The role of satellite remote sensing in climate change studies

1 Observational data and model simulations are the foundations of our understanding of the climate system1. Satellite remote sensing (SRS) — which acquires information about the Earth’s surface, subsurface and atmosphere remotely from sensors on board satellites (including geodetic satellites) — is an important component of climate system observations. Since the first space observation of solar irradiance and cloud reflection was made with radiometers onboard the Vanguard-2 satellite in 19592, SRS has gradually become a leading research method in climate change studies3. The use of satellites allows the observation of states and processes of the atmosphere, land and ocean at several spatio-temporal scales. For instance, it is one of the most efficient approaches for monitoring land cover and its changes through time over a variety of spatial scales4,5. Satellite data are frequently used with climate models to simulate the dynamics of the climate system and to improve climate projections6. Satellite data also contribute significantly to the improvement of meteorological reanalysis products that are widely used for climate change research, for example, the National Center for Environmental Prediction (NCEP) reanalysis7. The Global Climate Observing System (GCOS) has listed 26 out of 50 essential climate variables (ECVs) as significantly dependent on satellite observations8. Data from SRS is also widely used for developing prevention, mitigation and adaptation measures to cope with the impact of climate change9. Despite the aforementioned contributions of SRS, there are concerns about the suitability of satellite data for monitoring and understanding climate change10. Climate change studies require observations to be calibrated/validated and consistent, and to provide adequate temporal and spatial sampling over a long period of time11. However, satellite data often contain uncertainties caused by biases in sensors and retrieval algorithms, as well as inconsistencies between continuing satellite missions with the same sensors. The use of satellite observations in climate change studies requires a clear identification of such limitations. The role of satellite remote sensing in climate change studies