When factories mass produce something it produces smoke. That smoke can be harmful to something called the ozone layer. The ozone layer is part of earth's atmosphere that protects us from the suns burning heat. When that layer is damaged the sun's heat burns through heating up the world and melting ice causing the water levels to rise. All of this can make working conditions less safe, cause more flooding, and have the sun cause cancer.
The melting of the chocolate pieces one by one showed that it was caused by heat flowing through the foil bridge. The transfer of heat happened between the foil bridge and the chocolate pieces because they were touching each other.
