PDS APES 5th Period 2009-10

So…did you laugh at my memory-trick email about the six compounds the EPA must track under the Clean Air Act?  If you missed, it here is is again:

Q:  How do you remember the 6 air pollutants covered under NAAQS (National Ambient Air Quality Standards)?

A:  NOSCLP

NOx
Ozone
SO2
CO
Lead
PM

So, get it? You need a NOSeCLiP to protect yourself from the NOSCLP pollutants!  Now, click on this link to study using an neat interactive “The Nitty Gritty on the 6 Most Harmful Pollutants.”

You guys are most familiar with this monitoring system when you see the ozone alert days here in Charlotte.  This is part of the AQI (Air Quality Index) system used to notify the public when ozone and particulates reach levels that can cause harm-especially for those who already have compromised lungs.

Have you noticed this in the paper or on the news?

Image Source: http://www.airnow.gov/index.cfm?action=aqibasics.aqi

In class on Tuesday we spent most of the period discussing the evidence (the things we see happening) that shows the earth is warming.

The first piece of evidence we have are record global temperatures.  NASA concluded 2009 to be the second warmest hear on record.  With average global temperatures continuing to increase each year, scientists are starting to relate the temperature increase to global warming and pollutants that create it.

This picture shows the difference between a glacier before and after temperature rises--the glacier has melted significantly.

(http://www.dont-look-now.com/uploaded_images/huaraz.jpg)

Glaciers are taking a major hit because of the earth’s global warming.  According the the National Snow and Ice Data Center, there has been a global 0.74 degree celcius average temperature increase.  This has decreased both the size and number of glaciers found.  In Asia and South America especially, glacier water is a major life support for many people.  The glacier water keeps streams cool, preserve wildlife, and provide water for cities.  As glaciers continue to melt at an increasing rate, the sea level will eventually rise threatening coastal cities and shorelines in the future.

Polar ice is another indicator that the earth is warming.

-The Arctic (North Pole-which contains NO penguins) has perennial ice, which reoccurs each year, up to 10 feet thick.  Though since 1970, there has been a 10% loss of this ice per decade.  The Arctic also contains permafrost that if melted, can seriously damage the tundra and taiga, where it is most prevalent, in a few ways: forest damage, sinking roads and buildings, eroding riverbanks, and increased carbon dioxide and methane emissions.  There are estimates of billions of tons of methane stored in permafrost around the world-almost double the amount in the atmosphere today.  By releasing this methane, there would be a 10-25% increase in global warming.

Drunken Forests are an example of the effects of permafrost melting...the trees become weak in the soil and bend because they are unable to hold themselves up

(http://4.bp.blogspot.com/_8WdTOWE5Hp0/SGwEt1G2zWI/AAAAAAAABV0/R8_ocC8nkS8/s400/IMG_9485_1.JPG)

-Antarctica ( South Pole), covers about 10% of all of earth’s landmass and is covered by many glaciers up to 8000 feet thick.

-Greenland ice is spread out between three islands.  Greenland loses 20% more ice than it gains each year.

Next in class, we discussed the albedo effect and the positive feedback loop. The albedo effect is a measure of how strongly an object reflects light.  Lighter materials such as ice, sand, and snow all have a higher albedo.  The positive feedback loop, ironically, has a negative effect–it goes like this: rise in average temperatures, ice melts (glaciers, polar caps, arctic), loss of reflective ability as ice melts, water temperatures rise, more ice melts, etc.  Between 2004 and 2005, ice masses shrunk by 14% because of the positive feedback loop.

Positive Feedback Loop for Oceans

(http://www.yesmagazine.org/images/issues/88/45Pandora_LoopIceTEXT.jpg)

Other pieces of evidence we have that shows the earth is become warming includes weather severity and biome changes.

-Droughts have become very prevalent in the past few years because of rising temperatures.  Wild fires have become more sever in recent years as well.

-Coral bleaching in the ocean due to changing acidity of ocean water could impact a large percentage of underwater biodiversity.

-Temperature increases can effect animals and reduce biodiversity if animals are unaccustomed to the new higher temperatures.

