Not all cups are created equal. According the Institute of Lifecycle Environmental Assessment
a reusable cup must be used a certain number of times to make up for the energy used to create it.

Reusable vs. Disposable Cups

The chart shows how you must use a ceramic mug 39 times to make it more efficient than a paper disposable cup. Read a full article about this at Make Magazine online.

This chart though doesn’t address things like these vessel’s impact on the planet once they break or are thrown away. The disposable cups take up more space in landfills and cannot be recycled like the reusable cups. I find myself using my steel and plastic reusable mugs at more than coffee shops. I get some strange looks at restaurants where they automatically just give you a disposable cup. I use it as an opportunity to say, “No thanks I don’t want a disposable cup because they come from trees/oil.”