Users of the Green-O-Meter application on the social network are encouraged to answer a series of questions about the environment and day-to-day activities that are then translated into green rankings.
Users can then pass the quiz onto friends and compare rankings, as well as setting themselves challenges to improve their scores.
The application follows last year's launch of Barclaycard Breathe, a credit card aimed at promoting greener spending that secured a £1m donation towards environmental projects in its first year.
The new application is likely to be the first of a flurry of new service launches on Facebook. Last week, its chief executive Mark Zuckerberg announced that it is working on a redesign that will allow some of its popular applications to become more accessible. He suggested that Facebook might, in the future, feature functions such as search.
Additionally, Zuckerberg revealed that the site is open to the prospect of working with Google. He cited Google's search engine and its social networks, such as Orkut, as the "pieces outside of what Facebook does" that could become part of the Facebook platform.
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