*Again another positive feedback loop can be made for this: Warmer oceans->less carbon dioxide uptake, carbon dioxide increases, atmosphere becomes warmer, etc.

Coral Bleaching

(http://www.abc.net.au/reslib/200704/r135574_457949.jpg)

We finished class by mentioning a few consequences of earth’s global warming:

-A colder Europe

-Lower salinity in Arctic waters

-Smog increase-air quality worsens

-Spread of tropical diseases

-Changes in Biodiversity

(You can find more/see them all on the handout Mr. W gave out)

Any questions or comments, just post!

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

Today we discussed potential solutions to the problem of the enhanced greennhouse effect, also known as global warming. The only way to truly solve this problem is to attack the problem at its source: Greenhouse Gases. We need to decrease the amount of greenhouse gases, especially Carbon Dioxide, in the atmosphere by either reducing the production and emission of them (less adding) or by removing them from the air (more subtracting)

There are a few ways that we as a society can reduce greenhouse gas emissions. The first is to be smart and stingy with our fossil fuel use. Fossil fuels produce Carbon Dioxide when burned, which is the most abundant greenhouse gas. We should also use alternative fuel sources which give off no greenhouse gas emissions. Examples include wind, solar and nuclear power. We should alter our agriculture practices because almost a third of our current methane (a green house gas) production comes from cattle.  Government implemented Cap and Trade programs are also effective because they limit the amount of emissions factories are allowed to produce and allow the buying and selling of the permits required to emit greenhouse gases. This promotes our economy and the environment at the same time, which is a rarity. Great success has already been seen with this program in the reduction of sulfur dioxide emissions.

No greenhouse gas emissions here! http://www.westislandweather.com/wind_turbine_aalborg.jpg

We can also decrease the amount of greenhouse gases in our atmosphere currently to slow global warming. One relatively easy way to do this is Carbon Sequestration, which is the taking in and storing of Carbon Dioxide. Trees do this naturally through photosynthesis, so we should plant more trees and cut down less. This can also be done using technology, which basically capture the Carbon Dioxide as it exits the power plant and stores it underground.

Global Cooperation is also a must when it comes to reducing greenhouse gases because the whole world has to be willing to participate, not just one country. International treaties and regulations have already been implemented such as the regulations involved in the Kyoto Protocol. Unfortunately the United States is no longer a member of the Kyoto protocol for economic reasons.

So you may be asking what can I as an individual do? You can use “green” buildings with solar roofs or green roofs, alternative energy sources like wind, hydrogen powered vehicles, invest in green companies, and stop eating meat. (Less demand for beef=less cattle=less methane)

Just because it's hydrogen powered, doesn't mean it has to look silly. http://jch-picsontheweb.site88.net/web_images/red-hot-hydrogen-car.jpg

Here is a hilarious cartoon about the United States’ absence from the Kyoto Protocol:

http://trendsupdates.com/wp-content/uploads/2009/04/kyoto-protocol-cartoon.jpg

At the end of class on Friday Mr Willard left us with 5 questions regarding global climate change. These questions were as follows:

1. Is the Earth warming?

2. If so, is this warming unnatural?

3. If it is unnatural, is it anthropogenic (human-caused)?

4. What might happen as a result of this climate change?

5. What can and should we do to fix this?

Then in class on Monday we discussed the views of the Intergovernmental Panel on Climate Change (IPCC) on this subject and tried to answer some of these questions. So is the Earth warming?  According to the IPCC yes, the global average temperature has increased by 0.74 degrees Celsius, which is approximately1.3 degrees Fahrenheit, over the past 100 years.  This may not seem like a drastic change but this number is only a global average. It is important to note that in some places the climate is changing very little and in other there is a much more rapid climate shift.  For example arctic temperatures have risen twice as fast as the rest of the world over the past 50 years. Another fact that is evidence of global warming is the temperature records as of recent.  Since  1861, when temperatures were first recorded, the 5 hottest year are record were 2005, 1998, 2002, 2003, and 2006.

Ok so there is definitely evidence supporting that the Earth is warming, but is this warming unnatural?  According to the IPCC temperature and carbon dioxide levels in the troposphere are “beyond normal range” and paleoclimatic records show an “unnatural increase in temperature and carbon dioxide over the past 50 years”.  This graph illustrates Carbon Dioxide levels in the atmosphere and Global Temperature over the past 1000 years.

