Dinosaurs lived in an era of high levels of carbon dioxide.
Scientists divide the earth's history into periods of time based upon climate, dominance of certain plants and animals, and other factors of geology. One such period of time is the Jurassic Period, which occurred from approximately 200 million to 145 million years ago. This period represents the dominance of dinosaurs during a time of warm temperatures, lush plant life and high levels of carbon dioxide.
Historic Levels
The amount of carbon dioxide, or CO2, in the earth's atmosphere has fluctuated over the history of the planet, according to a chart published by the U.S. Environmental Protection Agency, or EPA, which shows the levels over the last almost 650,000 years. Scientists measure CO2 in parts per million, or ppm. As of 2006, the earth's atmosphere contains approximately 382 ppm of CO2, a number that has been rising and is the highest in the last 650,000 years. This number is historically low compared to the Jurassic Period.
Jurassic Levels
Scientists determine levels of CO2 and the climate in past eras of history by using a variety of measures, including ice core samples, tree rings and ocean sediments. Warm periods and higher levels of CO2 seem to coincide. During the Jurassic Period, the CO2 numbers were high, as would be expected by the warm temperatures and abundant plant life. High levels create a greenhouse warming effect, and plants thrive on carbon dioxide.
PPM
Estimates place the amount of carbon dioxide in the earth's atmosphere at seven times the levels prior to the industrial revolution, or around 1780. Pre-industrial levels were approximately 280 ppm, according to the EPA. That would make the Jurassic Period levels of carbon dioxide around 1,900 ppm.
Explanation
The Jurassic Period was a time of volcanic eruptions. Volcanoes send large amounts of materials into the atmosphere, including carbon dioxide. An explanation for the high levels of carbon dioxide involves numerous volcanic eruptions. These eruptions would have been much more intense and frequent than today's volcanoes. Over an extended period of time, this would explain the high levels of CO2.
Tags: Jurassic Period, carbon dioxide, carbon dioxide, earth atmosphere, high levels, levels carbon, amount carbon
