The London Energy and Greenhouse Gas Inventory (LEGGI) 2014 shows greenhouse gas emissions and energy consumption for London. This is an interim version of the LEGGI 2014, which will be confirmed when final data on energy use is published by the Department of Business, Energy and Industrial Strategy (BEIS) and Transport for London (TfL), expected in late 2017. The LEGGI shows estimates of energy consumption and carbon dioxide equivalent (CO 2 e) emissions from homes, workplaces and transport within the Greater London area. It is produced by the Greater London Authority on an annual basis to measure progress against the Mayor's Climate Change Mitigation and Energy Strategy. The LEGGI uses sub-regional energy (electricity, gas and other fuels) and CO 2 e data published by DECC/BEIS for homes and workplaces, and data from the London Atmospheric Emissions Inventory (LAEI) for energy and CO 2 e data for transport. DECC/BEIS E mission F actors (EFs) are used to estimate greenhouse gas (GHG) emissions from stationary and mobile sources of energy use in the LEGGI. These EFs are produced annually based on the national greenhouse gas inventory two years prior. E.g. 2016 EFs are calculated using national GHG emissions and energy use inventory data from 2014. So, for this 2014 LEGGI we have applied DECC/BEIS 2016 EFs to 2014 energy use to provide a more accurate estimate of GHG emissions in 2014 that is consistent with UK inventory data for 2014. We have retrospectively applied this method for EF selection to data from 2010 onwards to ensure consistency of approach and allow trends in CO 2 e estimates to be assessed. Interim results show that in 2014, London’s CO 2 e emissions were 37.8 million tonnes. This is a 16 percent reduction on 1990 levels and a 25 percent reduction since the peak of emissions in 2000. This is despite an ever-increasing population – an increase of 26 percent since 1990. London’s per capita emissions were estimated at 4.4 tonnes of CO 2 e in 2014, their lowest since 1990.