How did humans first alter global climate?

• Autores: William E. Ruddiman
• Localización: Scientific American, ISSN 0036-8733, Vol. 292, Nº. 3, 2005, págs. 46-53
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Dialnet Métricas: 2 Citas
• Resumen

  • The article discusses the history of man's influence on the global climate. The scientific consensus that human actions first began to have a warming effect on the earth's climate within the past century has become part of the public perception as well. Now, though, it seems our ancient agrarian ancestors may have begun adding carbon dioxide (CO2) gases to the atmosphere many millennia ago, thereby altering the earth's climate long before anyone thought. New evidence suggests that concentrations of CO2 started rising about 8,000 years ago. Some 3,000 years later the same thing happened to methane, another heat-trapping gas. Human activities tied to farming--primarily agricultural deforestation and crop irrigation--must have added the extra CO2 and methane to the atmosphere. These activities explained both the reversals in gas trends and the ongoing increases right up to the start of the industrial era. Since then, modern technological innovations have brought about even faster rises in greenhouse gas concentrations. Cores of ice drilled in the Antarctic and Greenland ice sheets have provided extremely valuable evidence about the earth's past climate, including changes in the concentrations of the greenhouse gases. INSETS: Overview/Early Global Warming;Human Disease and Global Cooling.