The next question regarding global warming is, Is this unnatural climate change our fault?  Once again the  IPCC says that global climate change is indeed anthropogenic.  Since the Industrial Revolution there has been a drastic increase in 3 of the 4 major greenhouse gases, and these are Carbon Dioxide (CO2), Nitrous Oxide (N2O), and Methane gas.  All of these gases have increased due to human activity.  The main causes of CO2 increase is the burning of fossil fuels and land use change.  Land use change in this situation most directly means deforestation.  Deforestation is a major problem because it destroys one of the planets natural carbon sinks.  A carbon sink is is a place that stores carbon such as CO2.  When you cut trees that usually store carbon more carbon in the form of CO2 is released into the atmosphere. Another acticity  that we as humans do to cause an increase in greenhouse gases is agriculture, and this causes increases in methane and N2O levels in the atmosphere.

Last Friday, we discussed the origins of global warming. However, climate change is a more accurate term since some regions are cooling, not warming.

First off, it must be established that not all greenhouse gases, like water vapor, CO2, CH4 and N2O are “bad.” In fact, without the natural greenhouse effect earth would be very cold, thus uninhabitable, but the natural greenhouse effect makes the Earth warm enough to sustain life. Essentially, when solar radiation reaches Earth’s surface, some is absorbed by land and water, but a good portion is reflect as infrared radiation. Greenhouse gases trap IR, causing warming in the troposphere. Take a look at this diagram:

http://www.ncrlc.com/01-GCC_imgs/figure03.jpg

However, there are several anthropogenic, or human-caused increases in greenhouse gases, such as fossil fuel use, deforestation, and agriculture. This “unnatural greenhouse effect” contributes to global warming, whose effects include but aren’t limited to an increase in average temp, glacier retreats, and severe weather events like hurricanes due to higher ocean temps. However, global warming gets political when people feel forced to relinquish their Hummers on the bases of hypothetical “what if” situations surrounding global warming, such as rising sea levels and their resulting population shifts. So when did all the hype about anthropogenic causes of climate change begin?

Origins of Climate Change:

It’s important to note that Al Gore didn’t invent “Global Warming.” In reality, research on the relationship between increased CO2 levels from the Industrial Revolution and higher temperatures began in 1896 by chemist Svante A. Arrhenius. For more on the history of climate change research, see http://www.npr.org/templates/story/story.php?storyId=10307560.

One important chemist, Charles Keeling, is known for his study of temperature and CO2. His results yielded the Keeling Curve, which “launched the current debate over what to do about rising greenhouse gas levels.”

http://sio.ucsd.edu/keeling/images/Keeling_Curve.jpg

Today, research illustrates with near certainty that average temperatures in the troposphere are increasing. But as for the debate over whether climate change exceeds the natural cycle of warming and cooling, or if human activity is causing climate change, many argue that more research is needed before any decisive conclusions are formed. As with all scientific questions,  the question of why the Earth is warming falls somewhere on the spectrum of certainty. In order of least to greatest certainty are: hypothesis, theory, and finally law. With increased data and observation, a hypothesis can either be supported or refuted.

To commemorate Earth Day PDS 5th grade teachers and students made signs to carry around the Ferry Boat reminding parents to turn cars off while in line picking up their children. They also modified the “stop and go” signs to reflect the No Idling initiative for all  teachers on traffic duty to carry. LS plans to launch the full program in the fall.

Cut off those engines!

Kids trying to educate parents

Today in class, we continued talking about the secondary effects of car exhaust and coal burning.  Today we spent the day talking about the formation/affects of acid rain in particular.

Acid rain in a problem in the troposphere, and is therefore a regional problem.  Even though acid rain has always been referred to as “rain,” a more appropriate term is Acid Deposition, or, to deposit acid.  This is because not all acid comes from rain.  There are two types of acid: Wet Acid and Dry Acid.  Wet acid comes from any form of precipitation that involves water, be it snow, rain, sleet, or fog.  Dry acid is the deposit of particles of acid (dusts or salts).  Whether the acid coming from the sky is wet or dry, it is always considered acid when it is more acidic than natural rain water (has a lower pH than 5.6).

