About

Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic (“human-made”) greenhouse gases (GHG) driving global climate change.

Increasing atmospheric concentrations of these Essential Climate Variables (ECVs) leads to global warming with adverse consequences such as rising sea levels. It is therefore important to monitor the spatial distribution and the time evolution of these gases, and to improve our knowledge of their various natural and anthropogenic sources and sink.

The focus of the previous GHG-CCI project (2010-2018) was to improve retrieval algorithms needed to generate high-quality CO2 and CH4 atmospheric data products from the satellite sensors SCIAMACHY/ENVISAT, GOSAT, and IASI. Since 2018, these products are generated operationally via the Copernicus Climate Change Service and they are available via the Copernicus Climate Data Store for all interested users and free of charge.

The focus of the new GHG-CCI+ project, which started in March 2019, is to perform research and development (R&D) needed to generate new ECV CO2 and CH4 satellite-derived products, which have not been generated in the GHG-CCI pre-cursor project.

Objective

The objective of the GHG-CCI+ project is to further develop retrieval algorithms needed to generate new high quality satellite-derived CO2 and CH4 atmospheric data products. These ECV data products are column-averaged dry-air mole fractions (molecular mixing ratios) of CO2 and CH4, denoted XCO2 and XCH4, respectively. Specifically, the following products are generated:

• XCO2 products:
  • CO2_OC2_FOCA: retrieved from OCO-2 using University of Bremen’s FOCAL algorithm
  • CO2_TAN_OCFP: retrieved from TanSat using University of Leicester’s OCFP (or UoL-FP) algorithm
  • CO2_GO2_SRFP: retrieved from GOSAT-2 using SRON’s SRFP (or RemoTeC full physics) algorithm
• XCH4 products:
  • CH4_S5P_WFMD: retrieved from Sentinel-5-Precursor (S5P) using University of Bremen’s WFMD (or WFM-DOAS) algorithm
  • CH4_GO2_SRFP and CH4_GO2_SRPR: retrieved from GOSAT-2 using SRON’s RemoTeC algorithm (SRFP for the “full physics” product and SRPR for the “proxy” product)

After validation and initial user assessments, the data products are made available via the CCI Data Portal. Each year, a new data set will be released using improved algorithms and extended data coverage. The planned dates for product release are:

• Data set CRDP5:
  • Available via CCI Open Data Portal:
  • Products: CO2_OC2_FOCA, CH4_S5P_WFMD, CO2_TAN_OCFP
• Data set CRDP6:
  • Available in Feb/Mar 2021
  • Products: all (see above)
• Data set CRDP7:
  • Available in Feb/Mar 2022
  • Products: all (see above)

Video: Within ESA’s Climate Change Initiative Project, expert Michael Buchwitz, of University of Bremen in Germany, explains the importance of greenhouse gases as an ECV to understand our changing world.