Final answer:
The Carboniferous period is important because it left massive deposits of carbon that turned into coal. This coal provided an abundant source of energy during the Industrial Revolution and led to rapid technological progress, but also contributed to environmental degradation.
Step-by-step explanation:
The Carboniferous period is important to intelligent life on Earth because it was during this time that widespread forests of huge plants, such as club mosses, horsetails, and ferns, existed and left massive deposits of carbon that eventually turned into coal. These coal deposits provided an abundant source of energy during the Industrial Revolution and contributed to the rapid technological progress and growth of large cities. However, the use of coal has also led to the degradation of the environment and is a major contributor to global warming.