Large uncertainty in future warming due to aerosol forcing

Despite a concerted research effort and extensive observational record, uncertainty in climate sensitivity and aerosol forcing, the two largest contributions to future warming uncertainty, remains large. Here we highlight the stark disparity that different aerosol forcing can imply for future warming projections: scenarios compatible with the Paris Agreement can either easily meet the specified warming limits or risk missing them completely using plausible samples from the IPCC Sixth Assessment Report assessed uncertainty ranges.