Energy and carbon footprint: numbers matter in low energy and low carbon choices

•Energy and carbon footprint numbers can provide useful guiding principles in making low energy and low carbon choices.•Energy and carbon footprint provide consumption based estimates.•Dearth of information constrains full estimation of footprints.•Database using common methods can facilitate footprint comparability.•Voluntary reporting by consumers is a good start.

Consumption based approach to assess level of energy use and carbon emission is evolving. Practical examples from various studies in the context of different sectors and countries are used to demonstrate how energy and carbon footprints are being estimated and how some efforts to come up with standard method are evolving. These estimates can very well be linked to a decision making process. Uniform methodology and access to data can help generate comparable numbers across consumer categories and countries.