IntroductionWhen most people think of deforestation, they think of rainforest. However, this is an environmental problem that occurs worldwide. In the following pages I will delve into what exactly deforestation means and why we as a world need it, even if it has negative effects globally. Deforestation impacts our environment by reducing biodiversity, changing the water cycle, influencing soil erosion and also plays a role in the ongoing phenomenon of global warming. Since this is a global issue, the United Nations has implemented policies to help reduce the damage caused by deforestation. The UNREED policy is globally based, while the REED+ policy is nationally based. I will also explain the importance of these policies and what they mean. Understanding Deforestation Deforestation is simply the killing of trees and conditions such that trees can no longer survive where they once were. It can occur due to natural changes in climate and man's need to clear land. For example, if weather conditions occur that make a forested area cold, dry, or wet, killing all the trees and getting to the point where they can no longer survive in the area, this is natural deforestation. This type of deforestation has happened in the past. During the Pleistocene period, between 1.5 million and 10,000 years ago, glaciers melted. This melting caused sea levels to rise and wiped out forests from areas of Europe, Asia, North America, and other flooded areas. Over the last 1,000 to 100 years, several cooling and warming trends have occurred around the world. The cooling trend has caused high-altitude forests to die due to extreme cold conditions. Warming trends have caused an increase in about or...... half of the article ......uj&it=r&p=GVRL&sw=w&asid=1bed436cf422756fc559d97d44dfa507Oliver, C., Boydak, M., & Sedjo, R. ( 2008). Deforestation. In the Oxford Companion to Global Change. Oxford University Press. Retrieved October 4, 2013, from http://www.oxfordreference.comezproxy.library.astate.edu/view/10.1093/acref/9780195324884.001.0001/acref-9780195324884-e-53Sarkar, S. (2009). Habitat loss. In J. B. Callicott & R. Frodeman (Eds.), Encyclopedia of Environmental Ethics and Philosophy (Vol. 1, pp. 479-482). Detroit: Macmillan USA reference. Retrieved from http://go.galegroup.com/ps/i.do?id=GALE%7CCX3234100150&v=2.1&u=ar_a_arksuj&it=r&p=GVRL&sw=w&asid=cb8ba20c09be21e817858657e894942eThreats to global biodiversity. (2006, January 4). Threats to global biodiversity. Retrieved October 30, 2013, from http://www.globalchange.umich.edu/globalchange2/current/lectures/biodiversity/biodiversity.html