Proceedings of the International Conference on Radioscience Equatorial Atmospheric Science and Environment and Humanosphere Science 2021 1. Reducing Sugars Production from Oil Palm Empty Fruit Bunches (OPEFB) by Combined Dilute Acids Hydrothermal Pretreatment 2. The decline of surface global solar radiation at Palembang City of Indonesia correlated to the smoke events in 2019 3. Atmospheric Response to the Southern Java Upwelling Variability Associated with Positive Indian Ocean Dipole Event 4. Technological Properties of Formaldehyde Free Adhesives based on Oxidized Starch Mixed with Different Crosslinkers for Plywood 5. Characteristic of Precipitable water vapor in 2017 2019 over Bandung estimated by GPS data 6. Convectively Coupled Equatorial Waves (CCEWs) Triggering Torrential Rainfall Events over Sumatra Indonesia 7. Kelvin Wave Activity in the UTLS over the Maritime Continent from GPS RO Measurements 8. The Influence of the QBO on the MJO Related Rainfall Variability over the Maritime Continent 9. Water Quality Assessment for Detecting Submarine Groundwater Discharge (SGD) Pollution in The Coastal Area of Krakas Beach North Lombok District Indonesia 10. The Influence of Boreal Summer Madden Julian Oscillation on Precipitation Extremes in Indonesia. This book presents recent advances in the area of Radioscience Equatorial Atmospheric Science and Environment from the international symposium for equatorial atmosphere of the celebration of the Equatorial Atmosphere Radar (EAR) 20th Anniversary conducted by Indonesian National Institute of Aeronautics and Space (LAPAN) and Kyoto University in 2021. It provides a scientific platform for all participants to discuss ideas and current issues as well as to design solutions in the areas of atmospheric science environmental science space science and related fields.