THE CASE FOR A CARBON REPOSITORY The current geological era is called the Holocene, sometimes referred to as the Anthropocene in recognition of the dominance of human civilization and the widespread effects of human activities on the planet across ecosystems. It is a historically warm period following the retreat of the glaciers approximately 19,000 years ago. The era has seen continuous reductions in ice coverage, with a commensurate increase in sea levels, which have been rising at a fairly regular rate over the past 5,000 years, according to the Island Institute. However, recent studies and expanded global temperature measurement suggest that portions of the planet’s surface and atmosphere are warming at a rate above what would be expected under normal [statistical] variation. As our human civilization has grown, our activities have produced greater and greater quantities of carbon dioxide and other greenhouse gases. During the industrial revolution, carbon dioxide production grew exponentially as the western nations transitioned from renewable woodbased fuels to high-carbon ‘fossil’ fuels such as coal, oil (petroleum), and natural gas. In the 20th century, the use of these fuels has grown geometrically as coal and natural gas as sources for electrification and petroleum-based transportation has expanded in the developing world.
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