Forecasting global warming

A discovery by Arizona State University engineers Peter Crozier and James Anderson could lead to more accurate forecasting of global warming.

After studying aerosols in the atmosphere, the researchers believe some measures used in atmospheric science are oversimplified and overlook important factors that relate to climatic warming and cooling.

Today, studies of what directly contributes to climate change have focused on carbon dioxide and other greenhouse gases.

But there are other components in the atmosphere that can contribute to warming - or cooling - including carbonaceous and sulphate particles from combustion of fossil fuels and biomass, salts from oceans and dust from deserts.

Brown carbons, a nanoscale atmospheric aerosol species from combustion processes, are the least understood of these aerosol components and are largely being ignored in broad-ranging climate computer models.

The researchers say the effect of brown carbon is complex because it both cools the Earth’s surface and warms the atmosphere and that a key to understanding their properties is to look closely at their light-scattering and light-absorbing properties.