Paris accelerates its low-carbon transition by testing the first urban service for accurate measurement and tracking of CO₂ emissions

The goal in Paris is to build a carbon-neutral, 100% renewable-energy city by 2050. The capital needed a tool for measuring local greenhouse gas emissions that could meet the challenge of its transition to carbon neutrality. It wanted to work with Origins.earth and the LSCE, as Yann Françoise, the city of Paris Climate, Energy and Circular Economy Manager, explains: “Paris has supported the Origins.earth project since its creation in order to benefit from the latest scientific advances in favour of the climate transition in Paris. It will open new avenues for managing the low-carbon transition, quickly evaluating the impact of projects and engaging in a new form of dialogue with Parisians.”

Traditional methods for estimating CO₂ emissions in urban environments are based on inventories that offer a picture of emissions two or three years late. Local authorities mostly have to rely on simple Excel spreadsheets containing meagre field data or statistics, sometimes supplemented by default values, which take a long time to collect, process and check. Knowledge of local greenhouse gas emissions is thus always subject to a time delay.

The pilot project’s science and technology chain is based on:

• data measured by the LSCE’s existing network of sensors and the new generation of sensors built and installed by Origins.earth,
• quality control of the urban data generated,
• a meteorological model,
• modelling of CO₂ dispersion in the atmosphere,
• generating inventories of emissions across the territory and analysing the results,
• designing indicators and a method of representing the results on a monthly scale.

“Our technology stands out by offering a dynamic vision almost in real time. The LSCE’s high-precision measuring stations, and our own, detect clouds of CO₂. We can then model the weather to determine where they are coming from.” David Duccini, CEO of Origins.earth

This world-beating innovation was recognised by the World Meteorological Organization nearly three years ago.

An analysis of CO₂ emissions carried out during the second lockdown in France, from November to December 2020, revealed a significant drop in emissions of around 35% for the city of Paris and 22% for the Ile-de-France region.

The first lockdown, from March to May 2020, caused a sharper fall in emissions of around 54% for Paris and 42% for Ile-de-France. The less pronounced reduction in emissions during the second lockdown is partly due to the fact that economic activity and road traffic remained at a higher level at the end of 2020.

“The lockdown led to a very brief drop in emissions, and to meet the City of Paris' reduction goals, continued efforts with systemic changes will be required”, points out Philippe Ciais, a member of the French Academy of Sciences, the LSCE research director and a project participant.

The partnership project between Origins.earth, the LSCE and the city of Paris also ultimately aims to establish a pilot observatory to measure CO₂ emissions in Paris and the Ile-de-France region. The goal is to monitor the evolution of greenhouse gas emissions and track the impact of measures to reduce CO₂ emissions. For Yann Françoise, “obtaining emissions data in almost real time is a useful innovation for Paris and all other cities.”

Additional sensors will be installed to provide the local authority with:

• More frequent data: The volume of CO₂ emissions originating from fossil fuels with at least monthly frequency would enable the trends operating across the territory to be estimated;
• More precise, spatialised data: A geolocated register of CO₂ emissions and the potential for reducing them, with estimates that will target uncertainty levels below 10% – these can be much higher with current methods;
• Contextualised data: The trial aims to determine the relative contributions of emitting activities (buildings and road transport in particular) and the decisive factors.