As the world moves to cities, so does art. And just as art can inspire political action and resistance, so can the walls of the town become canvases for important street art messages. The street and graffiti art on this list is perfect for spreading words about environmentalism and climate change to a broader audience.

There's art for aesthetics, and there's art with meaning. Same goes for street art - some are just ugly and indecent doodles, while other graffiti drawings discuss pressing global issues. This street art uses simple slogans and provocative images to cover essential and inspiring ideas about global warming and social issues in ways that are easy to remember. Such a technique can inspire people to take action or at least remind them about important issues that they may have forgotten.

Scroll down below for our list of the most powerful messages left on city walls and pavements and prepare to be inspired for a change.