A joint British and French satellite dedicated to monitoring atmospheric carbon dioxide, the main greenhouse gas responsible for climate change, has arrived in the UK where the assembly, integration and testing will be completed. Called MicroCarb, the mission between the UK Space Agency and the French space agency, CNES, will be the first European satellite dedicated to measuring atmospheric CO2 from all around the world – the main greenhouse gas caused by human activity. The satellite will be a timely contribution to tracking progress with reducing greenhouse gas emissions as required by the Paris Agreement. Due to launch in 2024 the instrument was built by Airbus France, with pre-flight calibration and validation conducted by the National Physical Laboratory (NPL) in Teddington, before being shipped to the UK where Thales Alenia Space will complete the satellite assembly, integration and testing at the Science and Technology Facility Council’s RAL Space test facilities on the Harwell Space Cluster, in Oxfordshire. MicroCarb’s data will contribute to global efforts to measure how much carbon is being emitted by natural processes and how much by human activities. This information will help inform decisions on tackling climate change. The UK Space Agency has invested £13.9 million in the mission.

Dr Paul Bate, Chief Executive of the UK Space Agency, said: “Over half of the critical measurements on climate change rely on satellite data and the information from MicroCarb will be hugely important. Having more accurate knowledge of how much carbon the world’s forests and oceans absorb will provide the reliable information needed to take decisions on tackling climate change. “It is an exciting moment to see the MicroCarb satellite arrive in the UK. This mission shows what can be achieved when we collaborate with international partners like CNES, bringing the best of our skills and expertise together.” Dr Sarah Beardsley, Director of STFC RAL Space, said: “Achieving Net Zero is one of the most pressing challenges we currently face, and a vital part in reaching our collective goal is to develop systems that can accurately and reliably monitor carbon emissions. “I’m incredibly proud that STFC RAL Space has played such an important role in the development of MicroCarb. The pointing and calibration system that we’ve developed for this mission will enable scientists to analyse the carbon cycle in new levels of fine detail, giving us a fuller and clearer understanding of the processes driving climate change.” Andrew Stanniland, CEO Thales Alenia Space UK, said:   “With the climate crisis at the top of the world agenda, I am proud of the fact that Thales Alenia Space is at the heart of this important collaborative mission between the space agencies of France and the UK. The fact that it will be the first satellite our Assembly, Integration and Test team in the UK has fully assembled and integrated only adds to that pride. “We all learned from an early age the effect of carbon dioxide on global warming but the fact that MicroCarb will be able to measure the effect of cities on the production of CO2 will bring a significant step forward in the battle to manage the human impact on our environment.”

The NPL is providing critical pre-launch calibration and validation hardware together with metrological input into the product quality. This calibration is key to the success of the mission and precision and trust in the GHG data the satellite will send back.

NPL CEO Dr Peter Thompson said: “To make informed decisions about climate change we need to have confidence in the systems and data we use to do so. I am delighted that NPL has played such a significant role in the early stages of the MicroCarb mission, leading on the calibration and validation with our state-of-the-art facilities, and that we will continue to be involved in the mission as it progresses by using our measurement capability to input into the downstream data.”

Experts from the National Centre for Earth Observation (NCEO), at the universities of Leicester and Edinburgh, will help develop the core data products and translate observations of atmospheric CO2 into maps that show carbon sources and sinks. MicroCarb will monitor Earth’s atmospheric CO2 from space with extreme precision and detect the changes associated with surface emissions and uptake across the world from our cities, forests and oceans. An important feature of the satellite is its special city-scanning observing mode that will allow us to map the CO2 distribution across urban areas, which are responsible for the majority of global emissions, and support efforts to reduce emissions. Data from MicroCarb will help monitor international progress in meeting the Paris Agreement climate target of limiting global surface warming to well below 2ºC of pre-industrial temperatures.

Professor Paul Palmer, UK Lead MicroCarb Scientist and NCEO Science Director, said: “Data from MicroCarb will play a crucial role in extending our current ability to verify reductions in global and national emissions of CO2 in response to the demands of the Paris Agreement. “Cities are home to half of the world’s population and are therefore at the forefront of the global challenge to reduce emissions of GHGs. The city-scan observing mode of MicroCarb, which can map out atmospheric CO2 over cities the size of London and Paris, will provide new information to help cities implement strategies that support sustainable urban development.”