It’s not all that unusual to see compostable cups these days, but not every restaurant actually composts them. Many just throw them away. Adding compostable materials to landfills increases the amount of methane produced by those landfills. Methane is a much more potent greenhouse gas than carbon dioxide.
But Sweet Green does it right.
Note 1: These cups are made from corn, and it is more likely than not that the corn is genetically modified. There isn’t enough organic corn to meet the demand.
Note 2: The use of staple foods like corn for things like cups helps to raise the price of corn and make it difficult for poor people to afford it. It would be much better if all restaurants served their food in durable, reusable containers.