PDS AP Environmental Science 8th Period 2011-12

   Apple Data Center puts Charlotte in national spotlight as the debates over hydrogen fuel continues! Trying to become the nation’s “greenest” and “most technologically advanced” company, Apple recently has declared that they are fueling their new data center in suburban Charlotte solely from hydrogen power. While no one is faulting Apple for trying to use this very clean source of energy, a conflict of interest debate has come up and Apple is facing heat from the press.

As gas prices have continually climbed over the last decade or so, hydrogen power has long been regarded as the “energy of the future.” Pictured below, the chemical equation of hydrogen power shows why many people have begun to support research and development of this clean energy.

2 H2 + O2—-> energy + 2 H20

    Because energy and water or the only byproducts of this chemical reaction, it’s not hard to see why many Americans say they would prefer the use of hydrogen fuel cells rather than dirty, greenhouse gas emitting gasoline or coal. But, at this period in time there are a number of reasons prohibiting us from seeing widespread use of hydrogen fuel cells.

1. It currently takes more energy to yield pure hydrogen then the cells omit when they are used.

2. Fossil fuels are the main source of energy used when trying to yield pure hydrogen.

3. The process used to “take the energy” is very complicated (as shown in the video below) and it would be very expensive to convert all formerly gasoline run systems to this process.

http://www.youtube.com/watch?v=6UwSazq8GTU

4. Lastly, the use of hydrogen fuel cells, especially in automobiles is impractical. Hydrogen either has to be..
a) Kept at very high pressures, which would cause fuel cells to be much larger than their gasoline tank counterparts to hold the same amount of potential energy. Or
b) Kept at very low temperatures to keep the hydrogen in its liquid form, which is infeasible considering our cars often spend long periods of time in warm weather.

Sources:

http://www.foxnews.com/scitech/2012/04/09/apples-hydrogen-power-plans-fueled-by-al-gores-conflict-interest/

http://images.apple.com/environment/progress/images/maiden_facility.jpg

http://www.youtube.com/watch?v=6UwSazq8GTU

http://www.chicagotribune.com/business/ct-biz-0404-apple-fuel-cells-20120404,0,7442283.story

Tags: energy, hydrogen, renewables

I have two questions.  The first one is if we have to know anything about the details of how exactly a closed landfill is engineered.  If so, my second question is if anyone can describe the setup for me? I know that some mixture of clay, sand, and liner are involved but I’m not exactly sure in what order and why.

 During class, on November 28th, we discussed the equations necessary in order to do population math on the AP exam.  There are three main equations and a couple of small tips that we discussed in class that will be helpful when studying for the AP exam.  There were two main points that we mentioned in regards to the AP exam.  One, no calculators are allowed during the exam.  Everything has to be done by hand and you have to show your work.  And two, most numbers that will be given on the AP exam will either be whole numbers or easily rounded.  So although it’s kind of annoying that we’re not allowed use calculators on the exam, it’s not like we’re being asked to do trigonometry or anything that truly requires a calculator.

Tags: demographics, math, population

In class Monday, we discussed the importance and fundamental ideas of Ecology.  Ecology, known as the interaction between biotic and abiotic components in an ecosystem, is one of the most important units in this course (pretty thrilled you missed the notes, right?).  These interactions include how abiotic factors in an ecosystem like pH, temperature, salinity, and sunlight will affect certain communities and populations.  However, the key in Ecology, and in this course, is to always look at the big picture and how individuals affect it.  This is different from our previous science courses when we would analyze specific individual components like atoms and molecules in Chemistry, and cells, organs, and health systems in Biology.  A perfect example of this is a pond.  In Biology, we would examine only individual species or certain processes like photosynthesis and cell respiration in algae.  Whereas in Environmental Science, we are going to study the pond ecosystem as a whole and issues a pond may face like algal blooms or pollution.  Another important lesson we learned Monday was about the trophic levels in an ecosystem.  A trophic system, more commonly known as a food chain, is a system that classifies and maps out a succession of organisms, what they eat, and what they are eaten by.
These trophic levels are (Starting at the top of the pyramid):

4.)  Tertiary Consumers: Organisms in the quaternary level consume secondary consumers.  E.g. Bald Eagle

3.)  Secondary Consumers:  Organisms classified at the tertiary level or above are carnivores or omnivores.  Meaning that they, at least, consume other heterotrophs. E.g. lions, snakes

2.)  Primary Consumers: All organisms classified in trophic levels above level one are known as heterotrophs.  These organisms are incapable of photosynthesis and must obtain their energy through consuming other organisms.  In the case of primary consumers, they eat only plants and are herbivores.  E.g. most insects, tadpoles

1.)  Producers:  Also known as autotrophs, these organisms undergo photosynthesis and make their own energy.  This means that they do not consume other organisms and are the bottom and base of the trophic system. E.g. plants or algae

Although these trophic levels help summarize a very intricate and complex natural process, there things that it fails to mention.  The first point is that you are unable to see if an organism is an omnivore, both plant and meat eating, organism.  Second, Food chains are unable to show the impact of decomposers or detritivores in an ecosystem. Decomposers, such as fungi or bacteria, break down the remains of organisms at any level.  Meaning that they wouldn’t really fit in the pyramid and are given the title Trophic Level 0.  Lastly, the food chain is unable to show the role of detritivores in an ecosystem.  Detritivores feed on detritus, also known as nautre’s trash.  Since they are not producing their own energy, but not eating any of the consumers, they don’t fit in the food chain either.  So what can we do to properly show that decomposers and detritivores play a vital role in ecosystems?  Food Webs.  Shown in one of the pictures below, food webs accurately portray who eats who in an ecosystem.  Although it may be harder to tell what trophic level they are on, it makes it much easier to see who are omnivores, decomposers, and scavengers.

Tags: ecology, ecosystems

In my opinion, the biggest environmental problem we face today is the constant diminishing of the world’s biodiversity.  This issue looks habitat destruction, deforesting, and polluting.  All of the following, done by humans, have caused different unique species to go extinct.