Metrics for Biogeophysical Climate Forcings from Land Use and Land Cover Changes and Their Inclusion in Life Cycle Assessment: A Critical Review

The regulation by vegetation of heat, momentum, and moisture exchanges between the land surface and the atmosphere is a major component in Earth's climate system. By altering surface biogeophysics, anthropogenic land use activities often perturb these exchanges and thereby directly affect climate. Although long recognized scientifically as being important, biogeophysical climate forcings from land use and land cover changes (LULCC) are rarely included in life cycle assessment (LCA). Here, I review climate metrics for characterizing biogeophysical climate forcings from LULCC, focusing mostly on those that do not require coupled land-atmosphere climate models to compute. I discuss their merits, highlight their pros and cons in terms of their compatibility with the LCA framework, outline near-term practical guidelines and solutions for their integration, and point to areas of longer term research needs in both the climate science and LCA research communities.