The greenhouse free essay sample

IntroductionThe greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the Solar radiation at the frequencies of visible light largely passes through the atmosphere to warm the planetary surface, which then emits this energy at the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection What is Green House Effect ? The name Green- house effect comes from the fact that this effect is use in horticulture for the up bringing of green plants in small house made of glass walls and glass root. We will write a custom essay sample on The greenhouse or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page The green walls and roofs of a green-house allows the sun-light to come in freely but it does not allows the long wavelength infrared radiations reflected by the soil, plants and other contents of green house to go out. These trapped intra-red rays show their heating effect due to which the temperature is raised inside the green house. Thus, even without an external supply of heat, the temperature inside a green house is found to be higher than it is outside. Thus, green house acts as a heat trap. Due to the presence of carbon dioxide, our atmosphere acts like the glass rat of an ordinary horticultural green-house. Origin of the term:The term greenhouse effect is named by analogy to greenhouses. Greenhouses are basically built with materials like glass or plastic because these materials trap the radiation from the sun and help heat the surface inside the greenhouse. Greenhouses are mostly built up in places having temperature lower than the normal, such as the places at high altitudes, thus aids the growth of the seedlings required for vegetation and also planting. Objective 1: Minimise Greenhouse Gas Emissions There is overwhelming scientific evidence that human-induced greenhouse gas emissions are responsible for increasingly unstable eather patterns, overall global warming, declining ice levels, rising sea levels and increased ocean acidification. Objective 2: Minimise Natural Resource Consumption wasteful use of natural resources creates additional environmental burdens associated with the creation of waste which must be treated or disposed of, creating additional environmental impacts. Objective 4: Minimise other adverse impacts to the environmentunless sound practices are followed, there is potential during the construction process for nuisance to surrounding neighbours which include noise and vibration, dust and pollution of waterways. Objective 5: Seek pportunities to enhance or restore to the environmentDevelopment provides an important opportunity to enhance the natural environment. This includes using the development as a lever to remediate or otherwise enhance the value of land. Objective 7: Maximise sustainabili ty research and learning opportunities As an educational institution, UTS has both a responsibility and a powerful opportunity to harness the opportunities for learning about sustainable building associated with the implementation of the City Campus Master Plan, and to promulgate these learnings within the construction industry and wider community. The Greenhouse Effect and its importance The greenhouse gases act like a blanket, preventing much of the heat reflected by the earths surface from escaping directly into space. By slowing the release of cooling radiation, these gases warm the Earths surface. While this is a natural process that is essential to life on Earth, the trouble starts when the concentration of these Greenhouse gases in the Earths atmosphere increases. The result is an increase in the Earths temperature, also known as Global Warming. Global Warming is the gradual increase of the average temperature of Earths tmosphere and oceans, which can contribute to changes in global climate patterns. Global warming in turn interferes with the Earths climatic systems, resulting in climate change. Global warming could have disastrous effects on the environment (polar ice melts, changes in amount and pattern of rainfall, sea level rise, frequent floods and droughts, hurricanes and typhoons). It would cause large-scale species extinction and have serious impacts on human lives (freshwater availability, agricultural yields, increases in the spatial and quantitative ranges of disease vectors), as well as on economic infrastructure (such as energy, transport and ndustry). What are the Greenhouse Gases? carbon Dioxide (C02) *Nitrogen Oxides (NxO) Methane(CH4) *Sulphur Hexafluoride (SF6) *Chlorofluorocarbons (CFCs) ozone (03) *Hydrofluorocarbons (HFCs) Water Vapour (H20 gas) *Perfluorocarbons (PFCs) Methodology for Enhanced Greenhouse Effect Measurement Data Because the climate change signals are subtle, i. e. , 0. 5 degree centigrade per 100 years as observed, or even the predicted temperature change of 1. to 4. 5 degree centigrade in 50 years, amounting to a maximum annual rate of change of 0. 09 degree centigrade per year, observational requirements tor the detection ot climate change nd greenhouse effects are more stringent in terms of accuracy, precision, spatial coverage, and time series. Some related issues are listed in the following: Changes in instrumentation (sensor and/or calibration) Changes in location and exposure of sensors (e. g. surface stations) Changes in the methods of observation (e. g. , ship measurements of sea surface temperatu re) Changes in computational procedures (e. g. , for mean daily temperature) Changes in satellite algorithms that derive physical or geophysical parameters from spectral information Changes in data assimilation models (physics) used to compute variables r parameters that are not directly measured (e. g. , fluxes of heat, momentum, water vapor). None of the existing observational systems were designed, implemented, or operated to directly and automatically provide our needed long-term calibrated data with global coverage for climate change studies. Furthermore, it is necessary to obtain high-frequency sampling, preferably several times per day, to gather meaningful statistics on rapid atmospheric processes, particularly those affecting clouds, radiation, and precipation. In order to meet these kind of requirements, the Earth