GUIDED BY Mr. A V AJITH LECTURER OF CIVIL ENGINEERING PRESENTED BY SAJITH E R S7 CIVIL ROLL NO: 46

INTRODUCTION:  Global warming is defined as the overall warming of the planet, based on average temperature over the entire surface.  Modern technology is based up on a number of manufacturing units exploiting the natural resources.  Due to rapid industrialization and fast population growth we are suffering from an unwanted danger of enviournment problem.  Science has given us atomic energy, comfortable communication systems etc.. for the betterment of the society but at the same time the life has become uncomfortable and tenseful due to the presence of same devices. The pollution is accompanied by the gradual rise in global atmospheric temperature, which is known as global warming.  This study deals with Global warming effects and methods to prevent it.

GLOBAL WARMING  An overall warming of the planet, based on average temperature over the entire surface.  Carbon dioxide is the key factor in causing Global warming.  The indiscriminate burning of the fossil fuels like coal, oil and natural gases, releases huge quantities of gases into atmosphere.  The industrialized nations have emitted gaseous pollutants more than the developing nations.  The fact that the current decade is the hottest period of the century is an indication that the globe is warming up.  This will lead to significant adverse effects on the world’s natural system and human population over the next century.

Graphical representation of Global warming

GREEN HOUSE EFFECT  A secular increase in the carbon dioxide in the atmosphere, arising from progressive industrialization and the combustion of fossil fuels, could rise the mean temperature of the atmosphere, effecting profound climatic changes.  The important fact is that- Short Wave Radiation can pass easily to the atmosphere through the surface of the earth, while a portion of the resultant heat is retained in the atmosphere. Since outgoing long wave radiation cannot penetrate the atmosphere as easily, especially when there is cloud covers the gases, it leads to an enhanced heat-trapping of the earth. This heat-trapping capacity of the atmosphere is called ‘Green House Effect’.  Accoding to the principle of infrared absorption characteristics of gases. Higher the concentration of green house gases, greater will be the absorption of thermal radiations.  There are certain negative effects like melting of (glaciers,mountain snow caps,land based ice sheets),increase in diseases,extinction of higher level species and lowered agricultural productivity.

The atmosphere radiates energy to space and back to the earth

Green House Gases The main green house gases are  Carbon dioxide(CO2)  Methane(CH4)  Nitrous oxides  Chlorofluorocarbons(CFCs)  Ozone  Carbon dioxide is the key factor in causing green house effect. The indiscriminate burning of the fossil fuels like coal, oil and natural gases, releases huge quantities of gases into atmosphere

Human activities contribute for Global warming

Effects of Global warming EFFECT OF GLOBAL WARMING ON: CLIMATE EFFECT OF GLOBAL WARMING ON: SEA LEVEL EFFECT OF GLOBAL WARMING ON: WATER RESOURCES EFFECTS OF GLOBAL WARMING ON: VEGITATION EFFECTS OF GLOBAL WARMING ON: HUMAN HEALTH EFFECTS OF GLOBAL WARMING ON: HUMAN SETTLEMENTS AND SOCIETY EFFECTS OF GLOBAL WARMING ON: ENERGY EFFECTS OF GLOBAL WARMING ON: CLOUDS AND WATER VAPOUR EFFECTS OF GLOBAL WARMING ON: AGRICULTURE EFFECTS OF GLOBAL WARMING ON:WILD LIFE

Climatic changes Climate change is now becoming one of the major global environmental challenges About 80% of greenhouse gas emissions from human activities are related to the production and use of energy- and particularly the burning of fossil fuels. The bulk of the remaining 20% is associated with agriculture and changes in land use. There is an increase in the average temperature of the earth’s surface, leading to wide spread impacts ranging from change in rainfall patterns to extinction of certain species.

Ice ages Records of past climates have been used to show what the climate was like during the last several hundred thousand years. These records have demonstrated that the global climate has changed from being fairly warm, as it is now, to being very cold. These cold periods are known as the Ice Ages, and the last one affected the Earth only 18,000 years ago. The change in global climate between Ice Ages and warm periods is linked to the Earth's changing orbit around the Sun.

Climate models Climate models are special computer programmes. have attempted to show man-made influences on climate change. Firstly, climate models are used to gain a clearer picture of past climates. If a good match is found between the model results and the real observations, the model is believed to be working well, and it can then be used to predict future changes in climate. All climate models, however, are subject to a lot of uncertainty, and their predictions should not be considered to be fool proof, but as intelligent estimations based on existing knowledge.

Prevention of Global warming Most energy is produced by the burning offossil fuels, like coal, oil and gas, which release carbon dioxide, a greenhouse gas.. To prevent this we have to organize self-awareness programmes, planning exhibitions in different parts of the countries to create awareness. BY RECYCLING BY ROAD TRANSPORT BY RENEWABLE ENERGY THE FRAMEWORK CONVENTION ON CLIMATE CHANGE

Conclusion Global warming is the product of green house effect. This global warming is predicted to lead a variety of negative effects, to reduce this we need to develops steps for the prevention such as organizing self awareness programmes, planning exhibitions in different parts of the countries to create awareness on global warming. Apart from the plans to slow down the global warming, adaptation schemes must move forward fast. Constructing flood defences, banning buildings close to sea areas are some of the measures we can adapt

References M.N. Rao and H.V.N. Rao. Air Pollution (2005) Arvind Kumar and Manish C. Varma.Environmental Pollution and Health Hazards, A.P.H. Publications, Page: 273 Iyyanki.V. MuraliKrishna and ValliManikam. Global Climatic Changes and Weather Modification Technologies. Hyderabad, B.S. Publications, Page: 455 By Dr. M.H. Fulekar [May–March 2007].Environmental Science and Engineering