"Our planet's climate is a complex puzzle, and we're beginning to understand a crucial piece: the role of plants. Beyond their known task of absorbing carbon dioxide, they're also secreting volatile organic compounds (VOCs) which have a profound impact on cloud formation and, consequently, our climate," says Professor Ilona Riipinen who spearheads this work.

Professor Ilona Riipinen. Photo: Magnus Bergström/KAW

Delving into the nuanced functions of plant emissions, the research also elucidates a remarkable aspect of plant life. "Plants are not mere bystanders in our environment," Riipinen asserts. "They emit these VOCs as a defense against insects and as a means of communication. These same molecules, however, are key components in cloud formation, a critical factor in our climate system."

The role of VOCs in cloud formation

The work highlights the significant influence of clouds on Earth's temperature. Acting as a natural thermostat, clouds reflect solar radiation away from the Earth and trap heat within our atmosphere. The VOCs released by plants, upon reaching the atmosphere, react with oxidants to form aerosols—tiny particles that are essentially the seeds of clouds.

"These aerosols are more than just particles; they are the building blocks of cloud droplets, influencing their quantity and brightness," Riipinen notes. "This brightness, in turn, plays a vital role in determining how effectively clouds can reflect solar light."

Through this research, Professor Riipinen and her team are not only unveiling the hidden interactions between terrestrial ecosystems and the atmosphere but also emphasizing the critical need for comprehensive climate models to predict future climatic scenarios accurately.

Watch a video by KAW about Ilona Riipinen's work