The phrase "cleaner world" means a world where there is less pollution, dirt, and harm to the environment. It refers to a place that is safer, healthier, and more sustainable for both humans and nature. Full definition
Similar and related words and phrases are presented below.
We are now faced with the painful realization that the iPad has not cleansed the world of the heathen eReaders. (dealsagar.com)
Better to cleanse this world by destroying it than to let us go about our complacently wicked ways. (religion-online.org)
If your hotel doesn't participate in Clean the World (check for signage or consult the website), leave a brief note at the front desk for the general manager to suggest they join. (travelskills.com)