The 'CO2 Shoes' are touted as being "a shoe with no footprint."
The unusual statement refers to the materials and production of the shoes -- as they do not defy physics and the inevitability of leaving a footprint when walking on soft or dirty surfaces -- but are made without leaving a carbon footprint in the process of their creation. Production in most industries involves some sort of negative impact on the environment, with carbon emissions being a large part of that impact. The footprint-less shoes were created as part of the 'Carbon XPRIZE' global competition that was created to "develop breakthrough technologies that will convert CO2 emissions from power plants and heavy industry into products."
The CO2 Shoes are somewhat misleading in their marketing but rather than being the primary footwear choice for criminals around the world, they have a much more positive global impact that was created in response to the climate crisis the world is currently facing.