Sorry to say the year is over. I really enjoyed our time together. Best of luck to each of you in college and beyond.
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
Well, you all made it. Now that the course and AP exam are behind you, I hope you pay attention to the environmental issues that lie before you. Here are just a few of the issues we have studied that have popped up in the news the last few weeks. Feel free to share things you come across with me here or by email.
We have 3 seniors who in this class that are participating in the Global Studies Program here at PDS. They’ve shared their global leadership project blogs with me, and since they involve environmental issues I am sharing them with you:
So, while your text does introduce the concept of carbon neutral it did not mention carbon offsets, which have become a hot ticket in “climate change mitigation.” 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 really mitigate global climate change or just encourage more “bad behavior” (burning of fossil fuels)? Watch this clever parody of carbon offsetting by a couple of Brits:
Since it is so close to the AP exam and all of you have fulfilled your scribe post obligations, I won’t start the list over. So, here is a collection of links from past classes on major air pollution issues and global climate change for those that missed class. While written a year or two ago, all the info is still correct and relevant:
After testing a handful of vehicles in each class, we tried to analyze the class data for trends. It has become harder and harder to do as vehicle emissions have become so much “cleaner” over the last decade (yes, I said it). If we had the time, this is the data I would love to gather:
Relationship between CO2, CO, HC (Click to enlarge)
One reason vehicles emissions have improved so greatly in the USA, is catalytic converter technology. Catalytic converters speed reactions to reduce the amount of NOx, CO, and HC coming out of an automobile. Check out how catalytic converters work at howstuffworks.com.
Catalytic converters are pollution solutions!
Why does all this matter? Well, NOx have a key role in the formation of ground-level (tropospheric) ozone and photochemical smog. Reduce NOx (and CO and HC), and you reduce ground-level ozone and photochemical smog. You need to be familiar with both types of smog (below) on the AP exam.
HAPPY EARTH DAY! Have you been good to your “mother?” You can see what others are doing around the country at the EPA website: http://www.epa.gov/earthday/
If you did notice lately, it is very “hip” to “green.” I’ve been watching my favorite NBC comedy shows lately, and seeing all these public service announcements for “green week.” Heck, even the NBC peacock logo is green! Check out NBC’s slick website (and the peacock): http://www.nbc.com/Green/
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:
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?
*Note: This is a guest post by JYang (’11) to illustrate what a good pre-lesson blog post looks like for our student-teaching project.
When you hear the words “Nuclear Superpower” the first thing you’d probably think about would be an image from the Cold War with stockpiles of nuclear warheads to kill off the planet earth several times over. But that was then – come to the 21′s century, bud. Sure we still have big bombs in commission, but ironically we have also adapted the most destructive weapon for non destructive purposes – commercial energy.
So y’all are probably thinking “whoa, is that possible? Is its power level over 9000???” Sure it is! but you need to know how electricity is typically generated in order to understand how nuclear energy works. Heres a simplified rundown of how we get most of our electrical energy (in reverse).
Electrical energy always comes from spinning magnets, or spinning some sort of shaft. thus: “Super merry-go-round” + magic = Electricity =
We power this super super merry-go-round not with electricity (because that would be stupid) but my moving some sort of gas or fluid through a turbine. its like holding a propeller and blowing into it — more magical moving particles + turbine + more magic = super merry-go-round
In most power plants this fluid is pressurized steam that is forced though tight chambers to get them moving fairly quickly. we get steam though the magic of heating water. — magical water + something that has hot air (like Mr. W, JK!) + even more magic = moving steam (moving particles)
So thats how we generate most electricity in a nutshell. its 1 part basic physics and 3 parts awesome magic. The only thing that differs between most typical power plant designs is how we heat the water. Obviously with a nuclear plant we use a nuclear reaction (not nukes). Here, instead of burning coal, we have a reactor core that is filled with radioactive material. This material can easily fission (the whole atom can be broken, yeah they told you atoms couldnt do that, well they can.) into smaller parts, however in such a reaction, although the number of particles is conserved, mass is not. the mass is converted into energy (heat). Here’s how that works:
Fissionable Uranium 235 is fairly stable by itself, but with the addition of a free nutron it becomes Uranium 236 which is highly unstable. — Uranium 235 + magical nutrons = really angry Uranium 236
The pissed off Uranium 236 decides it doesnt like itself so it splits into two smaller atoms in a bloody civil war creating smaller Krypton and Barium atoms as well as 3 nutron Al-Quida radicals. (this is a really hot situation so there is a lot of heat released)
The 3 free radicals run around and upset other happy Uranium 235 and repeats this process. Its like a positive feedback loop, except it gets VERY hot. Enough to make many pots of coffee.
