The Earth has been around for a good 4.6 billion years. Let us compress the long time from the Earth’s birth to today (2012) into one year to put everything in perspective.
The Earth’s history starts on January 1, 00:00:00. The Earth is a hard sphere, barren as any other planet. Incessant wind and rain erode away the barren mountains and tectonic forces create new ones. Nothing much happens for the next three months. Then, around the start of April, life begins in the form of bacteria. Over the course of the next few months, the bacteria divide and mutate, slowly forming new life forms that are multicellular. However, all life on Earth are still in the oceans.
Life on land only starts in the end of November, when plants begin to settle on land. Plants expertly take the abundant carbon dioxide in the atmosphere and convert it into oxygen. By early December, the oceans are teeming with fish, some of which adapt to living on land by developing lungs. These become the first amphibians. Insects also populate the land and become one of the most diverse types of life.
In December 12, reptiles evolve and the land is ruled by dinosaurs, but only for 9 days until they are wiped off the face of the Earth by a meteorite on December 20. Mammals quickly take the niche left by dinosaurs, populating the entire world. Even at this late time, there are no signs of humans.
December 31, humans have still not arrived on Earth. They only appear around 8pm, where the first hominids venture on to the plains of Africa. At 10pm, the Ice Age begins and the Earth is covered by a thick white sheet of ice. The ice comes and goes three more times. At 11:59pm, human civilisation begins as cities begin to rise. 22 seconds before the end of the year, the Egyptians build their pyramids. More monuments arise within seconds. At 11:59:47pm, Jesus teaches the people to love one another, until he is killed a millisecond later. In the last second of the year (about 150 years), humanity: has two major world wars, take to the skies, create the nuclear bomb that can wipe out all life on Earth and even step foot on the Moon.
We may like to think that we have made a significant impact in the history of the Earth, but we have only existed for an infinitesimally small fraction of the history. We are but a dot on the grand scheme of natural history.