High Heat

High Heat

Urban Heat Island

According to United States environmental Agency (2009) heat island is defined as an area which is urbanized and is hotter than the surrounding rural areas. According to Magazine of Technology (2009) urban heat effects is experienced when temperatures of an urban area rise beyond the temperatures of the suburban regions and even in the rural regions. According to heat Island Group of ( 2000) it has been found that in summer, the temperature of the surrounding air in the urban areas  would rise between  6 o to a about 8 oF beyond the temperatures of the surrounding rural regions. It therefore means that it is the activities taking place in the urban areas which influence the climate of those cities. These activities result into complex processes which are the influential factors in the temperature change in cities. The causes of urban heat effects include the destruction of natural vegetation because of the construction of buildings together with other infrastructures in the urban areas.  Waste heat which are released from the vehicles together with heat being released from factories and other industrial plants plus air conditioners found in these cities  are also major contributors of high temperatures in the urban areas.

Factor contributing to Urban Heat Effects

Destruction of trees and vegetation are some of the causes of urban heat effects. It has been found that trees and other vegetation contribute to cooling effects of the surrounding. The removal of soil and replacement of pavement has great contribution. Soil do not absorbs and retain much heat. It provides natural cooling effect therefore reduces heating of the atmospheric air surrounding the environment (Larry, 2009). Pavements that are being constructed in the cities to replace soil which provide nature cooling affect is also another cause because of their high heat absorption and retention (Roy, 2007).

According to Michael (2004) it may be the human beings themselves that cause the urban heat effect because in the previous century only two percent of the total population was in the urban regions but currently there are about twenty five percent of the total populations in the whole world who are residing in towns and cities. In the developed countries with vast industrialized capacity, more than fifty percent of the population lives in town. The migration of people from rural area to urban centre is a factor leading to urban heat island. The development of these cities in terms of industries and infrastructures are also contributors. According to Kalnay and Cai (2003) they tried to determined the rate at which land use causes climatic change as opposed to urbanization and the result was that   land use will only contribute to a mean daily temperature increase of 0.35 o C per century which is lower as compared to temperature increase as a result of Urbanization. In United States of America it was also noted that human effect in small towns also in the suburban had a significant cause to increase in temperatures. The difference in temperature was noted to be not less than 0.1o C the United States mean temperatures and the global mean temperatures. The urbanization effects were recorded to have higher change in the temperature difference which was recorded in different periods. They found that there was global warming between 1900 to 1940, global cooling during 1940 to 1965 and another period of global worming from 1965 to 2000 (Hansen, Ruedy, Imhoff, Lawrence, Easterling, Peterson, and Carl, 2001).

According to United States environmental Agency (2009) it has been noted that a city with more than a population of one million people will experience annual mean temperature of 1o C to 3 o C higher than its surrounding whereas evening temperatures can have a difference of 12o C between temperature of the city and the rural areas surrounding it. According to Michael (2004) buildings and other materials such as concrete as well as asphalts which are found in these cities are good absorbers of heat radiation and also can store large amounts of heat in comparison to natural vegetation found in the surrounding rural regions. It is also found that there is a lot of heat being released from heating sources and machines used for air conditioning; heat also produced by the power generation plants and the transport sector are also major sources. It was also found according to Michael (2004) that industrial plants, vehicles and several heating equipments such iron boxes and cookers releases bedspread of polluting materials that covers the whole city. These materials are released together with small particles, carbon dioxide and carbon monoxide gases and water in the form of vapor among other evaporates. These are the green house gases which cause the difference in temperatures of both the urban and the surrounding rural environment. It was also found that these gases act as nuclei for condensation process which will further encourage precipitation. It therefore shows that the cities are not only hot but also experiences continuous precipitation (Michael 2004)

Effects of Urban Heat Island

When there are high temperatures in the cities, it affects the environment in two different ways. First it perpetuates the development of things like smog. This occurs when there are pollutants in the air which are subjected to higher temperatures. The smog is destructive to the environment and also is dangerous to human health (Innovation magazine, 2009).