Acid Rain is created (indirectly) when sulfur dioxide and nitrogen oxides are emitted into the atmosphere.  These gases can be emitted through the burning of coal, and from the use of gasoline-burning cars.  After the gases are emitted into the atmosphere, they react with the water droplets in clouds and in the air, creating a series of different reactions.  Here are three naturally occuring reactions that form acid rain: SO2+H2O=H2SO3; SO3+H2O=H2SO4; and 2NO2+H2O=HNO3+HNO2.  After reactions occur, acid falls from the sky in either the form of wet or dry acid deposition.  Here is a visual of the acid rain process:

http://www.odec.ca/projects/2008/shar8a3/AcidRain_drawing.gif

The effects of acid rain are detrimental.  Acid rain directly affects plant and animal tissue, dissolving away protective membranes.  It also directly affects monuments and buildings by breaking them down and dissolving them quicker than the natural decomposition rate.  Acid rain also lowers the pH of lakes and streams.  Indirectly, acid rain leaches soil of its vitamins and minerals, leading to lack of nutrition for plants.  It also “frees” heavy metals, and mobilizes them, which leads to fish suffocation when the heavy metals enter a pond or stream.  A final indirect affect of acid rain is the decay of the waxy membrane coating the surface of leaves on plants.  This leaves the plant more susceptible to freeze, dry up, or get killed by insects.  Here is an affect of acid rain:

a

http://www.solcomhouse.com/images/800px-Acid_rain_woods1.jpg

There are two major solutions for acid rain: Prevention and Clean Up. Acid rain can by prevented by burning low sulfur coal, washing and treating coal before use, using scrubber technology on power plants, using the cap and trade industry, and by using and burning less sulfur in gas.  Clean up of acidic rain is much more expensive, and one of the main ideas is to add lime to lakes, in order to make the lake less acidic.

I hope this helped!

*Note: This is a guest post from Alice G. in 8th period since I forgot ask for a scribe!

Your car breathes in from the air and the fuel tank and it breathes primary pollutants out, which then are converted into secondary pollutants. The central reaction in your car starts with the reactants in the air (78% N2, 21% O2), and the fuel tank feeds fuel to the engine.

However, the reactions in your car are not this simple, so there are many primary pollutants that come out of your car–some non-regulated (CO2, H2O, N2) and some regulated (CO, NOx, HC/hydrocarbons/VOC/Volatile Organic Compounds, SPM/Suspended Particulate Matter/Smoke) as shown in the diagram below. The important thing to note about NOx is that it is a precursor to O3. When NO2 reacts with sunlight, it forms NO+O. Then O goes on to react with O2 to form ground-level ozone, which is harmful to human’s lungs and plants.

Photochemical Smog (Secondary Pollutant) Formation

The secondary pollutants are produced from a further reaction of primary pollutants emitted from the car’s exhaust, including photochemical smog which was mentioned above. There are two types of smog, outlined below:

Mr. Willard's outline of two types of smog. This lesson focuses on photochemical smog.

Notice the difference in color between the Photochemical Smog on the left produced from car emissions and the Coal/Industrial Smog on the right.

Smog in Los Angeles

Smog in China

_____________________________________________________________

http://www.bynon.cc/blog/atmosphere.jpg

In class, we dicussed what made up “good air” and how it was defined.

First things first, we talked about how in Environmental Science, we mostly focus on the troposohere and the stratosphere. There are several differences between the two, but they both hold very important roles in providing “good air”

Trophosphere vs. Statosphere

Trophosphere = the air we breathe, where weather occurs, and is made up of 78% Nitrogen, 21% Oxygen and 1% “other” (more about that later), global warming, and the danger of ozone at this level.

Stratosphere= global winds and higher levels of O3, ozone thinning an issue, ozone= global sunscreen-necesary to block UV rays.

Overall, air in the trophosphere is comprised of 78% Nitrogen, 21% Oxygen and the 1% “other” made mostly of Co2, methane, water vapor and argon. Too much of one of these gases causes what we call “bad air”.