Everything we do produces carbon (even breathing!), so this is the common unit of measurement we use when talking about our impact. Unless we are working carbon neutrally (i.e. all the energy we need is obtained from renewable sources like the sun or wind), everything we do has an output that can be converted into an amount of carbon units (generally measured in kilos or tonnes). Different activities expend different amounts of carbon. When we talk about our carbon footprint, we are talking about the impact a specific activity has on the environment. This could be driving a car to the studio, the production itself, or the industry as a whole.