What is the real climate impact of flying and what can we do about it? (BBC info)

What’s the problem?

While aviation emissions may seem relatively low now, they are growing faster
than any other source of greenhouse gases in the UK. Brits currently take 200 million flights a year but if air travel
continues to increase at current rates this will rise to 600 million by 2030.
The Tyndall Centre for Climate Change Research estimates that before 2050, UK
aviation emissions could exceed the emissions budget of the whole UK economy,
wiping out hard-earned reductions in other areas.

What can we do?

We can fly less. Like it or not, analysts say that is the simplest way to reduce
passenger numbers in time to stop dangerous levels of climate change. But there
is good news: we don’t have to give up flying altogether. In fact, the majority
of flights are taken by a small percentage of people who fly frequently. In 2007,
for example, a third of all flights were taken by just 4% of the population who
took five or more flights a year. So the most effective change would appear to
be for frequent flyers to dramatically cut their air miles, while those of us
who fly more than twice a year cut down a little.

It needn’t mean missing our holidays either: since 27% of flights from Britain
go to Spain and 50% to the rest of Europe, taking the train is an increasingly
viable substitute.

Choosing to fly less often, to holiday in Britain or to visit Europe by train instead of flying offer some of the most significant CO₂ savings of any personal action.

Can technology help?

As yet there’s nothing that will prove effective enough soon enough to significantly
reduce aviation’s impact on climate change, but various proposals exist to improve
the efficiency of flying:

• Better air traffic management systems – this would include filling planes to capacity and therefore scheduling fewer
  flights
• More efficient planes such as the Airbus A380 could reduce emissions compared to older aircraft, but it would take decades
  to replace existing fleets and the savings are being outweighed by air traffic
  growth. Planes are becoming more efficient by about 1% a year, while the industry
  grows by 7% a year
• Alternative fuels – aircraft have flown on biofuel blends in recent test flights, but they are
  unlikely to be used on regular flights in the foreseeable future while technical
  issues remain to be addressed. There are also significant question marks over
  the sustainability of biofuels. The first manned hydrogen fuel cell plane recently carried two people in a
  test flight conducted near Madrid, but scaling this technology up for commercial
  passenger jets is expected to take at least 20 years, and would create contrails,
  which may further warm the climate
• Airships – you may laugh, but an airship running on non-flammable helium is one of the
  least polluting forms of passenger travel. An Atlantic crossing to New York would
  take around 45 hours. Before you rush to buy your ticket, this route is not yet
  commercially viable
• Flying more slowly – in a bid to reduce fuel, Belgium’s Brussels Airlines have cut weight on aircraft
  and started to fly more slowly on certain routes. This adds a minute or two to
  journey times and saves 1 million Euros on their annual fuel bill. Planes on other
  routes currently fly at pre-set speeds, putting a limit on such savings

What are the politicians doing?

Political progress on reducing aviation emissions might be categorised as, at
best, uneven. Unlike with trains, buses and cars, international flight emissions
are not included in the Kyoto protocol (the legally binding inter-governmental contract to reduce greenhouse gas emissions).
The reason for this omission, say governments, is that flights cross many international
borders, making it hard to identify who’s responsible for aircraft emissions.

Aviation will, however, be included in the European Emissions Trading Scheme (ETS) – but not until 2011. The Department for Transport anticipates plane travel
emissions will be capped at 2004/6 levels. Even then, scientists at the Tyndall
Centre suggest the ETS will do little to reduce actual plane travel emissions
because airlines will be able to increase passenger numbers through buying in
extra permits. And they predict that the small price rise proposed for plane travel
under the ETS will deter very few people from flying.

Meanwhile, UK government aviation policy – as set out in the 2003 aviation white paper – seems sure to result in large-scale aviation expansion, including a third
runway and sixth terminal at Heathrow. And Britain looks set to expand its airports
around the country on a scale greater than that envisaged by any other European
nation. Air operators claim this will benefit passengers by cutting congestion.
Campaigners respond that making flying more appealing will simply increase demand,
in turn increasing the need for further new airports and runways – a pattern demonstrated
by recent road-building policies which, they argue, have actually increased traffic
congestion.

Another criticism of Britain’s aviation policy is that the industry has an effective
subsidy of around £10 billion a year as no tax is levied on aviation fuel in the
UK, and plane tickets are VAT-free.

The government defends its policy on the grounds that aviation is critical to
supporting the UK’s world status as a hub for finance, industry and tourism.

What’s the climate impact of aircraft emissions?

Flying injects exhaust emissions directly into the upper part of the atmosphere,
where they cause the most damage. The effects of the resulting mix of chemical
reactions are complex and hard to calculate, occurring over timescales between
three days and 100 years. Even so, scientists believe that between 1992 and 2050,
the overall impact of these emissions will prove somewhere between 1.2 and four
times that of CO₂ at ground level. [This is now established, by the IPCC as x 3.   See link].       (Contrails add to this mix of effects. Made up of soot and water vapour,
scientists know that in some weather conditions contrails cause cirrus clouds
to form, which warm the climate further, though these effects are as yet poorly
understood).

What difference does this make in practice? Well, the CO₂ emissions of a return flight from the UK to Malaga for example are 480kg.  If you multiply by the lower estimate of 1.2, the true
extent of the damage would be 570kg – the same amount of CO₂ saved by recycling nearly 15,000 green bottles. At the upper end, emissions could top 1900kg. [
Multiplied by 3 it is about 1440 kg of CO2].

This factor is also relevant when assessing the overall contribution of aviation
to UK emissions. The government’s figures on the climate change impact of flying
are calculated based on domestic and international departures from the UK and
suggest it contributes only about 7% of the country’s CO₂ emissions.   But because of the extra impacts, research suggests that it’s likely
to create something closer to 11% [ more like 18% of the UK’s climate changing  impact,
using the new multiplier of 3].   of our national total.

Pub Facts  about flying, from the BBC:

One short-haul flight has the same potential to warm the climate as three months
worth of driving a 1.4 litre car

Less than half of Brits fly for their holidays

The average annual income of Heathrow passengers is £54,488

In 2006, British airports handled more than 200 million passengers and it is
predicted that that number will double over the next 15 years

56% of people are concerned about the environmental effects of air travel, but
only 10% have reduced the number of flights they take

One flight to Sydney generates emissions equivalent to driving a mini around
the earth 640 times

To avoid more expensive airspace, certain airlines take longer routes to the
Canary Islands, creating an extra three tonnes of CO₂ per flight

Over 10 years, all UK CO₂ emissions (transport, farming, housing and construction) fell by 9%, apart from
flight emissions, which doubled

One short-haul flight has the same potential to warm the climate as three months
worth of driving a 1.4 litre car

A third runway at Heathrow is predicted to raise CO₂ pollution by the equivalent of the national output of Kenya

Over half of Brits never fly

Flying to Australia and back is the energy equivalent of leaving over 15 low-energy light bulbs on for a year