Environmental Science Test 3 Study Guide Energy sources and consumption o Industrialized countries Smaller percentage of the total population Larger user of total energy produced o Example US Only 5 of the worlds population uses about 25 of the total Energy consumption in the us today energy consumed o Look at the generalized energy flow of the us for a particular year We imported considerable more oil than we produced Consumption distributed in3 sectors Residential commercial Transpiration Industrial o We remain dangerously venerable Energy conservation increased efficiency and cogeneration o Conservation of energy Using less energy Adjusting our needs and uses to minimize the amount of high quality energy necessary for a given task o Increased energy efficiency Designed equipment to yield more energy output from a given amount of input energy first law efficiency Better matches between energy source and end use second law efficiency o Cogeneration Processes designed to capture and use waste heat meaning no thermal pollution Captured waste heat increases overall efficiency of a typical power plant from 33 to 75 Could provide about 10 of the power capacity of the us Automobile design o Electric or hybrid vehicles have better mpg o Improvements has several sauces Increased efficiency and resulting conservation of fuel Cars that are smaller engines constructed of lighter materials Issues problems Exam 3 Terms o Silent Spring a book written by Rachel Carson about the detrimental effects of pesticides DDT on the environment particularly on birds DDT most powerful pesticide the world has ever known which exposed nature s venerability It is capable of killing hundreds of different types of insects at once while other pesticides can only kill one or two Malaria an infectious disease caused by one of several species of protists in the genus Plasmodium DDT was used in the 1939 to kill malaria causing insects Energy o KE Kinetic energy the energy of motion o PE potential energy which is stored energy that has not been released o Sources and origins the sun is the ultimate source of almost all types of energy It fuels photosynthesis solar energy heating of the atmosphere and ground heating Wind biomass which is natural products such as wood dams rivers and energy from the earths crust are all more sources of energy 40 of us energy from all sources is used to generate electricity 85 of the energy used in the US is provided by fossil fules 20 of our electricity is generated by nuclear fuel 7 of our total energy comes from renewable energy sources such as wind solar and hydropower o Quality the ease with which an energy source can be used for work The ability of the energy to do work Higher quality of the energy more easily converted to work Lower energy quality more difficult to convert to work o 2nd Law of Thermo energy always tends to go from a more useable higher quality form to a less usable lower quality form So when you use energy you lower its quality o 2nd Efficiency Law refers to how well matched the energy end is with the quality of the energy source o 1st Efficiency Law deals with the amount of energy without any consideration of the quality or availability of the energy o EROI Energy Return on Energy Invested o Sun Earth radiation Solar radiation reaches Earth with more than enough energy in a single square meter to illuminate five 60 watt lightbulbs if all the sunlight could be captured and converted to electricity o Greenhouse Gases a gas in earth s atmosphere that traps heat near the surface o Relative Absorption o CO2 levels CO2 is an important greenhouse gas that can contribute to global warming Although CO2 concentrations vary between seasons there is a clear trend of rising CO2 concentrations across the years This increase over time is correlated to increased fossil fuels and net destruction of vegetation o Temperature the measure of the average kinetic energy of a substance Measurements although annual mean temperatures can vary from year to year temperatures have exhibited a slow increase from 1880 to today This pattern becomes much clearer when scientists compute the average temperature each year for the past 5 years Proxies provides a means for scientists to determine climatic patterns before record keeping began Examples of proxies include ice cores tree rings sub fossil pollen boreholes corals lake and ocean sediments and carbonate speleothems Changes Climate Change IPCC a group of more than 3000 scientists from around the world working together to assess climate change Their mission is to understand the details of global warming system the effects of climate change of biodiversity and energy fluxes in ecosystems and the economic and social effects of climate change IPCC hypothesis Emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases CO2 methane CFCs and nitrous oxide These increases will enhance the greenhouse effect resulting on average in an additional warming of the Earth s surface of about 0 3 oC per decade o Urban Heat Island Effect metropolitan area that is significantly warmer than its surrounding rural areas due to human activities o Empirical Evidence is a source of knowledge acquired by means of observation or experimentation o Past Current Temp Trends some regions have become cooler and some regions have had no temperature change and the northern latitudes have became substantially warmer o Hurricanes warming of the ocean does appear to have increased the intensity of hurricanes Hurricanes such as Katrina and Rita appear to have become as powerful as they did because waters in the gulf of Mexico were unusually warm and scientists concluded that climate change was responsible for at least half of this warming o Volcanoes eruptions can add a significant amount of carbon dioxide to the atmosphere and other gases that are released have important short term climatic effects The ashes emitted in the atmosphere have a major effect on global temperatures by reflecting incoming solar radiation back out into space thereby cooing the earth o El Nino the periodic changes in winds and ocean currents causing cooler and wen the southeastern US and unusually dry weather in southern Africa and southeast Asia o Albedo the percentage of incoming sunlight reflected from a surface o Milankovich Cycles refer to long term variations in the orbit of the Earth which result in changes in climate over periods