PDS AP Environmental Science 5th Period 2010-11

If you have just stumbled upon this blog, note that our class no longer meets and will no longer be adding new content.  Feel free to click around and see all that we’ve learned about environmental science this year. -Mr. W

After watching Who Killed the Electric Car (2006), we took a look at some of the new plug-in electric cars from Chevy, Ford, Nissan, and Tesla now on the market. Are electric cars really the answer for ending our dependence on foreign crude oil? Could it be that simple? This Daily Show clip (8 minutes) is one of my favorites on the history of American presidents trying to get us to cure our addiction to oil:

So, your text had a section on carbon offsets, but we never discussed it in class. There are many companies out there now marketing carbon offsets to reduce your “carbon footprint.” Terrapass is a popular one. You can offset one year’s worth of air travel (an estimated 8,000 pounds of carbon emitted) for just $50.60 as of 5/5/2011. Your money goes to support wind farms and methane capture projects-that’s how the carbon is “offset.” Some companies will even plant trees to offset carbon produced by your lifestyle.

So, does this approach mitigate (lesson) global climate change or encourage “cheating?” Watch this clever parody of carbon offsetting by a couple of Brits:

*If you want to learn more, visit www.cheatneutral.com

So, what do you think?

*Try www.carbonfootprint.com to for a carbon calculator if you want to assess how much carbon dioxide results from your lifestyle.

As we approach the final day before the AP exam, have you reviewed the nutrient cycles? Knowledge of these cycles is critical-they tie everything together.  In the fall we learned primary reservoirs, key chemical reactions, and anthropogenic impacts.  I also had each of you write a creative short-story of a cycle.  Here is a good one by JoeY:

Being a nitrogen in a nitrate ion was getting boring, especially as I drifted through the sea. I needed to get as far away from here as possible. One day, as I am minding my own business, a denitrifying bacteria comes up to me and asks, “ Want a little adventure in your life?” I couldn’t say no to a ticket out of here. Suddenly, I am pulled away from my oxygen parts, and I start floating up into the clouds. What a view! The atmosphere was so high up that I could see everything! And I also met many of my fellow nitrogen molecules. I started drifting back down to see land beneath me. Then, as soon as I was close enough to a legume, a nitrogen-fixing bacteria takes me in and fixes me up with some hydrogen ions. But as soon as this happened, a plant sucks me into its roots. I stayed in the plant for a while, but when the plant died, I was decomposed and returned to the soil. When I was in the soil, I went through a similar process and became ammonium. But I met some new bacteria friends that converted me into a nitrite ion. Then, another bacteria transformed me back into just nitrogen, and I floated back into the atmosphere. But my time in the air didn’t last long. I was fixed into ammonium again, but this time, I was in the ocean. Some nitrifying bacteria turned me into a nitrite ion. Then I was immediately turned into a nitrate ion. What an adventure!
So, do you remember the steps of the nitrogen cycle? Do you remember the formulas for these forms of nitrogen? Do you recall all the ways humans alter this cycle?

I know things are winding down, but I was amazed by all the recent news stories that deal with our units of study. At this point in the course, reading the news is a way to study. This AP exam is constantly being rewritten as new research is published or new environmental disasters occur! Check out any that interest you:

NPR: Fukushima Vs. Chernobyl: Still Not Equal

BBC: BP oil spill: The environmental impact one year on (yes, it’s been a year already!)

NPR: Researchers Link Extreme Rains To Global Warming

NPR: Washing Away The Arctic Coastline (more on sea level rise)

NPR: Climate Change Trends: Carbon Emissions Giants (data/maps)

NPR: Tapping The Earth For Energy Savings Year-Round

NPR: Our ‘Toxic’ Love-Hate Relationship With Plastics

NPR: Repelling Bugs With The Essence Of Grapefruit

NPR: The Worldwide ‘Thirst’ For Clean Drinking Water

HAPPY EARTH DAY!

If you did notice lately, it is very “hip” to “green.” I’m watching my favorite Thursday night NBC comedy shows, and seeing all these public service announcements for “green week.” Heck, even the NBC peacock logo is green this week! Check out NBC’s slick website: http://www.nbc.com/Green/

And, FOX is getting in on the act too. Check out their slick website: http://www.fox.com/greenitmeanit/

This type of public relations stuff is called “greenwashing.” Here’s a definition (can’t find or recall the source):

Greenwashing is the unjustified appropriation of environmental virtue by a company, an industry, a government, a politician or even a non-government organization to create a pro-environmental image, sell a product or a policy, or to try and rehabilitate their standing with the public and decision makers after being embroiled in controversy.

So, why is what NBC or Fox doing this week considered sorta sly? Well…do you think the network executives are doing it for the network or us (or both)? You decide.

If you want to know more, here are a few “watchdog” sites that monitor greenwashing:

Sourcewatch:

http://www.sourcewatch.org/index.php?title=Greenwashing

Greenwashing.net

http://www.greenwashing.net/

Corpwatch:

http://www.corpwatch.org/article.php?list=type&type=102

So, be a smart consumer, not all that is green is good. ANY group can claim to be green-there is no government standard! Love to discuss any of this with any of you here or in class one day…can you think of other examples you’ve seen?

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

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.

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.