The Independent, a British newspaper, has a report on a study presented at an FAA conference recently that claims air travel is a significantly larger contributor of carbon emissions to the atmosphere than previously assumed:
An unpublished study by the world's leading experts has revealed that airlines are pumping 20 per cent more carbon dioxide into the atmosphere than estimates suggest, with total emissions set to reach between 1.2 billion and 1.5 billion tonnes annually by 2025.
The report, by four government-funded research bodies, is one of the most authoritative estimates of the growth of pollutants produced by the industry. It was presented to a conference co-organised by the United States' Federal Aviation Authority but not given a wider audience.
Combining data produced by the leading emissions-modelling laboratories in the US, Britain and France, the study found that the number of people seriously affected by aircraft noise will rise from 24 million in 2000 to 30.3 million by 2025, despite the introduction of quieter jets, and that the amount of nitrogen oxides around airports, produced by aircraft engines, will rise from 2.5 million tonnes in 2000 to 6.1 million tonnes in 2025.
The CHSRA has not provided any firm estimates of how much carbon emissions will be saved from air travel specifically - their 17.6 billion pounds of carbon per year estimate includes air and auto travel - but this study suggests that even the CHSRA numbers may significantly understate the savings.
On that basis alone high speed rail is worth building, as part of California's strategy to fight global warming. The AB 32 goals - reduction of CA carbon emissions to 1990 levels by 2020 - is a modest goal, but it will not have a chance of being met without investment in high speed rail. The full system won't open until around 2020, but portions of it will open before then, and will provide immediate action to stabilize our changing climate.
Opponents usually ignore this topic, since to acknowledge the need to act on global warming is to acknowledge the need for high speed rail. Instead they continue to suggest that airlines will handle the bulk of California's travel needs, or that airlines will adapt. The airlines themselves make this claim, from the same Independent article:
The International Air Transport Association, which represents 240 airlines, said it was working towards producing binding targets to reduce CO2 emissions. "With fuel costs doubling in the last year, airlines already have an incentive to work towards greater efficiency," a spokesman said. "There has been a 70 per cent improvement in fuel efficiency in the last four decades. Aviation is a benchmark of environmental responsibility for others to follow."
In fact, most of this "greater efficiency" is coming in the form of longer flying times or cutting service and reducing flights, including on the LA-SF route. New airline technologies designed to save on fuel, such as the Boeing 787 Dreamliner, are experiencing significant delays amid technical problems.
The fact is that the airline industry is in serious trouble. Rising fuel costs and the growing awareness of their impact on global warming both mean that we will see a reduction in airline services. The airline industry will not disappear, but where it can be replaced with more efficient forms of travel - like high speed rail to connect cities within states - it will. If the enormous levels of carbon emissions from airlines don't convince us of the need to build high speed rail, perhaps the fuel-induced reductions in airline service will.