13 September 2022
United in Science provides an overview of the most recent science related to climate change, impacts and responses from the World Meteorological Organization (WMO) and partner organizations. At a time when urgent action to address climate change is needed, the report provides unified scientific information to inform decision-makers and highlights some of the physical and socioeconomic impacts of the current and projected climate. Key messages: Atmospheric greenhouse gas (GHG) concentrations continue to rise and fossil fuel emissions are now above pre-pandemic levels after a temporary drop due to lockdowns associated with the COVID-19 pandemic in 2020 and 2021 • Recent years saw record high temperatures and ocean heat. Looking forward, there is a 48% chance that, during at least one year in the next five years, annual mean temperature will temporarily be 1.5 °C higher than in 1850-1900 • Mitigation pledges are insufficient to achieve the Paris Agreement. Enhanced action is needed to prevent the continued warming that is increasing the likelihood of irreversible changes in the climate system, known as tipping points • Billions of people around the world are exposed to climate change impacts. Cities – responsible for up to 70% of human-caused emissions – will face increasing socioeconomic impacts and the world’s most vulnerable populations will suffer most, as seen in recent extreme weather events • Adaptation is crucial to lower the risks to climate impacts. Early warning systems can save lives, reduce losses and damages, contribute to disaster risk reduction and support climate change adaptation.