Beginning in the mid 1600's earth entered into a mini-ice age. 1815 was known as the "year without a summer" and snow fell in many european countries during the summer months. the prolonged climate change is attributed to low sun spot activity, while the summer snow is believed to be the result of a) a major volcanic eruption. b) the industrial revolution. c) a growing hole in the ozone. d) major earthquakes throughout the world.