PDS AP Environmental Science 8th Period 2010-11

On Tuesday we covered Sustaining Biodiversity, and I will be covering the species approach(Will W. has already covered the ecosystem approach). The three types of species extinction are as follows:-Local Extinction (or extirpation), -Ecological Extinction (when a species can’t fulfill a niche), and -Biological Extinction (global, permanently gone)

I know terms like endangered and threatened are tossed around a lot today, but they aren’t just based off someones “feelings” about there not being enough of a certain species; they’re legal terms put in place by the Endangered Species Act of 1973. This law placed species into two categories: -Endangered Species (a species in threat of extirpation in all or part of its range), or -Threatened Species (a species in threat of becoming endangered in all or part of its range).

Here are some characteristics of Extinction-prone species: -low reproductive rate, narrow distribution, fixed migratory patterns, specialized niche, feeds at high trophic levels, rare/commercially valuable, large territories(larger territories=more interaction with humans=more likely to be hunted/exterminated/have habitat destroyed)

Here is a link to a brief video from a documentary on  Species Extinction

*sorry about not embedding the clip, but I kept getting an HTTP error overtime I tried to post it.(http://www.youtube.com/watch?v=vpxmTZ02FXg uploaded to Youtube by: livehistoryvideo on Feb 7, 2008, originally part of a documentary)

Yeah, I realize that clip was a little dramatic near the end…but it did a great job of addressing Utilitarian, Moral, and Ecological reasons of the importance of species (see lower in post for clarification of terms).

Human Impacts: As the video pointed out, humans have accelerated extinction rates (1,000-10,000x the background rate0, and this leads many scientists to believe we are now in our 6th major extinction period.

Some of the reasons for acknowledging the Importance of Wild Species are: -Utilitarian: humans benefit/rely on many wild species such as bees for pollination. -Aesthetic: quite simply enjoying the natural beauty of wild species(cute pandas…)-Moral: some might argue that all living things have a right to live, and humans should therefore feel morally obligated to acknowledge and protect wild species. -Ecological: If one species goes extinct then other species in the exterminated species habitats will be affectedly negatively.

Causes of Premature Extinction: borrowing Mr. Willard’s acronym here, HIPPO; which is a rank-ordered list that stands for Habitat destruction & fragmentation, Invasive species, Population growth (humans), Pollution, Overharvesting (including poaching).

International Treaties and Conventions:

Convention on International Trade in Endangered species (CITES)

Convention on Biological Diversity (CBD)

US Federal Laws:

Lacey Act

Endangered Species Act (ESA)

Marine Mammal Protection Act

Wilderness Act

http://www.wilderness.net/index.cfm?fuse=NWPS&sec=legisAct

Preservation vs Conservation:

Preservationists like John Muir are focused on keeping wilderness as untouched as possible in order to maintain the biodiversity of a certain region. Conservationists like Gifford Pinchot are much more interested in finding ways to use land and resources while at the same time limiting their use so these resources aren’t over-harvested (sustainable use).

How do we preserve and conserve:

Approximately 1/3 of the land in the United States is owned by the public. That’s more land than any other country in the world has devoted to public use.

http://www.preservationnation.org/assets/photos-images/issues/public-lands/public-lands-map.jpg

Types of Public Lands

1-Multiple-use lands – This includes National Forests and National Resource Lands

2-Moderately Restricted-use lands – This includes National Wildlife Refugees

3-Restricted-use lands – This includes National Parks and National Wilderness Preserves.

The tropics are a hotpoint of contention for land management. Areas like rainforests with high biodiversity contain plants that can be used for medicinal purposes, as well as house countless species of animals. That’s why the tropics have become known as a “biodiversity hotspot”.

The UN supports a plan called “Biosphere Reserve.” This involves protecting one core area in a place of high biodiversity that is surrounded by two buffer zones. The core area has had very little human impact, while the first buffer zone is a limited use zone for humans, and the second buffer zone is impacted a little more.

The first step in land preservation and conservation is to designate the land to a specific type of public land so that it may be protected by the federal laws that are already in place.

Since it was such a busy week with prom and since most of you met your scribe post obligations during the energy project, I did not assign scribes over the last few days. So, here is a collection of links from last year’s class on Global Climate Change for those that missed class:

Intro to Global Climate Change

Global Climate Change

Evidence and Consequences (of the Earth’s Warming)

Solutions to the Earth’s Warming Problem

*Since did not have a scribe for ozone day, I pulled this post by alum Kelly Cox ’10 out of the archives.

Today during the second half of class, we discussed ozone, or O3.

The first thing to recognize when discussing ozone is that there is good ozone, and there is bad ozone. You MUST be able to distinguish between the two of these!