Observing System (EOS) has been proposed. The measurement methods and data sets for some greenhouse effect related variables are stated in the following: Sea Surface Temperature Global Normalized Difference Vegetation Index (NDVI) Atmospheric Carbon Dioxide (C02) and Methane (CH4) Concertrations Surface Skin Temperature Satellite measurements of SST are based on techniques in which spaceborne infra- red and microwave radiometers detect thermally emitted radiation from the ocean surface. Determining SST from satellite data therefore requires an understanding of the processes by which electromagnetic radiation is emitted and reflected at the cean surface, and emitted and attenuated by the atmosphere. These processes can be modeled theoretically. To minimize atmospheric effects, measurements must be made at wavelengths well-defined window regions of the infra-red and microwave spectrum, where the attenuation due to atmospheric constituents is small. Under favorable atmospheric and surface conditions, simple linear algorithms may provide reasonably accurate SST retrievals from either infra-red or microwave measurements. Global vegetation mapping is important for monitoring the global climate change and greenhouse effects. In order to monitor vegetation at global and continental scales, global normalized difference vegetation index (NDVI) data has been collected from the National Oceanographic and Atmospheric Administrations (NOAA) Advanced Very High Resolution Radiometer (AVHRR). The AVHRR sensor collects observations in both the red and infrared parts of the spectrum. The red spectral measurements are sensitive to the chlorophyll content of vegetation because chlorophyll causes considerable absorption of incoming radiation, and the near infrared to the mesophyll structure ot leaves which leads to considerable retlectance. Since the tlrst s an inverse relationship and the second a direct relationship, the NDVI defined as the normalized ratio (IR-Red)/(lR+Red) has close relationships with a number of vegetation attributes, such as the photosynthetic capacity of specific vegetation types, percentage vegetation cover and green leaf biomass. Thus, the NDVI has become the most commonly used remotely sensed measure of vegetation activity. Atmospheric Carbon Dioxide (C02) and Methane (CH4) Concertrations Precise record od past and present atmospheric carbon dioxide (C02) and methane (CH4) concertrations are critical to the studies of the greenhouse effects. There are a variety of techniques to determine past levels of the atmospheric gases, including direct measurements of trapped air in polar ice cores, indirect determinations from carbon isotopis in tree rings, and measurements of carbon and oxygen isotopic changes in carbon sediments in deep-ocean cores. The modern period of measurements can be taken through air samples at the monitoring stations around the world. Surface Skin Temperature The global surface skin temperatures can be obtained from the TOVS (TIROS Operational Vertical Sounder) data set. It was generated from data obtained from the HIRS/2 (High resolution Infrared Radiation Sounder) and MSIJ (Microwave Sounding Unit) instruments. The HIRS/2 instrument measures radiation emitted by the Earth- atmosphere system in 19 regions of the infrared spectrum between 3. 7 and 15 microns. The MSU instrument makes passive microwave radiation measurements in four regions of the 50 GHz oxygen emission spectrum. In particular, the combination of HIRS/2 channels and MSU channels is useful in eliminating the effects of cloudiness on the satellite-observed infrared radiances, thus providing improved estimates of the surface skin temperature. Observing The Greenhouse Effect Across The Solar System Our planet is warming up, and experts warn that the consequences will be serious. To see precisely how the process works, scientists need as much information as possible and from many different sources. There are valuable clues out in space. ESAs missions to Venus, Mars, and Saturns moon Titan will soon provide useful information to understand how our own planets climate is regulated. The Earths climate seems to be changing much more quickly than it used to do. We are altering one of our planets natural temperature regulators the greenhouse effect. The reenhouse effect determines the flow of energy arriving at and leaving from Earth. The Suns energy heats the Earths surface and the planet radiates energy back into space. However, certain atmospheric gases trap some of the outgoing energy, retaining heat. Without this natural phenomenon, average temperatures on Earth would be 30 degrees lower than the current 15 degrees Celsius. Unfortunately, fossil- fuel combustion and deforestation release large amounts of greenhouse gases to the atmosphere, strengthening the greenhouse ettect. Global temperatures nave increased more than half a degree in the last century as a result. For a really strong greenhouse effect, we should look at Venus. Venus is similar to Earth in terms of size and mass, but its surface temperature is about 460 degrees Celsius. This is hot enough to melt lead! The Venusian atmosphere is mainly made up of carbon dioxide, a greenhouse gas. On Earth, carbon dioxide makes up only a tiny fraction of the atmosphere. However, man-made emissions have caused carbon dioxide concentrations here to increase by about 30% since pre-industrial times. Why is there so much carbon dioxide in the Venusian atmosphere? What made Venus evolve so differently from Earth? Good questions. That is precisely one of the things we want to find out says Hakan Svedhem, Project Scientist for ESAs mission Venus Express, due for launch in 2005. Is Venus a mirror that reflects how the Earth will be if global warming continues at its current speed? Venus will help us understand what happens when the greenhouse effect is really extreme. However, its not a good example of what will happen to Earth due to human activities. Life on Earth would disappear due to the extreme temperatures much before reaching even half of the concentrations of carbon dioxide on Venus! says Svedhem. As a complete contrast to Venus, there is Mars. The Red Planet displays hardly any greenhouse effect.