for a fully loaded airliner are comparable to a car carrying three or four people, an airplane can travel as far in a single day as an average car does in a year, he points out.
A single London-New York return flight, he writes, produces about 1.2 tonnes of carbon dioxide per person -- roughly the amount we each would be entitled to emit in a year if the world achieved the 90 per cent cut in carbon emissions that Monbiot advocates. "A 90-per-cent cut in emissions requires not only that growth stops," he observes, "but that most of the planes which are flying today are grounded."
Environmental icon David Suzuki recently told the Vancouver Sun that the amount of greenhouse gas generated by flying "is just intolerable to me." He has drastically reduced his own flying, will accept most speaking engagements only if he can do them by video-conferencing, and says his trip this year to Australia, a place he loves, was almost certainly his last.
It's not just environmentalists raising the alarm. "We may see an approaching perfect storm now for aviation," says Hodgkinson, a former director of legal services for the airline industry's leading body, the International Air Transport Association (IATA).
While most North Americans are still only dimly aware of aviation's contribution to climate change, in Europe, and especially Britain, the debate has been raging for some time.
In the UK, activist groups such as Plane Stupid have sprung up to fight airport expansions and agitate for new taxes and charges to discourage flying. Their tactics include direct action reminiscent of Greenpeace in its heyday of in-your-face activism.
In the past year, British anti-aviation activists have blocked airline offices, grounded planes by occupying an airport taxiway, shut down travel agencies and handed out free rail tickets to airline passengers.
Their actions have raised concerns in the UK about aviation's environmental impact. They are also starting to shift attitudes. European polls indicate a growing acceptance of the need to make flying more expensive. The surveys, says the Oxford study, "suggest that public opinion has recently passed a tipping point toward a more general acceptance for policies that constrain air travel."
In what may be an early sign of consumer unease about flight, load factors for Ryanair and easyJet have been slipping in recent months. In May, a Ryanair executive admitted the negative publicity about flying's environmental impact was affecting demand for flights "at the edges."
Also significant was the absence of any public outcry when Britain's government, citing environmental concerns, doubled air passenger duties in February. Travellers now pay between $21 and $170 in duties when they fly out of British airports.
THE FUTURE OF FLIGHT
The aviation industry has been slow to respond. At IATA's annual meeting in Vancouver in May, Leo Van Wijk, chief executive of KLM Royal Dutch Airlines, told his fellow executives that the industry has already "lost the PR battle" over aviation emissions.
That hasn't discouraged some from fighting back. Last month, the British Airline Pilots' Association (BALPA) issued a 72-page report that accuses critics of "intellectual laziness" and says casting aviation as a bete noir of climate change grossly exaggerates its role.
Even if all airplanes were grounded, that would only yield a three- to four-per-cent reduction in global CO2, the BALPA report says.
"By comparison with other forms of transport, let alone other contributors to climate change, the air transport industry is a small contributor to carbon emissions. This fact is ignored."
During the past 30 years, the aviation industry has improved fuel efficiency per passenger kilometre by 50 per cent, the report notes. Moreover, it has promised a further 50 per cent improvement in coming years. However, it adds, "it has to be acknowledged that demand is rising faster than improvements in technology, and this fact is contributing to that increase in the emissions generated by air transport."
Environmental critics forget that aviation is a "massive driver" of the world economy, the pilots argue. Directly or indirectly, the industry generates about 29 million jobs globally and contributes about 2.5 per cent of world GDP -- eight per cent including tourism. As well, about a quarter of the total value of trade in manufactured goods is flown to its markets.
As the debate heats up, airlines are starting to engage. Several, including Air Canada and Westjet, have recently aligned themselves with websites that sell carbon offsets that allow those who fly to ease their eco-guilt.
Passengers pay a voluntary fee, which is then invested in projects, such as tree planting or green research, that theoretically offset their carbon emissions. Even Queen Elizabeth has bought offsets for her flights.
Other airlines are playing up their green credentials.
Silverjet, a new British carrier offering cut-rate business-class service from London to New York, boasts that it's the world's first carbon-neutral airline. It includes a mandatory carbon offset contribution in its ticket prices. KLM has just signed an agreement with the World Wildlife Fund to drastically reduce its CO2 emissions.
Britain's easyJet has unveiled a prototype for an "ecoJet" based on existing technologies that it claims could halve carbon emissions. The new plane could be available as early as 2015, it says.
And Flybe, Europe's largest regional carrier, announced last month it has become the world's first airline to introduce an aircraft eco-labelling scheme. Passengers will be given a detailed breakdown of the carbon emissions, fuel consumption and noise patterns of their aircraft. They can then decide whether to carbon-offset their trip.
Airplane manufacturers Boeing and Airbus are waging a public-relations war over whose new jet will be more environmentally friendly.
- - -
Air Travel by the Numbers
2.1 billion
Number of scheduled airline passengers in 2006
4.5 billion
Number of passengers expected to fly annually on charter and scheduled airlines by 2025
23,000
Number of aircraft in the worldwide airline fleet at the end of 2006
27,000
Number of new aircraft expected to enter service by 2025
2 to 3
Percentage of man-made carbon dioxide emissions emitted by aviation
18
Percentage emitted by road transport
85
Average number of kilograms of greenhouse gas emitted per 100 kilometres by aviation
5
Percentage annual growth in air passenger traffic
1 to 2
Anticipated percentage annual improvement in aviation efficiency
3.5
Litres of fuel burned per passenger per 100 kilometres by modern jets
Less than 3
Target fuel consumption per passenger per 100 kilometres for the new Boeing 787 and Airbus A380
87
Percentage increase in international aviation emissions since 1990
677
Number of orders Boeing has received for its 787 Dreamliner
115
Number ordered by Australian airline Qantas alone
5 million
Number of people employed directly by the aviation industry worldwide
29 million
Number of direct and indirect jobs worldwide
$1 trillion
Aviation's contribution to world GDP, equal to about 2.5 per cent
2,092
Number of airlines at the end of 2006
29.8 million
Number of scheduled airline departures in 2006
76
Percentage of seats occupied on airline flights last year worldwide
$60 billion
Amount spent annually by airlines on kerosene fuel
