It is planned that the protesters will gather at 20 climate hot-spots around the world and be photographed from a satellite in orbit.

They are claiming that, to their knowledge, this type of synchronized global art project has never happened before.

Says Bill Grist, one of the organisers, writing on his blog, "On Nov. 27 (the opening weekend of the next big U.N. climate conference, in Cancun, Mexico) in 20 places around the world, we'll be gathering huge numbers of people – thousands at a time. Some will be in deserts, some on snowfields, some wading out into warm lagoons – any place with a good background. They will use their bodies to make giant images."

Digital Globe Satellite, a company that sells satellite imagery, will be donating services for free and making these images widely available.

Masses of human bodies are a relatively new medium with which to make art. But the organisers, with help from artist John Quigley (Spectral Q), have arranged one before at climate demonstrations in Poland (see picture).

The image contains the number 350 because scientists say 350 parts per million CO2 is the most we can have in the atmosphere if we want a planet "similar to the one on which civilization developed and to which life on earth is adapted".

> www.350.org