Sustainability of Agriculture Essay -- Environmentalism / Economics / Ag

To define the sustainability of agriculture, we must look into the several relationships agriculture has with the basic nature of making something sustainable. In this research literature, we will look at the factual information regarding agricultural practices as they relate to the long-term stability of biodiversity, ecosystems, and Natural resources. We will also compare historical and modern perspectives of economics as they relate to resources and sustainability. The researched information will give us a better idea to propose solutions and methods for a more sustainable future-global food supply. Let us first start with the DNA of agriculture: biodiversity, ecosystems, and natural resources. Agricultural biodiversity is a subset of biodiversity as it pertains to the crop varieties. Agricultural biodiversity is an important part of modern agriculture and its sustainability because it creates a complimentary variety of plants and other organisms that increase the potential of crop survival and longevity. For example, the nodules found at the end of legumes increase the nitrogen level in the soil that may produce a higher quality crop fit for consumption. It also makes the soil last longer resulting in high-yielding crops. For example, the following information is from an article in an AridLands Newsletter at an Arizona College: â€Å"It was in this dramatic scenario that the Drylands Polyculture Project was born. It was observed that despite its apparently barren prospects, the Sertà £o is a rich and prosperous land, producing many local and adapted crops and fodder plants. The problem was not the climate-as is usually implied-but the agricultural model, based on slash-and-burn, or worswhen water is scarce and when that crop is harvested, the hydrophilic crops can be planted when the wet season returns. The benefit of a monoculture is not only the profits produced, but the amount of food that can be harvested at once and the amount of maintenance needed to care for the crop is low because the variables are few since it is only one crop using the same soil for the same amount of time during the same season every year. This is convenient and profitable, but not sustainable. Works Cited Hanzi, Marsha, â€Å"Polycultures in the Brazilian drylands: A new version of an old tradition† AridLands Newsletter, No. 48, November/December 2000 â€Å"Agricultural Ecosystems: facts and trends† brochure by the World Council for Sustainable Development and the IUCN pages 3-5, July 2008 Levetin and McMahon, â€Å"Plants and Society 5th ed† page 242, paragraphs 3-4

Descartes third meditation Essay Example | Topics and Well Written Essays - 1500 words

Descartes third meditation - Essay Example If from itself, then it is clear from what has been said that it is itself God, since if it has the power of existing through its own might, then undoubtedly it also has the power of actually possessing all the perfections of which it has an idea—that is, all the perfections which I conceive to be in God. If, on the other hand, it derives its existence from another cause, then the same question may be repeated concerning this further cause, namely whether it derives its existence from itself or from another cause, until eventually the ultimate cause is reached, and this will be God. Descartes presents two evidences of that outcome. Each piece of evidence states that an identified effect can be clarified as long as an all-powerful being is present. The effects Descartes draws on are the meditator’s idea of (1) his/her life as predetermined and (2) of God. In this manner, Descartes directs the meditator to dig up his well-known rule for unraveling the truth, which is ‘clear and distinct perceptions are true’ (Cunning 2010, 62). And, undoubtedly, a great deal of the Third Meditation focuses on whether the assumption of a misleading God, which appears to dispute the rule, can be eliminated (Wilson 2003). The application of the rule in assessing and disputing the deceiving-God assumption has encouraged a number of scholars to accuse Descartes of circular reasoning. In the Third Meditation, Descartes further claims that, fundamentally, God’s existence as his maker is a circumstance of his taking part in inquiry informed by the method of doubt. This allows him to analyze with absolute confidence that God made him, and hence that all he knows ‘clearly’ and ‘distinctly’ to be factual, is factual. God’s existence, in that case, is an external state of Descartes’s doubt (Gaukroger 2006). Apparently, God is not external with regard to taking up a space that

The Earth energy-balance Term Paper Example | Topics and Well Written Essays - 2000 words

The Earth energy-balance - Term Paper Example This phenomenon is known as earth energy budget or earth energy balance. There are many factors that can deteriorate this balance and can contribute to significant changes in the climate of the earth. Earth Atmosphere: To understand how energy is received and returned to maintain energy balance it is important to understand what constitutes the atmosphere. There are five layers that surrounds the earth; exosphere, thermosphere, mesosphere, stratosphere and troposphere. Exosphere is the most outer space with particles so far apart that they do not affect the pathway of radiations from sun. Troposphere is the innermost layer that span from the earth surface to about 10 kilometers above. This layer is important as it provides the maximum reflection of radiation as discussed below. The following diagram (fig 1) demonstrates the inner three layers of earth atmosphere. Fig 1. Inner three layers of earth’s atmosphere Incoming radiation: Radiations from sun experience no interference as they travel undisturbed in space to reach the earth’s atmosphere. In the atmosphere, there are different layers with variable densities of gases and other molecules. When these radiations collide with these molecules they are deflected in many directions, a phenomenon known as scattering. An important concept to remember here is that these radiations that reach the earth have very small wavelength and not all but a small selective proportion of electromagnetic radiations can be scattered by molecular collision. (Ahrens, 2012). The rest of energy is absorbed by the earth system in various forms. Most of the energy is absorbed by the solid earth that increases the core and surface temperature. Part of the energy is absorbed by clouds, water vapors and other molecules present in the earth atmosphere. The following diagram (fig 2) represents the overall exchange budget of earth’s energy. Figure 2. Earth’s energy balance It is evident from the diagram that the tot al incoming energy absorbed by the earth system almost equals to the energy returned back to space thus maintaining energy balance. Outgoing radiations: The radiations received from sun can be returned back to space by two basic mechanisms as explained below. Reflection: Some of the energy that enters the atmosphere is reflected back as same short wavelength radiations identical to what was received from sun. Different component of earth’s atmosphere have variable ability to reflect these radiations and this property is known as ‘albedo’. Therefore, various surfaces have variable albedo. For example, deserts have high albedo because they are able to reflect about 40% of the radiations that reach them back into the space. On the other hand, ocean surfaces and rainforests have low albedo as they are able to reflect only a small proportion of radiations. (Ahrens, 2012). It is important to understand that those surfaces that have lower albedo tend to retain heat more than those with higher reflection abilities. By looking at fig 2, it can be observed that only a part of the radiations, about 30%, are reflected back into the space by earth surface, clouds and scattering process. There should be another way of returning the remaining 70% of the radiations which were absorbed by the atmosphere and the earth. Emission: Thermic emission is the most