Industrial emissions
As the first European satellite mission specifically designed to characterise greenhouse gas fluxes at the Earth’s surface, MicroCarb is intended not simply to observe global trends, but to resolve localised variations in CO₂ linked to cities, ecosystems and human activity.
The mission is a joint effort between the UK Space Agency and CNES, and it positions Europe as a core contributor to the international greenhouse gas observing system that underpins climate science, emissions monitoring and policy accountability.
Until recently, most satellite-based CO₂ observations have focused on broad spatial patterns and long-term global averages. While these datasets are essential for understanding climate change at planetary scale, they are less effective at attributing emissions and uptake to specific regions or sectors.
MicroCarb is designed to close this gap. By measuring atmospheric CO₂ concentrations with an accuracy of around 1 part per million (approximately 0.25%), the satellite can detect small geographical fluctuations that indicate where carbon is being emitted and where it is being absorbed.
This enables more precise identification of local sources, such as urban and industrial areas, alongside natural sinks including forests and oceans.
For environmental monitoring professionals, this represents a move towards spatially resolved carbon intelligence rather than purely trend-based analysis.
Operating in a sun-synchronous orbit at around 650 km altitude, MicroCarb will observe the same location at the same time of day, repeating its measurements on a 21-day cycle. This consistent temporal sampling is critical for separating genuine emission signals from daily or seasonal variability.
At the heart of the mission is an infrared spectrometer that measures CO₂ and oxygen concentrations across four spectral bands using sunlight reflected from the Earth’s surface.
Under standard operation, MicroCarb delivers a nominal ground pixel size of approximately 4.5 × 9 km. For targeted applications, it also includes a higher-resolution “city-scanning” mode, capable of resolving areas as small as 2 × 2 km.
This higher-resolution mode is particularly relevant for urban emissions monitoring, enabling clearer observation of CO₂ plumes associated with large cities such as London or Paris, and supporting future integration with ground-based networks and modelling frameworks.
As scrutiny of climate data intensifies, the credibility of satellite measurements depends not only on sensor design but on demonstrable traceability and validation. In this context, the role of the National Physical Laboratory is central to the mission.
NPL provided the SI-traceable optical ground calibration facilities used to test and verify the performance of the MicroCarb instrument prior to launch, working with Airbus France as prime contractor.
This calibration underpins confidence in the absolute accuracy of the CO₂ measurements, ensuring that MicroCarb data can be meaningfully compared with other satellite missions, ground stations and atmospheric models.
Post-launch, NPL scientists are also contributing to the development of retrieval algorithms and quality metrics for the CO₂ data products, supporting reliable use of the measurements throughout the satellite’s nominal five-year mission lifetime.
MicroCarb’s data is expected to play an increasingly important role beyond academic climate research.
By improving the ability to observe emissions and uptake at national and sub-national scales, the mission supports monitoring of progress towards legally binding targets such as UK net zero commitments and the goals of the UNFCCC Paris Agreement.
For regulators, policymakers and verification bodies, this offers an additional, independent line of evidence that can complement inventories, reporting frameworks and ground-based measurements.
For environmental monitoring professionals, it highlights a growing convergence between satellite remote sensing, metrology and compliance-driven monitoring.
MicroCarb does not operate in isolation. Instead, it is designed to complement existing CO₂ missions led by the United States and Japan, strengthening the resilience and coverage of the global greenhouse gas observing network.
UK organisations play a substantial role across the mission, contributing to satellite integration and testing, instrument development and scientific exploitation.
Alongside NPL and the UK Space Agency, partners include the National Centre for Earth Observation, the University of Edinburgh, the University of Leicester, RAL Space, GMV and Thales Alenia Space.
Taken together, MicroCarb represents a step change in Europe’s capacity to measure carbon with the precision needed for both science and policy.
For the environmental monitoring community, it signals a future in which satellite data becomes increasingly actionable, locally relevant and directly linked to emissions accountability.
IET 36.3 May
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