This ITU-T Recommendation gives general guidance for city level environmental assessments related to ICT, and provides a description of methodologies to be used for the assessment of the environmental impact of ICT in cities. In this first edition of this Recommendation, the assessment is limited to energy consumption and GHG emissions. The present Recommendation is divided in two parts. " Part I relates to the first order effects from the use of ICT goods and networks in city´s organizations and households. " Part II relates to the first and second order effects from ICT projects and services applied in the city This Recommendation provides specific guidance in setting the city boundaries, preparing and performing the assessment of ICT related GHG emissions and energy consumption at city level.