Air quality and climate

The challenge

Increasing anthropogenic emissions are affecting air quality and contributing to climate change. We need to understand the chemistry of the atmosphere to be able to predict the impact of this with confidence and to enable us to prevent and mitigate further changes. Global greenhouse gas emissions due to human activities have grown since pre-industrial times, with an increase of 70 per cent between 1970 and 2004. World CO₂ emissions are expected to increase by 1.8 per cent annually between 2004 and 2030.104 Increasing anthropogenic emissions are affecting air quality and contributing to climate change. Scientists have an important role to play in understanding the chemistry of the atmosphere to be able to predict with confidence the impact of these emissions and to prevent and mitigate further changes. To achieve this, the chemical sciences will need to:

• develop novel techniques for studying reactive molecules that occur at ultra-low concentrations in the atmosphere and are the agents of chemical change;
• understand, through developing novel techniques for studying sub-micron particles, how aerosols form and change in the atmosphere, and their impacts on human health and climate;
• study geo-engineering solutions to climate change – such as ocean fertilisation to draw down CO₂, or increasing the Earth’s albedo by enhancing stratospheric aerosols to modify the Earth’s climate in response to rising greenhouse gas levels – looking both at the effectiveness and undesirable environmental side-effects of these solutions;
• develop new modelling methodologies for treating the enormous chemical complexity that occurs on regional and global scales.

This must be coupled with developing novel analytical techniques, such as low-cost sensors for the detecting of atmospheric pollutants (ozone, nitrogen oxides, particulates etc), which can be dispersed throughout both developed and developing urban areas for fine-scale measurement of air quality, and can be used in developing atmospheric models. In addition, technology breakthroughs will be required in space-borne techniques for measuring major pollutants, including particulate aerosols, with sub-20 km horizontal resolution and the capacity to resolve vertically within the lower troposphere.