PDS AP Environmental Science 8th Period 2010-11

Jim Thompson is currently the head of young biodiesel production company called Southeast Biodiesel, and Mr. Thompson is also a strong advocate for the potential biodiesel has as a fuel source in automobiles. To start his presentation, Mr. Thompson outlined the differences between a standard gasoline engine and a diesel engine. While gas engines mix the petrol with the air and use a spark to ignite the controlled explosion necessary to move the piston, diesel engines first compress the air, which will heat up, then add the fuel which ignites when it comes in contact with the heated air. Like all engines, diesel engines require lubrication to prevent damaging friction between the moving components. To alleviate this problem, sulfur is added to the fuel to help lubricate the engine, but sulfur is an emission linked to various air pollution problems, like photochemical smog. Eventually, the government started to regulate the maximum parts per million of sulfur in diesel engine emissions until it reached 15 ppm in 2007. With new legislation, alternatives to petroleum based diesel became increasingly popular and the biodiesel market was created to meet this demand.

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Biodiesel can be made out of a variety of sources, most of which are wastes products from our everyday lives. Currently, the most popular source of biodiesel is used cooking oil from restaurants. Rather than throw out this organic waste it can be reused to power our cars and trucks, which adds to the appeal of biodiesel as a “cleaner” alternative to petroleum based diesel. Biodiesel also replaces the lubrication lost when sulfur could no longer be used. Unlike most fuel sources today, biodiesel is not a threat to human health or an ecosystem’s health when spilled. Contrary to popular belief, biodiesel is not flammable, it is not carcinogenic, and it readily biodegrades in an ecosystem. Theoretically, if a truck hauling biodiesel crashed and lost its cargo, there would be not risk of an explosion and all clean up crews would need to is wash it off the road with water. According to Mr. Thompson, biodiesel preforms just as well as petroleum based diesel and it will leave your car cleaner and, as a result, running longer. On top of that, regular diesel engines do not require expensive modifications to run on biodiesel. Like every other energy source, biodiesel is not without its drawbacks.

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The biggest drawback to biodiesel that Mr. Thompson described was its high price. Biodiesel is typically more expensive than petroleum based diesel due to the fact that it is not widely available. Most of the biodiesel produced is used in conjunction with normal diesel fuel to reduce sulfur emissions and keep the engine lubricated. Another drawback to biodiesel is its tendency to gel in cold weather making it impractical during harsh winters in countries like Canada or Russia. Biodiesel might also clog the fuel filter. Once the industry starts to expands, the price will drop and might make biodiesel a feasible, cleaner alternative to petroleum based fuels.

-Solar energy has become a very popular way to provide energy or electricity for many different buildings and homes. There are two main ways to make use of solar energy:

1. Passive Solar Energy – Uses the light and heat from the sun without using and collectors or solar panels. This technology mainly deals with the building’s design and structure. (Ex : Having windows to allow sun to pass through and warm area up or having black, thick walls to capture the heat and help hold it)

2. Active Solar Energy – This technology uses things such as solar panels and grids to capture the sun’s energy. (Ex : Many houses have solar panels on their roofs to absorb the solar radiation for heat or heating water)

-Although many people want solar energy used for their homes, a lot of people do not want to go through the trouble to put the panels on their homes for their own reasons. That is when people decided that something else had to be done; they came to the conclusion of “midsized solar farms”. This is becoming so popular because it is a clean way to gain access to renewable energy.  The following is a picture of a midsized solar farm in San Francisco:

http://www.npr.org/2011/03/16/134341220/midsize-solar-installations-grow-at-light-speed

They are also doing this in places like Sacramento where people only have to pay 11 dollars a month for electricity provided from solar panels that are 30 miles away from downtown. Click here to read more on these midsized solar farms.

