The ambitious CO2 Human Emissions (CHE) project of the European Commission, coordinated by ECMWF, started in 2017 with the objective to explore the development of a European system to monitor carbon dioxide (CO2) emissions across the world related to human activity. In its second year, the project made noticeable progress towards its key deliverables.

CO2CO2 concentrations (parts per million) simulated by the CHE project for 12 December 2015, the day the Paris Agreement was adopted. The Paris Agreement aims to strengthen the global response to the threat of climate change and was agreed at COP 21, the 21st Conference of Parties of the United Nations Framework Convention on Climate Change (UNFCCC), held in Paris from 30 November to 12 December 2015.

The key requirements that CHE has to meet include isolating emissions related to human activities from other sources of CO2 in the atmosphere; monitoring CO2 emissions from local to global scales; and providing uncertainty estimates. A full prototype for such a system is planned to be available in 2023, with an early version expected in 2021.

The focus of 2018 was on conducting preliminary work towards the development of this prototype, to enable work to start in earnest in early 2019. This included producing global simulations of atmospheric CO2 using the major global sources of fossil fuel emissions along with biosphere CO2 exchanges and their transport.

The project used the capabilities provided by the EU Copernicus Atmosphere Monitoring Service (CAMS) to produce a long “nature run” high-resolution CO2 simulation as well as CO2 ensemble simulations. The ensemble approach was thoroughly tested over the year, with a decision to adopt it being reached at the end of 2018. In that approach, multiple simulations are run with a range of slightly different initial conditions and slightly perturbed surface fluxes and transport. The resulting spread of results gives an indication of the different sensitivities of the observed CO2 variability and the confidence we can have in the data.

At the end of 2018, the project was on track to meet its deliverables, having developed a clear understanding of the basic requirements for the prototype system and in principle knowledge of how to build it, based on climate and environmental reanalysis experiments and enhanced data assimilation adapted to CO2.

About CHE

CHE, as a Coordination and Support Action, brings together expertise from partners in 8 European countries and a consolidated approach to building an operational CO2 emission monitoring capacity. The CHE consortium includes partners from industry, academia, the research sector as well as international organisations. The consortium members are at the forefront of developments in the compilation of emission inventories, the observation of the carbon cycle from ground-based and satellite measurements, the process modelling of the carbon cycle, atmospheric transport modelling, and data assimilation and inversion systems.

The CHE project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no 776186.