Cars are a major source of climate-warming greenhouse gases. As the earth gets hotter, extreme weather events will become common and threaten lives around the world. Every year, Greenpeace promotes Car Free Day, trying to change people’s driving behaviour by getting them to stop driving for a day.

To help people realize that driving and climate change go hand in hand, we used a visual consisting of parallel tire tracks. In one, we show a story of the fun and merriment driving brings you. In the other, we show the death and destruction caused by the resulting climate change. These parallel stories illustrate the message that “You’re not just driving your car, you’re driving environmental devastation”.

People were shocked to see how true to life the stories in each tire track was. As a result, the campaign helped drive a 13% increase in participation – even Hong Kong’s head of government, Donald Tsang, supported the event by going to work on foot.