Using recycled materials like those that Zoe uses to build her race car means additional resources from Earth’s spheres do not have to be used. By using recycled cardboard and skewer, Zoe helps keep fewer trees in the biosphere from being cut down. Using old washers means no new metal needs to be mined from the geosphere. Using old CDs that would have otherwise ended up in a landfill lessens impact on the geosphere. Using a reusable water bottle instead of a single use bottle means less plastic needs to be made.