Good ozone (O3) is responsible for absorbing and blocking about 95% of harmful UV radiation from the sun in the stratosphere (NOT the troposphere). Good ozone is what we want to maintain in the stratosphere, obviously. Without it, humans and plants are exposed to UV-A and UV-B, which penetrate through the skin and cause DNA to lose electrons. This leads to tumors called carcinoma and melanoma. Without good ozone, we are also at risk of cataracts, severe sunburn, skin cancer, lower crop yields, and less phytoplankton which the food chain depends on.

Bad ozone is a main component of photochemical smog, and obviously we want to minimize the amount of bad ozone that is released into the atmosphere. Bad ozone irritates the eyes, nose, and lungs, and damages plant’s leaves.

One of the most common misconceptions about ozone is that there is a “hole” in the ozone layer. In reality, the issue at should be referred to as “ozone thinning.” The ozone layer varies in thickness and concentration throughout the stratosphere. Thick is obviously better because it can better protect us from UV radiation. Here is a diagram showing the varying concentrations of ozone in the stratosphere but NOTE: No where is there a “hole” or complete absence of ozone!!!

NOTE: There are different concentrations of ozone, but there is NO "hole" in the ozone layer, only thinning. Source: http://www.skincancer.org/ozone-and-uv-where-are-we-now.html

The “hole” is the largest or the most thinning occurs during the spring months (September-October) in Antarctic.

CFCs (chlorofluorocarbons) were discovered in 1928, and at first they were considered “the dream chemical” because they were useful and versatile, yet they weren’t explosive or dangerous, or so they thought. They were used for coolants in refrigerators, propellants in aerosol cans, and in plastic bubble packaging. But in 1974 research proved a reaction of CFCs in the stratosphere, which was destroying good ozone. When UV light hits CFCs, the chlorine in the atmosphere is free and reacts with O3 causing these series of reactions:

Cl + O3 –> ClO (unstable) + O2 ClO + O –> O2 + Cl….. then this Chlorine continues to react with O3 creating a vicious cycle where good ozone is being removed from the stratosphere. Once this discovery was made, a large movement to remove all CFCs from the market quickly began. Here is a good description of this reaction that takes place in the stratosphere that Mr. Willard sent me (I’m not sure who to credit this??):

A good description of how O3 is destroyed by CFCs in the stratosphere

The Montreal Protocol has been very successful in eliminating CFCs in most products. Almost every country has signed on to it now, and ozone remediation is working, but slowly.

Since the Montreal Protocol was started, major steps have been taken to reduce the amount of CFCs in products worldwide. Source: http://www.amstat.org/publications/jse/v17n2/nelson.html

First, we talked about smog. Term coined by combining smoke + fog to get smog. Here are the two types we learned:

1. Sulfur-based Smog: “industrial smog”
2. Nitrogen-based Smog: “photochemical smog”

Sulfur-based Smog takes on a gray color. When coal is burned compounds within the coal interact with atmospheric oxygen which then causes iron oxide and sulfur dioxide to be released in the atmosphere. *Sulfur oxides are primary air pollutants. The sulfur dioxide in the air can oxidize, then dissolve into atmospheric water droplets to form sulfuric acid. Sulfuric acid is a secondary air pollutant and a main component of acid rain. Acid rain contributes to deforestation and the corrosion of buildings, statues and paint.

"industrial smog"

Nitrogen-based Smog takes on a brown color. The combustion of an engine leads to the release of many different chemicals. One compound in particular is NO2. When ultra-violet rays from the sun hit NO2, that is now in the atmosphere because of vehicle emissions, an Oxygen atom breaks away but quickly combines with O2 to form O3 also known as ozone. Ozone is good and bad, it just depends on where it is in the atmosphere. Ozone belongs in the stratosphere where it can protect us from the sun’s harsh rays. When ozone is down in the lithosphere it is considered a pollutant because it traps heat and contributes to thermal inversion.

"photochemical smog"

Mr. W's Car Emissions Diagram

This diagram basically explains that the combustion of an engine leads to emissions of both regulated and unregulated pollutants. (Click to enlarge image) CO, hydrocarbons, NO, NO2 and particulate matter are all regulated. CO2, H2O and N2 are unregulated. The result of these emissions produce primary and secondary pollutants. Secondary pollutants include: ozone formation, acid rain and photochemical smog.

We had a few folks out visiting schools Friday, so here is the scoop.  After reviewing the energy unit tests, I briefly reviewed the structure and composition of the atmosphere.  Then, I did a brief into to tropospheric air pollution.  The Clean Air Act (originally enacted in 1970) has been one of our most successful environmental laws.  This law empowered the EPA to establish  the National Ambient Air Quality Standards (NAAQS), for certain air pollutants.  There are 6 main pollutants for which the EPA has set standards: NO2, O3, SO2, CO, Lead, and PM (particulate matter or SPM, suspended particulate matter).  These are MINIMUM standards for acceptable air quality! Here’s the memory trick I offered the class:

Question: How do you remember the list of air pollutants monitored by the NAAQS developed by the EPA?
Answer:  “NOSCLP”
NO2
O3
SO2
CO
Lead
PM  (particulate matter or spm)

Get it?  you would need a noseclip to protect yourself from the NOSCLP air pollutants…haha.

