Acknowledgements This Technical Report was researched and principally authored by Professor Sekhar N. Kondepudi from the National University of Singapore (NUS). Vinod Ramanarayanan, Alok Jain, Guru Nandan Singh, Nitin Agarwal NK, Rahul Kumar and Rahul Singh (NUS), Pernilla Bergmark (Ericsson), Takafumi Hashitani (Fujitsu), Paolo Gemma (Huawei), Ziqin Sang (Fiberhome), Daniela Torres (Telefónica), Angelica Ospina (University of Manchester) and Mythili Menon (University of Geneva) provided inputs to this Technical Report. The author also acknowledges the guidance and support from all the members of the ITU‐T FG‐SSC Management Team. Additional information and materials relating to this Technical Report can be found at: www.itu.int/itu‐t/climatechange. If you would like to provide any additional information, please contact Cristina Bueti (ITU) at tsbsg5@itu.int.