All eyes will be on the aviation industry which has now pledged to reduce its emissions to half its 2005 levels by 2050.

The BBC reports that British Airways chief executive Willie Walsh has put up a series of proposals: These involve to halving net carbon dioxide emissions by 2050, compared with 2005 levels, making the entire industry's growth carbon-neutral by 2020, improving fuel efficiency by 1.5% each year over the next decade and submitting plans for joining a global carbon trading scheme to the United Nations by November 2010.

Mu suspicion is that the aviation is trying to dodge the criticism about being one of the drivers of climate change. Let's be blunt: the only way they can reduce emissions is by reducing the number of flights and that's not going to happen. This is just a PR stunt.

As Jeffrey Gazzard, a board member of the Aviation Environment Federation writes in a letter to the Guardian , it just doesn't add up.

Gazzard writes: "The key word from Mr Walsh that exposes his claims is "net". Carbon offsets are a significant part of the aviation industry's menu, but are no substitute for real cuts in emissions. The use of biofuels in aircraft is, despite a masterly PR campaign featuring Boeing and Branson, the Batman and Robin of aviation's greenwash hype, unlikely to deliver the promised "10% by 2017" contribution. There are no sustainable biomass feedstocks or production facilities that could produce a safe kerosene alternative with a zero carbon footprint or less by then."

This is just a feeble attempt by the aviation industry designed to avoid a carbon tax.