The overall construction carbon impact of HS2 Phase One is reported in the relevant Environmental Statement*. This aspsessment presents a reasonable worst-case scenario and assumes fossil-based diesel is used for heavy plant and related transport. The statement was produced to accompany the then High Speed Rail (London - West Midlands) Bill. In the four years since publication, technological improvements and adoption of best working practices will have superseded many of the findings therein, including HS2 Ltd’s adoption of a target to cut construction carbon emissions by 50% against industry baselines. Contributors to achieving this target include the adoption of plant and facilities that do not use fossil-based diesel.