Professor Martin Williams discusses several issues related to future air quality in the UK and Europe. He outlines challenges in meeting commitments in the UK Clean Air Strategy and uncertainties around the effectiveness of clean air zones and real-world vehicle emissions. Williams also notes potential antagonisms between climate change policies aimed at reducing CO2 and air quality if measures like increased biomass burning are not properly managed. He summarizes upcoming changes to WHO air quality guidelines and uncertainties following Brexit regarding environmental regulations and oversight.