How cool are trees?

New research from UBoC scientists indicates that molecules emitted by plants may be having a cooling effect on the planet.

acp_paper_2014_copycrop Trees take in carbon dioxide, and give out oxygen – but they also emit other, highly reactive, gases into the air (such as monoterpenes). These gases react with other compounds, like ozone, forming more complicated molecules which are able to stick onto particles in the atmosphere, helping them to grow larger. This is important because particles have to reach a certain size before they are able to interact with sunlight in the atmosphere or form cloud droplets.

The more cloud droplets there are in a cloud, the brighter it appears and the more incoming sunlight it will reflect. So, it’s important to know how many particles there are in the atmosphere that are capable of becoming cloud droplets, where they are coming from, and how this might change in the future.

In the new study, published this week in Atmospheric Chemistry and Physics (available without subscription), we used a global computer model to simulate the effect of these natural compounds on the number and size of particles in the atmosphere. We found that because these natural compounds increase the size of particles in the atmosphere, and the number of particles able to form cloud droplets, more sunlight is reflected away from the Earth’s surface when they are present.

You can find out more about the research that UBoC’s scientists are involved in here.

Cat Scott – January 2014