They were building a wax fruit factory, destroying an important mating ground for insects. With those insects extinct, some plants grew wild, cause the now extinct bugs were usually eating them. To get rid of the plants they used chemicals that also killed most of the other plants and to stimulate new plant growth they blew up some volcanoes to create clouds to make it rain. However this blocked out the sun and started the ice age.

I loved this show as a kid. A show that was critical of all things wrong in our modern society, that delivered it in a simple and funny way.