Improved knowledge of clouds, aerosols, and their interactions is essential for better predictions of weather and climate. Aerosols (particles such as sea salt, dust, and other matter) can warm/cool the planet by reflecting/absorbing sunlight and altering cloud properties. Both the role of aerosols in climate and the way clouds respond to their presence remain major uncertainties in projections. This limits our ability to predict how global and regional climates, including extremes, will respond to rising greenhouse gases and how aerosols/clouds drive feedbacks.
Reducing these uncertainties is essential for reliable projections and weather prediction, supporting EU policy goals under the Green Deal, the EU Climate Law, and the Paris Agreement. CERTAINTY addresses this by combining Europe’s world-leading infrastructures, coordinated observation networks, and new satellite missions (EarthCARE, MetOp-SG) with advanced algorithms, machine learning, data assimilation, high-resolution and regional models, and state-of-the-art Earth system models.
The project targets key processes controlling aerosols, clouds, and their radiative effects—from warm and cold cloud microphysics to the aerosol lifecycle—across timescales from hours to decades. By integrating observation-based knowledge into models, CERTAINTY will improve understanding, enhance predictive skill, and deliver more accurate projections of climate trends and high-impact weather events.
Results will inform climate services and policy, contributing to the UN Sustainable Development Goals and supporting decisions for European citizens, industry, and governments, while keeping Europe at the forefront of climate science. This will be achieved through improved information and models of aerosols and clouds that underpin the IPCC and feed into European climate and weather services such as Copernicus.
