The Atlantic: The Arctic Has a Cloud Problem. Tiny iodine particles are clumping together to trap sunlight and melt polar sea ice.
To climate scientists, clouds are powerful, pillowy paradoxes. They can reflect away the sun’s heat but also trap it in the atmosphere; they can be products of warming temperatures but can also amplify their effects. Now, while studying the atmospheric chemistry that produces clouds, researchers have uncovered an unexpectedly potent natural process that seeds their growth. And as the Earth continues to warm from rising levels of greenhouse gases, this process could be a major new mechanism for accelerating the loss of sea ice at the poles—one that no global climate model currently incorporates.
This discovery emerged from studies of aerosols: the tiny particles suspended in air onto which water vapor condenses to form clouds. As described this month in a paper in Science, researchers have identified a powerful yet overlooked source of cloud-making aerosols in pristine, remote environments: iodine.