An article of Aljazeera - the topic says everything...
You're buying an airplane ticket online. Scroll to the bottom of the website, and there's an option to "buy carbon credits" to "offset" the climate change-inducing emissions you are about to produce during your flight.
It sounds like an attractive, market-based way to appease your environmental conscience - and quite affordably, too. But what are you actually buying? And how much - if any - difference can it really make in the fight against global warming?