Anthropocene Sky *

We live on a smoky planet. Viewed from s;ace, the Earth is brighter than it once was, as sunlight reflects outward from a worldwide haze layer several kilometers thick. From the ground this baze makes skies that were once an intense dark blue appear milky over most of the planet's inhabited areas. The denser the population, the thicker the haze layer: One pollution plume streams out into the Atlantic from the east coast of North America, while and equivalent European plume spreads eastward into Asia. From China a thicker pall stretches across the Pacific, while smoky clouds from South Asia and southern Africa extend over the northern and southern portion of the Indian Ocean. Worldwide smoke dust, and other airborne particles released by human activity have the same combined effect as a constant medium-size volcanic eruption, scattering sulfur and soot high into the upper atmosphere. Here is another, very visible, manifestation of the Anthopocene: We have changed the color of the sky


Together, these anthropogenic airborne particles are known as "aerosols," and their impacts jointly from one of climate science's greatest unsolved puzzles. The same particles may have a warming or a cooling effect overall, depending on its elemental makeup and where it hangs in the atmosphere at any precise time. .... Page 183