The inconvenient truth about the carbon offset industry

In the concluding part of a major investigation, Nick Davies shows how greenhouse gas credits do little or nothing to combat global warming.

It is 20 months now since British Airways proudly announced a new scheme to deal with climate change: for the first time, passengers could offset their share of the carbon produced by any flight by paying for the same amount of carbon to be taken out of the atmosphere elsewhere. "I welcome warmly this move from BA," said the then environment minister, Elliot Morley.

And how much carbon has BA offset from the estimated 27m tonnes which its planes have fired into the air since that high-profile moment in September 2005? The answer is less than 3,000 tonnes, less than 0.01% of its emissions - substantially less than the carbon dispersed by a single day of its flights between London and New York. The scheme has been, as BA's company secretary, Alan Buchanan, put it to a House of Commons select committee earlier this year, "disappointing".

The project has failed, according to one well-placed BA executive, because one part of the company wanted to improve its image by going green while another part wanted to protect its image by saying nothing at all about the impact of air travel on global warming. The result was that the scheme was launched and then banished to a dark corner of BA's website.

That tension - between the demands of the planet and the imperatives of commerce - lies at the heart of the global response to climate change and, in particular, of carbon offsetting. The idea that we might cancel our own greenhouse gases by paying for projects that reduce the gases elsewhere was born in the early years of climate politics. It was adopted by the corporate lobby at the Kyoto summit in 1997 and has grown into a large but deeply troubled adolescent - confused, unpredictable, and difficult to trust.

Separately from the "compliance market" on which nations and corporations trade carbon credits in an attempt to hit their Kyoto targets, there has grown a smaller, voluntary market in which airlines, banks, car makers and energy companies queue up to offset their carbon and to encourage their customers to do the same. A Guardian investigation suggests that many of the schemes on offer here are well-meaning but thoroughly unreliable.

Here is the full article.