Large uncertainty in future warming due to aerosol forcing

The degree to which aerosols influence surface temperatures is not well understood. Here, the authors argue that reducing the uncertainties in the climate response to aerosol forcing is one of the key challenges to reduce overall uncertainties of warming projections. 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.

Automated summary

The degree of influence aerosols have on surface temperatures is still not clear. Reducing uncertainties in climate response to aerosol forcing is identified as a key challenge in reducing overall uncertainties in warming projections.