One of the key problems in global warming is aircraft emissions.
The world's fleet of roughly 17,000 commerical aircraft produces a terrific amount of greenhouse gases which it also emits at high altitude where the effects are considerably more pronounced. Even the aircraft condensation trails (those white plumes you sometimes see overhead) are problematic because they trap the heat of sunlight.
The trouble is, nobody wants to take the blame for aviation GHGs. As George Monbiot explains in his book Heat, Tony Blair's ambitious target for British GHG emission reductions doesn't take into account aircraft emissions or their planned increase. He notes that, even if Britain otherwise meets its GHG reduction targets, the increased GHG from expanded commercial aviation will more than offset that. As Monbiot points out, Britain is embarked on an ambitious aviation expansion programme including new airport construction that adds the equivalent of one Heathrow per year.
Is this really true? All you need to do is read Boeing press releases to see that it's very true. Four years ago, Boeing predicted the commercial fleet would double to 34,000 aircraft by 2022. Boeing last week estimated that the global market would grow by almost 27,000 planes worth $2.8 trillion in the next 20 years, with 36% of that growth coming from Asia-Pacific.
This represents a massive increase in commerical aviation in just two decades and, despite the faint promises of cleaner technologies to come, we're going to be stuck with today's technology for the foreseeable future.
The biggest problem at the moment is that world governments continue to be reluctant to recognize this problem. Nobody wants to add aviation GHGs to their carbon equation. That would throw the books right out the window. Ultimately only governments can take responsibility for curbing aviation GHG emissions. Until that happens, take any of their climate change promises with a very large grain of salt.