Global Warming Essay -- Environment, Climate Change

How much global warming we are going to see from extra CO2 depends on how sensitive the climate system is. David C Frank, Jan Esper, Christoph C Raible, Ulf Bà ¼ntgen, Valerie Trouet and Benjamin Stocker have published a study to improve the estimations of the carbon cycle sensitivity to climate and climate projections for the future. The carbon cycle sensitivity-which is important for global warming projections-to climate is the increase or decrease of atmospheric CO2 concentrations which lead to an increase or decrease in temperature6. As we can observe from different estimations, the increase or decrease of carbon concentrations in the atmosphere have changed during the past millennium6.There were certain periods where the temperatures were low (Little Ice Age) and other periods where the temperatures were higher (Medieval Warm Period)6. The present geological period is the Holocene which began approximately 10000 years ago4. Even though the geological period is the same since mo re than 10000 years ago, many climatic variations have occurred. For example, the Little Ice Age is the period between 16th century and 19th century, being 1601-1630 the coldest of the past millennium6.In the opposite side we find that the warmest pre-instrumental period was during the Medieval Warm Period, and more precisely, between the years 1071-11006. Moreover the warmest instrumental period (with records back to 1850) was the period 1971-20006.There are many factors that influence the climate variability. These factors can be classified as internal or external to the climate system. Examples of external influence are anthropogenic activities and natural influences (e.g. volcanic activity) 11. Anthropogenic influence on CO2 variations in pre-industr... ...g Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change [Houghton, J.T., et al. (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 349–416. 15. Raupach, Michael R & Canadell, Josep G, 2010: Carbon and the Anthrpocene. Current Opinion in Environmental Sustainability. 2: 210-218. 16. Raupach, Michael R, Canadell, Josep G, Le Quà ©rà ©, Corinne. Anthropogenic and biophysical contributions to increasing atmospheric CO2 growth rate and airborne fraction. Biogeosciences 5: 1601-1613 (2008). 17. Richard Alley et al., 2007: Climate Change 2007: The Physical Science Basis. Intergovernmental Panel on Climate Change. 10th Session of Working Group I of the IPCC, Paris, February 2007. 18. Ruddiman W F (2003). The anthropogenic greenhouse era began thousands of years ago. Climatic Change 61: 261–293.