ScienceDaily: Nobody knows what our skies looked like before fossil fuel burning began; today, about half the cloud droplets in Northern Hemisphere skies formed around particles of pollution. Cloudy skies help regulate our planet's climate, and yet the answers to many fundamental questions about cloud formation remain hazy. New research led by the University of Washington and the Pacific Northwest National Laboratory suggest tiny ocean life in vast stretches of the Southern Ocean play a significant role in generating...