According to Mathias, Kieran, & Paul, (2006) there is high demand for the cooling as well as air conditioning equipment resulting from urban heat Island. This will further affect the consumer through high prices of these equipments. With the increase in number of these air conditioners, there will be a lot of energy required to run these equipment which will eventually affect the quality of the surrounding air and also increases the temperature. The cost of high energy and equipment is all transferred to the consumers. According to Mathias, Kieran, & Paul, (2006) it is estimated that about fifteen percent of electric energy consumed are used to solve the consequences of urban heat island in Los Angeles. There was also effect in quality of air because of the emission of these volatile gases which are dangerous to the health of people. These gases can damage the lung and cause respiratory diseases such as Asthma.

Heat Island also affects the local weather. According to (Larry, 2009) its strength will be influenced by the topography of the particular region, the distance of the region to water masses and the existing weather and climatic condition.. It will affect the local climate by interfering with the local wind pattern and encouraging formation of clouds and fog which will eventually precipitates. It will also cause rampant lightning strikes and also the raining pattern of that locality because of the variation in temperature (Kumar, Young, Goddard, & Schubert, S., (2004).

Effects of Urban Heat Island on Global Warming

According to Chris (2006) Global Warming is defined as an increase in the temperature of the Earth's atmosphere. Global warming according to Stephen (1990) had first appearance in 1989 after which several debates followed. It has brought confusion to both the public and political class of its existence and how the green house gases contribute to it. There are several signs of global warming such as storms being experienced, there is also drought, flooding along the coast lines and the damaging of habitats. Global warming occurs when green house gases forms a layer that traps heat and sun radiation on the earth atmosphere which further increase the temperature. These green house gases include carbon IV oxide, water in vapor form, nitrous oxide and the methane gas (Protecting the home we live in, 2002).Urban heat effect relates to global warming as follows. During summer, there is high energy consumption. This will cause larger emission of carbon and its compounds in the atmosphere from power generating plant which is a contributor to global warming as far as scientist are concerned. There is also the change of strategy in which people shift from tackling issues of global warming and concentrates in urban heat island (How stuff works, 2009)

Urban Heat Island can cause global warming. According to Larry, About.com (2009) in summer periods a greater number of population will be using air conditioners and refrigerators. These machines releases these green house gasses into the atmosphere which further form thick blanket that traps the heat in the earth causing rise in temperature (Pielke Sr, and Coauthors 2002),.

There is also an argument that urban heat island do not contribute to Global warming. According to John (2009) record show that two third of data being collected in relation to global warming comes from the ocean which is not affected by urban heat effect. Those collected from the land are urban and the nearby rural data so it is not composite. This seems no too convincing because these gases can spread everywhere not only the land due to wind effects. As from the initial debate on global warming, scientists have always thought of urban heat to be a major contributor (Mart, 2009). London was the first city to be Identified having problems of urban heat and several studies have indicated it can cause rise in temperatures of both large and small cities therefore there should be no question of whether it cause global warming or not (Warwick, 2003). If warm season vegetations and trees are planted they would be significant reduction in the global warming because plants and vegetation uses some of these gases like carbon dioxide as their raw materials for certain processes like photosynthesis (William 2009).

Conclusion

Global warming is caused by green house gases which trap heat on the earth causing rise in temperature and urban heat island cause release of these green house gases therefore it is clear that global warming is also cause by urban heat island. To prevent global warming there should also be an effort in stopping urban heats.

About the Author

The author Sarah Hopkins has resume writing experience of over 5years. She holds a PHD in writing from Cambridge. She has been assisting students, professionals in writing professional resumes and cover letters capitalresumes.com

Is it dangerous to thaw frozen spinach in the microwave at a very high heat?

I just thawed some frozen spinach in the microwave at a very high heat. I've never done this before. It smelled really bad when I took it out. Is that just the normal spinach smell or did I do something really bad to the spinach?

(I plan to bake the spinach in a casserole.)

They un-thaw it in the microwave on the TV cooking shows all the time. But you just need to set the timer for a matter of seconds. You are just un-thawing it not cooking it .If you are putting it in a casserole squeeze it with your hands over the sink to get out the liquid and if you are adding to a dip that is all you need to do also.. Happy cooking---

High Heat