The sky has gone dimmer over the past 35 years
Over the past 30 years, the increase in pollution has caused skies to dim slightly over most of the world. Aerosol is the main culprit as the burning of fossil fuel blocks sunlight from reaching the earth's surface.
Research was conducted by Dickinson and Kaicun Wang from the University of Maryland. A database of 3,250 meteorological stations worldwide was collected between the time periods of 1973 to 2007. The data can now be used to compare temperature, rainfall, and cloud-cover data from the past 35 years to see the impact of aerosol has on climate change.
The dimming has been nearly worldwide. The report says that while visibility worsened only slightly in North America, it "decreased substantially over south and east Asia, South America, Australia and Africa, resulting in net global dimming over land."
Europe, however, has actually experienced brightening skies, the authors say, where visibility has increased since the mid-1980s. This is because of declines in pollution over that continent, likely because of controls on using sulfur in coal, says study co-author Robert Dickinson of the University of Texas.