This feature article provides a summary of study about the role of clouds in the balance. Until recently, scientists were uncertain whether clouds had an overall net cooling or heating effect on the Earth's climate. But recent studies show that, in the tropics, a "near cancellation" between shortwave cooling and longwave warming exists, which indicates that the amount of incoming radiant energy is roughly equal to the amount of outgoing radiation. However, small changes in tropical cloudiness can disrupt this precarious balance.

Researchers at NASA and the University of Maryland, Baltimore County (UMBC), studying changes in tropical precipitation patterns, have noted a higher frequency of El Niños and La Niñas over the last 21 years. In addition, when either of those events occur, the world can expect more months with unusually high or low precipitation with droughts more common than floods over land areas.