the global dimming trend reversed around 1990 - 15 years after the global warming trend began in the mid 1970's.
the global dimming trend reversed around 1990 - 15 years after the global warming trend began in the mid 1970's.
global dimming:44
a 2007 nasa sponsored satellite-based study sheds light on the puzzling observations by other scientists that the amount of sunlight reaching earth's surface had been steadily declining in recent decades, began to reverse around 1990.