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.
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 MattP from the other class.
Before Mr. Thompson, the CEO of a Biodiesel fuel company, came to speak to us on Friday, what did our class know about Biodiesel fuel or even just diesel fuel? We knew that diesel fuel was more expensive at gas stations than gasoline, that trucks and other large vehicles often run on diesel fuel, and that diesel fuel would destroy a gasoline engine. But that was about it.
The first thing Mr. Thompson want to make clear to us was that BIODIESEL IS NOT ETHANOL. Ethanol is a corn-based fuel that is made by distilling the sugars and starches into alcohol. It is then mixed with gasoline. Ethanol is not only less efficient than gasoline but it also takes away from our food supply. Basic rule of economics: when the supply of a product decreases the price increases. On top of its lack of efficiency and the fact that it increases the price of food, because it is corn-based all the same fossil fuel inputs and environmental impacts associated with farming. When you add up all these costs ethanol is energy negative (it takes more energy to make it than it provides) and in the eyes of Mr. Thompson and many others to be a bad fuel.
Mr. Thompson went on to explain what biodiesel fuel actually is and does. Biodiesel is fuel made from natural oils (soy, canola, poultry, algae, or Mr. Thompson’s company made fuel from used cooking oil) that can be used in a diesel engine. It can be combined with petroleum-based diesel fuel in any percentage and still run a diesel engine. In fact, the main reason biodiesel even needs to be mixed with petrodiesel fuel is that it tends to congeal when it is cold and block up engines. Petrodiesel’s lower freezing point prevents this tendency when the two are mixed. Compared to regular diesel fuel biodiesel fuel can also reduce carbon emissions by as much as 75%.
Just a couple of videos to show you how biodiesel fits into our country today
Mr. Thompson finished his lesson by telling us what biodiesel is not. Again IT IS NOT ETHANOL. It is not simply waste vegetable oil taken from someones kitchen and dumped into a gas tank. It has to be processed first or else it would eventually ruin your engine. On the downside, in most places it is not cheaper than regular diesel fuel or gasoline or available in as great quantities… yet. But on the upside it is not flammable, hazardous, carcinogenic, and since it is just natural oils, it biodegrades very quickly.
Biodiesel fuel has many exiting possibilities and in a few decades it could be one of our major sources of fuel.
*Note: Since we did not have enough folks to take this topic, here is a guest post by RayS and MattP from the other class.
Pikachu, quick use thunderbolt!
Foe’s Blastoise fainted.
For the millions of you that have played Pokemon, it seems obvious that electricity is water’s kryptonite; they don’t mix! But in the world of modern science, nearly twenty percent of all electricity comes from hydroelectric plants (imagine that Ash!). Source: Friedland and Relyea Environmental Science for AP
To illustrate the vast potential of Hydroelectricity as an alternative energy source, check out this brief video of China’s Three Gorges Damn (Danjiangkou Dam), the largest in the world.
Hydroelectric power uses dammed reservoirs to direct the flow of water through a penstock and then past a turbine that generates electricity. Watch this short video to see what I’m talking about, and if you don’t have time for the video, check out the diagram.
Hydro electricity takes “hydro” and a substantial initial investment, and not all countries have the water and resources to make hydroelectric dams. The good new is that hydroelectricity emits no pollutants once constructed, and there are other ways to generate the hydroelectricity without a large river such as, run-o-the-river and tide. These use the same concepts, but don’t have reservoirs to direct the flow.
Get it? Got it? Good.
Things to consider:
fish ladders: for migratory fish during their mating season.
Siltation: the plague o’ hydroelectric dams! Silt from the water builds up behind the dam and has the potential to clog the penstock.
This type of biofuel is known as biodiesel. As the article mentions, the use of cooking oil as fuel for the plane does reduce the dependence on petroleum, thus acting as a substitute. However, this doesn’t mean that the process is any less expensive. In fact, using the biodiesel turned out to be much more expensive than using all petroleum as jet fuel. So, there are obviously advantages and disadvantages to this alternative energy source.
So, what are some other alternative sources of energy? Another common biofuel that we use is ethanol, an alcohol that is mixed with gasoline to produce a mixture called gasohol (the most common mixture in the United States is 10% ethanol, 90% gasoline). How is it produced? Take a look at this short video clip from the Ethanol Promotion and Information Council (the last 30 seconds of the video promote the use and production of ethanol in the United States–presenting a clear bias–however, the first 3 min and 20 secs describe the process with easy-to-follow animations):
So basically, there are two ways to produce ethanol: from corn and other starchy crops, and also from cellulosic materials. The issue that many bring up with ethanol production from corn is that it will drive food prices up. Take a look at this article from February 2011 in USA Today about the threat that ethanol production brings to the world’s poor as food prices rise due to less corn in production for food: http://www.usatoday.com/money/industries/food/2011-02-09-corn-low_N.htm
Finally, not all countries in the world (especially developing) have the capital or the infrastructure to produce and use biofuels, like ethanol and biodiesel. As a result, more of the developing world uses solid biomass as their source of biomass energy. One such source is charcoal. But how is it made? Take a look at this video taken from an episode on Discovery Channel’s “How it’s Made” series which describes the industrial charcoal production process (stop at 3 min–the rest of the video describes what happens to the charcoal pieces that are used for grilling purposes):
Since it is produced from heating wood, charcoal is a renewable energy source. Using these forms of biomass energy is an important piece of renewable energy. In fact, biomass energy accounts for more than half of renewable energy in the US (textbook).