Around 100 environmental campaigners have staged a protest outside the Scottish Parliament calling for world leaders to act against climate change.

The campaigners joined together to form a human banner in the shape of the number 350 outside Holyrood on Saturday afternoon.

The number reflects the highest amount of carbon dioxide - 350 parts per million (ppm) - that it is thought the earth's atmosphere can safely hold.

The day is part of a series of demonstrations in 150 countries for the International Day of Climate Action, organised by NGO 350.org.

The action will take place just six weeks before the United Nations Climate Change Conference in Copenhagen, where world leaders will draw up a new treaty on the earth's climate.

Campaigners are pushing for the 350ppm carbon dioxide level to be incorporated as a target in the new treaty.

One of the organisers of the Edinburgh event, Keith Baker said: "Getting back to 350 means transforming our world.

"It means building solar arrays instead of coal plants, it means planting trees instead of clear-cutting rainforests.

"Getting to 350 means developing a thousand different solutions - all of which will become much easier if we have a global treaty grounded in the latest science and built around the principles of equity and justice."