New discovery in atmospheric chemistry helps predict methane’s role in climate change

The newly discovered atmospheric reaction changes methane estimates. Credit: Pixabay

In a study published in Science, scientists describe a newly discovered reaction that improves modeling of methane in the atmosphere. Modeling methane’s atmospheric lifetime is important to understanding how the potent greenhouse gas contributes to climate change. To date, models consistently overestimate the amount of hydroxyl radicals (OH), the molecules responsible for breaking down methane, in the atmosphere, leading scientists to calculate that methane will break down faster than it actually does. In the newly discovered reaction, water vapor absorbs ultraviolet light, reducing the availability of sunlight to create OH. This finding helps explain why existing models overestimate OH levels and, consequently, methane’s atmospheric breakdown rate.