Climate change is progressing at the highest pace ever experienced by humans, driven primarily by a mix of anthropogenic emissions. Future scenarios show that the pace will stay high for a number of decades, and may even accelerate, but the details depend crucially on the mix of future emissions. Anthropogenic aerosols, or their precursor emissions, have a special role in the two next decades. While the warming from greenhouse gas emissions is quite well understood, and constrained, the uncertainty on aerosol levels between now and 2050 is as high as the entire emissions increase over the historical era. Also, aerosol emissions have regional effects that are markedly different to greenhouse gases, but that are not yet taken into account in climate risk assessments. 

In this talk, I will introduce the global regional climate effects of anthropogenic aerosol emissions, and show how they differ from well-mixed greenhouse gases. I will discuss the possible pathways of emissions evolution over the next 20-30 years, and show examples of work that try to constrain the resulting climate risk. This will include early results from RAMIP, a multi-model intercomparison project that is just getting started. 

Finally, I will discuss what efforts are needed to get regional aerosol effects into proper risk assessments, and into policy level advice on near-term climate change impacts on nature and society.