-This video talks about Spain’s solar energy problems and solutions that are currently taking place. Here there are hundreds of mirrors focusing on a tower of water to create great amounts of steam that produces electricity to thousands of homes. One of the problems is that when it is not sunny, there is no electricity. However, they have found a solution to this problem. They stock up on the energy for when it is dark or cloudy and the extra heat they collect is stored for the times when there is so sun out to create the steam needed for electricity. Both of these examples of solar technology usage prove that solar power has become increasingly accessible to people around the world today. Use of solar technology will continue to increase as technologies improve, prices fall, and government support increases.

Climate is a very different concept then what we would call weather. While weather is a very local phenomenon, Climate is studied on a larger regional scale. Weather also changes and is studied on a hourly to weekly basis. Climate, on the other hand, needs to be studied on a much more long term scale that is usually based on decades. Weather and climate also differ in the specific areas of the atmosphere they occur. Weather is usually found in the lower troposphere, while climate is found in the lower stratosphere. Climate and weather are very different things, but they are related because the general “big picture” concept (climate) determines what is “normal” weather for a specific area.

We are now left with the question, “What drives and determines climate?” Through a couple of simple experiments we were able to answer this question. In the end there are three major factors that develop climate.

1. Uneven Heating of the Earth:

The tilt of Earth’s axis, its spherical shape, and its orbit are the primary reasons why some areas are heated more then others. The tilt of Earth’s axis (23.5 degrees) and its orbit work together to produce seasons. The the tilt never changes instead it is oriented differently depending on where the Earth is in its orbit. During its orbit, one hemisphere might be closer or further away from the sun then the other hemisphere. This creates seasons when a region will experience more heat then another.

Finally, the spherical shape of the Earth makes light hit the atmosphere at different angles. As light reaches the poles it has to go through more atmosphere then it would at the equator because of the angle it hits the atmosphere. One comparison can be the concept of sloped armor on vehicles (see picture). The fact that light cannot reach areas with higher or lower latitude further adds to the uneven heating of the earth. Our experiment in class involved a tilted globe with aquarium thermometers stuck on different latitudes and a lamp to heat the globe up. After a few minutes the poles where cooler then the areas closer to the equator.

2. Different Characteristics of Land and Water:

The most significant difference between land and water are their specific heats, or the amount of energy needed to heat something up one degree. Water has a very high specific heat and will be cooler then land during the day because in needs more energy to heat up to the same temperature, but the oceans will be warmer at night because they will retain this heat better than landmasses. This is why people call water a “heat sink”. Land and water are also not distributed equally on the globe, so there are always warmer regions and cooler regions at any given time. Air at the warmer areas will rise then move over a cooler region and fall. This action creates convection cycles which form the basis of global wind patterns. In class, we had two tubes that were connected to each other, and one tube had a beaker of hot water in it and the other a beaker of cold water. Mr. Willard then stuck a burned stick down the top of the cold tube. After a few minutes, the smoke fell to the bottom, shifted to the hot tube, and started to rise out of the top of the hot tube.

3. Rotation of the Earth:

Lastly, we discussed the effect the rotation of the planet has on climate. We watched a quick video on the Coriolis Effect, which described why winds can blow to the east and west rather then just north and south, due to convection cycles. The Coriolis Effect shows how things appear to curve when the move across a spinning object because the object moves under the traveling projectile. The move used the example of a carousel and throwing a ball to prove this point. When the carousel was not moving, it was easy for the boys on the carousel to throw and catch a ball. When the carousel started moving, the ball looked like it was curving because when the ball was thrown its target was moving from its past position as the ball continued going straight. The same thing happens to wind currents that “curve” around the planet as it moves which creates winds that can travel east or west.

The most pressing environmental issue facing man today is the increasing scarcity of arable land as the population increases. Unless man can find more efficient and sustainable agricultural techniques, people will continue a wasteful process of transforming forests and other ecosystems into polluting agricultural factories. If we can develop more efficient methods of farming, we could keep arable soil as a renewable resource and sustain a growing population without losing the ability to feed ourselves in the future.