Associated Press: The skies are dimming, for most of the world. Increases in airborne pollution have dimmed the skies by blocking sunlight over the past 30 years, researchers report in Friday’s edition of the journal Science. While decreases in atmospheric visibility — known as global dimming — have been reported in the past, the new study compiles satellite and land-based data for a longer period than had been available. “Creation of this database is a big step forward for researching …