Here’s a video that shows how this works.
But enough wharbl garbl, if its so good, why dont we use it?
Unfortunately, the Al-Quida radicals overcome Uranium 235 and cause too many of them to fission too fast creating too much heat. This situation in a nuclear power plant is called a Meltdown or where the core gets too hot and the whole thing basically “melts down” into a a soupy mixture that spews out radiation unsafely; just like the one in Chernobyl in the 20th century when they couldnt shut down their reactor in time. But even today, we are still having problems avoiding potentially catastrophic events from nuclear power. A recent tsunami that hit Japan has crippled safety features in a power plant that has become unstable. Here, like Chernobyl, they cannot seem to stop their reactor completely, but they are making every effort to keep it cool with seawater. HERE’S a link to what is really going on out in Japan. *NOTE-This was just over a year ago (3/11/11)!
Aside from these “minor” problems in today’s current events, Nuclear power has a lot to offer us in terms of energy. FIND OUT MORE TOMORROW IN CLASS!
Yes, there are some “other” sources of fossil fuels besides coal/oil/natural gas, namely oil (tar) sands and oil shale. Your book briefly mentions oil sands, but not oil shale (which you can read about here). Our neighbor to the north happens to rich in oil sands, which contains oil in a semi-solid state known as bitumen. This substance must be heated before the liquid crude oil can be extracted and refined. This 2 minute CBS 60 Minutes video clip shows an oil sands mine and what the bitumen looks like:
As you can see in the video, this involves a lot of strip mining–a very destructive process that means much deforestation (in Canadian taiga), habitat loss, and biodiversity loss. Look at this image from a recent National Geographic article on oil sands mining:
Strip Mining the Canadian Oil Sands
Such destruction is one of the main reasons environmentalists oppose this method of harvesting oil. The Canadian Association of Petroleum Producers insist that such mines undergo extensive reclamation (by law), and so the environmental damage is not permanent. Here is a short YouTube video by CAPP showing the mining process through reclamation:
An economic drawback to using oil sands is the amount of energy (heat) and water that must be use in the refining process to harvest the liquid oil (low EROEI value). Check out the steps of the refining process at HowStuffWorks.com. If crude oil prices are low, this expensive mining and refining operation may not make make a profit. But, if like the CBS video report states, Canada has enough of the stuff to rival Saudi Arabia’s crude oil reserves then we may have a way to break from of our dependence on OPEC supplies. America already imports most of its crude oil–maybe all that cash will now go to a trusted democracy? What about that proposed pipeline? Couldn’t that result in habitat destruction in the American mid-west? What if it leaks?
Today we compared the “conventional” fossil fuels-coal, petroleum (crude oil), and natural gas. You need to be familiar with what they are, how they are extracted, how they are refined, what they are used for, and the environmental impacts. There was a handout that you can find in our Unit 11 Google Docs Collection. This science teacher from England has put together a fabulous resource that summarizes much of this info: http://www.darvill.clara.net/altenerg/fossil.htm#adv
You have to know how to explain the operation of a coal-fired power plant in class, but this short interactive tour (with real pics and computer animations) will give you a better feel than the diagrams in your text. We can only take so many field trips, but this is one I would love to do if we had the time.
Many assume these cooling towers mean this is a nuclear plant, but they can be found a coal-fired plants also.