*Here is a wonderful, wonderful, wonderful interactive web site that gives you details on the health effects of each (you should have this on pg. 4 of Chp 17 Study Guide also but check it out): http://hank.baaqmd.gov/cleanairprimer/IIIA3.html

Image Source

You all are probably more familiar with the Air Quality Index (AQI).  The AQI is set by the EPA and is based on primarily on measurements of particulates and ground-level ozone.   An AQI value over 100 is considered unhealthy (orange).  You are most familiar with this when the weather man gives you a color value for today’s air quality (click here for that scale).  Ozone is the biggest concern, since that is a clue photochemical smog is forming. Cities that spend too many days in the upper index ranges can be penalized by the federal government withholding highway improvement funds.  Charlotte has had some issues with during our summers lately!  You can see North Carolina AQI “forecasts” here.

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.

http://assets.bankspower.com/tech_article_images/63/Fig-1.jpg

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.

http://www.heatingoil.com/wp-content/uploads/2009/10/used-cooking-oil-bu.jpg

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.

Hydrogen Energy

Hydrogen energy uses hydrogen ions and a process called electrolysis to create electrical energy. Heres a diagram and  two short videos describing this process:

How Electrolysis Works

What this video doesn’t show you is that the energy needed to break apart these molecules must come from another source (e.g. coal, natural gas, or renewables like solar and wind.) To be a truly “clean” process this energy must come first from other “clean” sources (like wind and solar).

How Electrical Energy is Produced

http://biodiesel.environmentalactiongroup.org/hydrogen.html

Hydrogen energy is a very efficient source of electrical energy:

• It uses up to 75% of the energy produced by the process (it can use up to 90% if the heat energy it creates is also harnessed.)
• its byproducts, if using water as a fuel source, are only heat and H2O.

However, as perfect as it may seem, Hydrogen is a very volatile and dangerous substance (as illustrated by the Hindenburg disaster.) and is dangerous to transport long distances. Not only this, but scientists fear that releasing more hydrogen gas into the atmosphere will deplete the ozone layer by binding with ozone molecules.

As of right now, there are very few people using hydrogen power in todays world. One of them is Iceland. In 1998, Iceland signed an agreement to proclaim it’s wish to change into a “hydrogen powered society”.  It attempted to do this by introducing hydrogen fueled buses in Reykjavik. These buses used only hydrogen fuel and electrolysis to create all the energy needed to run. From an ecological standpoint, these buses were a success. However, Icelands recent economic troubles have put these buses out of commission, but have not put a stop to their research. Recently they have created a few private car prototypes that run completely on this process, and can go over 350 miles without refueling. In the future, with the help of solar and wind energies, this process could help rid us of the need for fossil fuels.

1) Energy and Power Calculations

E=P x T   (that’s   Energy in Joules= Power in Watts multiplied by Time in time units   )

Like wise   P=E/T

example: How much energy (J) does a 30 W bulb use if on for 10 minutes?            E=PT  —>  E=30W x 10 minutes x 60 seconds

E=18000J

2) Heat Transfer Calculations

Q=m x c x delta T

(that’s    Amount of heat energy in calories or BTU= mass in grams or lbs x specific heat of water (generally 1) x change in temperature in degrees C or degrees F)

3) Cost Basis

Units Used x Price/Unit= Price

4) Efficiency

Input of Energy= output/efficiency as a decimal

Let’s say a 60W bulb is 5% efficient —>       60W=X/.05  —>    60(.05)=X  —> X=3W to light

Here is a list of common efficiencies: Incandescent=5%, CFLs=20-25%, Coal Power Plant=30-35%, Nuclear Plant=25%, Car Engine=20-25%, Photosynthesis=1%

http://www.richmondhill.ca/subpage.asp?pageid=epw_energy_efficiency_open_house

http://www.savagechickens.com/images/chickencar.jpg

If you thought the photo by Richard Box of the “leaky” high voltage transmission lines was neat, you can check out more of his photography here. I thought that was an interesting intro to a subject your book seems to ignore-how the electricity gets from all those different types of power plants to your home:

Power Transmission Infrastructure

Image source (and article on how there are plans to replace our “dumb” grid with a “smart” one): http://newsone.com/nation/associated-press/obama-administration-will-spend-3-4-billion-toward-smart-power-grid/

You need a basic working knowledge of “the grid” if you are going to make sense of some of the free response math questions on the AP exam. If you missed class, the best makeup lesson I can offer is to go through the web pages of How Power Grids Work at HowStuffWorks.com.

*Someone else has scribe duties for the energy math problems covered in class today, so look for another post soon.