PAS 2050, the upcoming carbon footprinting standard from the UK department of environment and the Carbon Trust, is likely to fill a vacuum that exists today. There are no universal standards today, other than the ISO standards for process LCA. A standard is needed for reliably comparing footprints across multiple products. For those interested in the nuts and bolts of the LCA methodologies likely to be recommended by PAS 2050, there is a comprehensive methods review that sheds some light. The review recommends a fully integrated hybrid LCA approach, where process LCA is combined with input-output LCA (based on input-output economic data and environmental factors) in a rigorous manner, dealing with typical limitations such as feedback loops, cut-offs in process modeling, and general difficulties in data collection. One missing item: dynamic time-based footprint analysis (see previous post).