The document summarizes how human civilization has progressed through different eras and their impact on the environment over time. It discusses three main eras: the Agrarian era from 11,000 BC to 1750 AD, when agriculture dominated society; the Modern era from 1750 AD to recent times, characterized by industrialization; and the current Digital era, defined by computer and internet technologies. While early human societies had a relatively low impact on the environment, the document notes that in the last 100-130 years human activities have started to negatively affect the planet.