Rapidly evolving anthropogenic aerosol emissions induce strong and regionally heterogeneous climate impacts on the way to a net-zero world

Anthropogenic aerosol emissions are expected to change rapidly over the coming decades, driven by a combination of climate mitigation and air quality efforts, as well as continued industrialization. While this fact is well appreciated at the global level, the complex and diverse regional responses to changes in atmospheric aerosol loadings are still largely neglected in the tools and metrics currently used in policy-facing evaluations of near-term climate risks - including the IPCC 6th Assessment Report. 

There is now comprehensive evidence that regional changes in aerosol emissions can drive significant trends in temperature and hydroclimate, at the local to the global scale. Locally, they can dominate over trends induced by global surface warming. Notably, this is true at lower latitudes, meaning that currently under-resourced and highly populated regions are disproportionately exposed to aerosol induced climate hazards and societal impacts. Neglecting or oversimplifying regional aerosol effects, whether near to the emission sources or remotely, in near-term climate risk assessments therefore constitutes a blindspot in society’s ability to adapt to and prepare for future climate change. 

In this talk, we summarize the status of research into the regionally heterogeneous effects of aerosol emissions, in light of ongoing and expected near-term emission changes, and how they modulate climate risks along near-zero GHG trajectories. We also outline a potential pathway towards progress – in particular identifying urgently needed interaction between the aerosol research and impact, risk, and scenario development communities.