| O'Neill, Christopher C. | Ulster University, United Kingdom | P.5.2 Presenter |
| O'Neill, Christopher | Ulster University, United Kingdom | P.5.2 |
| Ogutu, Booker | School of Geography and Environmental Science, University of Southampton, Southampton, UK | S.4.3, P.4.2 |
| Origo, Niall | Earth Observation, Climate and Optical group, National Physical Laboratory, Hampton Road, Teddington, UK | S.4.3 |
| Orlandi, Diana | Department of Information Engineering, University of Pisa, Pisa, Italy | S.5.5 |
| Ouyang, Xijun | China Three Gorges University, College of Hydraulic and Environmental Engineering, Yichang 443002, China | P.1.2 |
| Owda, Abdalmenem | Technical University of Denmark, Denmark | S.2.1 |