Khan Academy Static

For most of the past 10,000 years or so, the biosphere has been a fairly stable and predictable place. Whether you look at temperature, types of vegetation, soils, or sea level, the basic characteristics of the biosphere have remained about the same, having shown only moderate variation at any point within most of that time frame. That type of consistency is what prompted geologists to label the last 10,000 years of geological history as the Holocene Epoch; an epoch that was ushered in at the end of the last ice age. But there are now a number of scientists who view the data from the last 250 years and conclude that the biosphere is showing fundamentally different characteristics from the previous 10,000 years. The rise of carbon dioxide levels, glacial melting, and the shrinking of tropical rainforests are just some of the factors that they cite as evidence that the biosphere has entered a new epoch. Because so much of the change they have identified seems to derive from human activity, these scientists propose that this new epoch be called the Anthropocene to reflect the tremendous impact that humans now exert in the biosphere.