The United in Science Report, released today by the United Nations Secretary-General, includes key messages on greenhouse gas concentrations in the atmosphere, global fossil CO2 emissions, global climate in 2016–2020, the ocean and cryosphere in a changing climate, water and cryosphere, global climate in 2020–2024, emissions gap, and Earth system observations during COVID-19.
The report contains important contributions from the WCRP community — especially from the WCRP Grand Challenge on Near-Term Climate Prediction and WCRP Joint Scientific Committee Member Pierre Friedlingstein. We applaud the work of Adam Scaife, Doug Smith, and colleagues in the Global Annual to Decadal Climate Update report, which shows that "in the five-year period 2020–2024, the chance of at least one year exceeding 1.5 °C above pre-industrial levels is 24%, with a very small chance (3%) of the five-year mean exceeding this level. It is likely (~70% chance) that one or more months during the next five years will be at least 1.5 °C warmer than pre-industrial levels." Pierre was involved in the chapter on global fossil CO2 emissions, from his work on the Global Carbon Budget 2019. Congratulations to all involved.