"It's a photo of me at Tangiers Port on a stormy day in November 2011. The boat was hours late and the sea was heaving but I wouldn't have swapped the overland journey for the world.

It's a wonderful short trip, which saw our boat followed by a pod of dolphins, and the cultural divide between the two shores is stark.

The Carbon cut by travelling overland to Morocco is quite significant too!"

Matthew Butcher, London

This photo is just one example of progress towards a low-carbon world, and we're collecting more as part of our #itshappening project.

• Check out the gallery of #itshappening images
• Submit your own example