Life cycle assessment (LCA) analysts are increasingly being asked to conduct life cycle‐based systems level analysis at the earliest stages of technology development. While early assessments provide the greatest opportunity to influence design and ultimately environmental performance, it is the stage with the least available data, greatest uncertainty, and a paucity of analytic tools for addressing these challenges. While the...

Summary There is consensus on the importance of upstream methane (CH 4 ) emissions to the life cycle greenhouse gas (GHG) footprint of natural gas systems, but inconsistencies among recent studies explain why some researchers calculate a CH 4 emission rate of less than 1% whereas others calculate a CH 4 emission rate as high as 10%. These inconsistencies arise from differences in data collection methods, data collection time f...