places that donate these items to the store. do you think a concept like this could work in the united states? >> yeah, i think this concept could work anywhere. wherever food is wasted. >> reporter: keith annal helps run the market and notes britain is the biggest food waste offender in the european union. >> what we want to do is get the food out of those bins and just offer it to people. >> reporter: they test for safety by smelling, sampling, and visually inspecting the food. if it's bad, they throw it away. >> i'll just put my money in. >> reporter: since all the items are donated, customers pay whatever they want. >> absolutely brilliant to think that all of this stuff is being saved from going into landfill. >> reporter: the real junk food project hopes this is the start of a global movement getting consumers to think twice before tossing. teri okita, cbs news, west yorkshire, england. >> ninan: a global movement indeed. when we return, scientists on a mission to asset world's tallest trees.