London’s consumption based greenhouse gas emissions

Tackling London’s greenhouse gas (GHG) emissions is a huge challenge. The impact of these emissions goes far beyond the city’s boundaries. From the electronics we buy and the food we eat to the clothes we wear, most are produced and transported globally. The Mayor, together with London Councils and ReLondon, has jointly commissioned Leeds University to develop a historic trend of consumption-based emissions for London. It uses the latest available data (running from 2001-2021) on average expenditure on different types of goods and services. This methodology aligns with equivalent national government datasets at the UK level. **Findings** London’s consumption-based emissions in 2021 were around 80 MtCO 2 e. They’ve fallen by 24 per cent since 2001, despite the city’s population increasing by 1.4 million over that time. This means emissions per head have reduced by 35 per cent (from 13.9 to 8.98 tCO 2 e per person). The biggest drop in consumption-based emissions was between 2008 and 2009 during the global financial crisis, when households’ average spending decreased. Post 2009, emissions stabilised then steadily reduced from 2014 to 2020, bar a small increase from 2017-2018. This period of emissions reduction has been mainly driven by decarbonisation of the UK electricity sector. **The national context** London’s per capita consumption-based footprint is slightly lower than the UK average. It also follows a similar trend in reduction over the same period. However, at a sector level there are some cases where the per capita emissions for Londoners are different, for example: * **Transport** – London’s use of transport is unlike any other region in the UK. Private transport emissions are much lower than any other region, and public transport emissions are the highest in the country. As a result, London has the lowest per capita transport emissions of any region and is lower than the UK average. However, London also has one of the highest per capita aviation emissions. Transport emissions were still unusually low in 2021 due to the ongoing impact of the COVID-19 pandemic. * **Housing, water, electricity, gas, other fuels** – Compared to other regions in the UK, Londoners spend less on heating and power. This is a function of increased household occupancy rather than lower energy bills and more efficient homes. * **Food and drink** – Compared to other regions in the UK, Londoners spend less on meat, which contributes to a lower food footprint per capita. **The international context** The Mayor wants to recognise the full environmental impact of London’s consumption by publishing this data. We hope this will encourage more cities to publish their consumption-based emissions data so we can identify similarities and work together to bring these emissions down.应对伦敦的温室气体（greenhouse gas，GHG）排放是一项艰巨挑战。此类排放的影响远超伦敦市辖区范围。从我们购置的电子产品、食用的食品到身着的衣物，绝大多数商品与服务均在全球范围内完成生产与运输。 伦敦市长联合伦敦市政会（London Councils）与ReLondon，共同委托利兹大学构建伦敦消费端温室气体排放（consumption-based emissions）的历史趋势数据集。该研究采用了2001年至2021年期间各品类商品与服务的平均支出最新公开数据，其研究方法与英国国家级同类官方数据集保持一致。 **研究结果** 2021年伦敦消费端温室气体排放量约为80百万吨二氧化碳当量（MtCO₂e）。尽管同期伦敦人口增长了140万，较2001年仍下降了24%。这意味着人均排放量降低了35%，从每人13.9吨二氧化碳当量（tCO₂e）降至8.98吨。 消费端排放的最大降幅出现在2008至2009年全球金融危机期间，当时英国家庭平均支出有所下滑。2009年后，排放量趋于平稳，随后从2014年至2020年持续下降，仅在2017至2018年间出现小幅回升。此阶段的排放下降主要得益于英国电力部门的脱碳转型。 **国家层面对比** 伦敦人均消费端碳足迹（carbon footprint）略低于英国平均水平，同期减排趋势也与英国整体相仿。但分领域来看，伦敦居民的人均排放量存在部分差异，举例如下： * **交通运输**——伦敦的交通出行模式与英国其他地区截然不同。其私人交通排放量远低于英国其他所有地区，而公共交通排放量则为全国最高。因此，伦敦是全英人均交通运输排放量最低的地区，且低于英国平均水平。但伦敦的人均航空排放量也位居全国前列。受新冠疫情持续影响，2021年伦敦交通运输排放量仍处于异常低位。 * **住房、水、电力、燃气及其他燃料**——与英国其他地区相比，伦敦居民在供暖与用电上的支出更低。这一现象源于家庭居住人数的增加，而非能源账单降低或住宅能效提升。 * **食品与饮料**——与英国其他地区相比，伦敦居民在肉类上的支出更少，这使得人均食品碳足迹相对更低。 **国际层面背景** 伦敦市长希望通过发布该数据，全面体现伦敦消费模式带来的全链条环境影响。我们期望此举能鼓励更多城市公开其消费端排放数据，从而让各方得以总结共性、携手合作，共同降低此类排放。