National Geographic : 1976 Nov
NATIONALGEOGRAPHICPHOTOGRAPHER JAMESL. STANFIELD(ABOVE);MICROGRAPHBY ROGERJ. CHENG, STATEUNIVERSITYOF NEWYORKAT ALBANY(BELOW);GODDARDSPACEFLIGHTCENTER,NASA Progress casts a pall over a heavy industry complex in the U. S. Northwest, where smokestack effluvium dims the morning sun (above). To the possible climatic influences of reflective ice and volcanic dust veils must now be added the influences of the human volcano. Commercial smoke, jet exhaust, city smog-all have become an unknown factor in the planet's future climate. A view from above reveals how man made clouds already affect present-day weather (right). In mosaic Landsat images, long plumes of pollution sweep ing northeast from Chicago and Gary, Indiana, breed snow that falls on Lake Michigan's eastern shore. An electron micrograph shows how it happens (left): Ice crystals form around lead particles from an automobile's exhaust.