Verifying Emissions of Climate Forcers

Project Information

EYE-CLIMA

Grant agreement ID: 101081395

DOI

10.3030/101081395

EC signature date 4 October 2022

Start date 1 January 2023

End date 31 December 2026

Funded under

• Climate, Energy and Mobility

Total cost

€ 4 994 262,50

EU contribution

€ 4 994 262,25

Coordinated by

STIFTELSEN NILU
Norway

Periodic Reporting for period 2 - EYE-CLIMA (Verifying Emissions of Climate Forcers)

Reporting period: 2024-07-01 to 2025-12-31

Summary of the context and overall objectives of the project

The Global Stocktake, and thus the success of the Paris Agreement, hinges on the information nations provide about their emissions through National Greenhouse Gas Inventories (NGHGIs). Current methodologies laid-out by the IPCC for reporting emissions are generally built around the use of economic activity data and emission factors. Although they are designed to be transparent, they can have significant uncertainties. The 2019 refinement of the IPCC Guidelines recognises the need for independent verification of NGHGIs, especially using atmospheric observations.

EYE-CLIMA will address this need for independent verification by developing observation-based methods to a level of readiness where they can be used to determine emissions at national and sub-national scales and for verification of NGHGIs. The methodology involves using process-based and data-driven models to simulate GHG fluxes, and models of atmospheric transport and chemistry to assimilate atmospheric observations. This approach is referred to as “atmospheric inversion”. EYE-CLIMA will have a strong focus on improving the atmospheric inversion method, and better quantifying the uncertainties in the emissions derived to increase the reliability and utility of the approach.

Through engagement with NGHGI compilers, EYE-CLIMA, will develop flux data products for CO2 (LULUCF sector), CH4, N2O, SF6 and five HFCs and black carbon (BC), which will be tailored to their needs. The emissions of CH4 and BC will be attributed to broad source sectors that can be compared with groups of IPCC sectors used in NGHGIs. The methodology for the atmospheric inversions and how to use these for verification of NGHGIs will be described in good practice guidelines.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

EYE-CLIMA has compiled an inventory of CH4 point source emissions using hyperspectral satellite instruments. For this, publicly available data from PRISMA, EnMAP and EMIT were analysed and 14 emission locations were identified in Europe. Emissions have been estimated for 5 landfills, 6 coal mine ventilation shafts and 2 unknown sources.

The feasibility of using satellite measurements of N2O to support emissions estimation has been evaluated. N2O retrievals from the SWIR GOSAT-2 and the TIR IASI satellite instruments have been compared to 3D atmospheric N2O fields from the CAMS N2O inversion product to evaluate their consistency.

EYE-CLIMA has produced maps of above ground biomass (AGB) and above ground carbon (AGC) for Europe annually from 2011 to 2023 at 25 km using satellite measurements of Vegetation Optical Depth from the L-band of the SMOS satellite (L-VOD). The uncertainty from the calibration of the L-VOD signal to AGB was evaluated by comparing the results with national AGB stocks from national forest inventories (NFI). Variations of AGC were examined for the 2018 and 2022 drought events and for the wet year 2021.

EYE-CLIMA has run high resolution simulations of CO2, CH4 and N2O fluxes from process-based models. The results of CO2 (Net Biome Product, NBP) and N2O fluxes were compared between the models ORCHIDEE and LPJ-GUESS. For NBP, the results were also compared with independent estimates (the FLUXCOM and FluxSat datasets). In addition, the uncertainty in the N2O fluxes modelled with LPJ-GUESS due to the representation of management practices was investigated. CH4 fluxes from peatlands, mineral and inundated soils were simulated at high-resolution using the JSBACH-HIMMELI model. The uncertainties in the CH4 fluxes due to wetland area map, climate data, and key model parameters were investigated.

Atmospheric inversions have been run for Europe for CO2 LULUCF, CH4, N2O, SF6 and 5 HFCs at resolutions between 0.5° and 0.2°. The uncertainties in the inversion results were assessed using ensembles. EYE-CLIMA has also applied the inversion methodology in a case study focusing on Russia to estimate fluxes of CO2 LULUCF and CH4.

EYE-CLIMA has run preliminary inversions for black carbon (BC) aerosols globally and for Europe. Considerable effort has been made to collect and harmonize BC observations from as many stations as possible. For Europe, the effect of co-optimizing the scavenging and the emissions of BC has been investigated.

EYE-CLIMA is supporting the CAMS CO2MVS through developments to ECMWF’s operational IFS 4D-Var data assimilation system. In this reporting period, EYE-CLIMA has developed the optimization of CH4 emissions within the IFS 4D-Var system using observations from GOSAT, IASI and TROPOMI.

EYE-CLIMA has prepared a first draft of a good practice guidelines for atmospheric inversions, focusing on inversions at regional scales, which are most suited for estimating emissions at national level.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The software “HiFi” has been developed for retrieving CH4 column mixing ratios from publicly available multispectral instruments, such as from PRISMA, EnMAP and EMIT. With the HiFi software, we have been able to detect emission rates as low as 0.35 tons/hour and have detected around 14 point emission locations in Europe. This is a much better detection limit compared to what is possible with TROPOMI.

We have supported the development of ECMWF’s operational IFS 4DVar data assimilation system. This system simultaneously optimizes a number of meteorological variables, the atmospheric state and CH4 emissions. Emissions are optimized daily at 80 km resolution by assimilating satellite observations from three instruments (GOSAT/TANSO, METOP/IASI and S5P/TROPOMI).

Satellite-derived AGB has hitherto been susceptible to large uncertainties. We have prepared annual maps of AGB for Europe using Vegetation Optical Depth from the L-band of the SMOS satellite (L-VOD). The maps have been prepared at 25 km resolution for 2011 to 2023. The uncertainty of the calibration of L-VOD to AGB has been assessed by comparing with national AGB stocks from national forest inventories (NFI).

We have developed a new protocol for CO2 inversions for LULUCF to enhance the use of prior flux information and to account for lateral carbon transfers. Using this new protocol results in a decrease of the land carbon sink over Europe compared to conventional inversion protocols.