Unit 11 Blog

Discussion Topics:

Connections Discussion:

We discussed in class today that everything is connected (remember Joe's pond and Johnson's run??)  One of the main concerns about the increased carbon dioxide emissions is that they are linked to an increase in global temperature, rising sea levels and increased oceanic carbon dioxide concentrations.  These three things can have cascading effects on many different ecosystems globally.  Follow the link to the National Wildlife Federation website to read more information on how coral reefs are being negatively impacted by these global changes.  NWF- Coral Reefs  First, discuss the topics below in relation to the coral reef (the link should take you right there) then pick one other animal/plant/ecosystem from the menu on the left side and discuss in relation to your choice.  
Why is this animal/plant/ecosystem important?  Explain at least two ways that this animal/plant/ecosystem is directly impacted by increased atmospheric carbon dioxide, make sure to describe any negative effects these environmental changes have on coral reefs/your pick and the primary source of the carbon dioxide emissions.  What kind of economic impact does this have and what conservation efforts are being made to reduce the destruction?

Coral reefs are ecologically important because they are extremely biodiverse and act as a breakwater for adjacent coasts which helps make sure coastal ecosystems aren't too severely disrupted. Higher sea temperatures cause bleaching which often results in the death of the corals; the ecosystem predicated upon the coral subsequently dies off as well.  (and subsequent fx)

Increased atmospheric carbon dioxide also causes ocean acidification which makes it hard for calcification of corals to occur; this slows growth and means the ecosystem can't grow as fast as well. Global warming fueled by carbon dioxide emissions are the main source of these changes and the main source of global carbon emissions are the burning of fossil fuels. The destruction of coral reefs severely harms tourism industries as coral reefs are a huge tourist attraction and instrumental in fishing. Conservation efforts include restricting ocean dumping, improving watershed restrictions, reducing fossil fuel use, and an education campaign. 

The Great Lakes are a huge source of freshwater, home to many species, and key to many recreational activities. Global warming caused by increased levels of atmospheric carbon dioxide may reduce water levels as less winter ice coverage means a higher chance of evaporation. Lower water levels are detrimental to species living in the lakes as they have less space to live, to humans using the lake for drinking water, and to entrepreneurs who have set up businesses along the current lakeshore. The resulting higher water temperatures are also detrimental to species that may not be able to survive at higher temperatures and because the higher temperatures can change the internal cycling of water in the lakes resulting in more hazardous algal blooms and larger areas of hypoxia. The primary source of CO2 emissions which fuel global warming is fossil fuel consumption. An economic impact of receding shorelines and higher water temperatures is that the tourism industry takes a hit as businesses formerly on the lakeshore can no longer advertise that feature as an attraction and there are less fish for which to go fishing. There are restoration projects, movements to limit water usage, and decrease the causes of global warming to conserve the Great Lakes.

Ozone Discussion
I can't say it enough, ozone is awesome and horrible all at the same time!  It's essential for life in the stratosphere but damaging in the troposphere!  In this discussion piece, I basically want you to summarize everything you know about ozone at each level!  Discuss the negative human health effects of both tropospheric (too much)  and stratospheric (not enough) ozone.  Describe the closed-loop chemical reactions associated with the formation and breakdown of stratospheric ozone (if you can find pictures or diagrams, feel free to insert here).  Explain how other compounds, particularly CFCs, interfere with these chemical reactions (again, a diagram would be helpful).  Finally, explain the role of tropospheric ozone in the formation of photochemical smog (diagrams, why not??  You chose how you want to convey your message as long as you understand what you are talking about).

Tropospheric ozone is harmful to plants and humans; it can cause respiratory inflammations such as asthma and emphysema in humans. It can also react with nitrogen oxides and VOCs to from even more harmful oxidants, including smog. Stratospheric ozone helps limit exposure to harmful UV-B and UV-C rays which can cause the deterioration of DNA and tissue damage, often leading cancer, sunburn, and cataracts. Too little stratospheric ozone results in increased exposure to these harmful rays. Normally, the formation and breakdown of ozone is a closed-loop reaction where UV-C breaks apart O2 into 2 O which then react with O2 to produce O3; UV-B and UV-C rays break apart the bonds in O3 to form O2 and O which can then reform to once again block UV rays. 

CFCs and other compounds such as NOx and CCL4 interfere by breaking apart O3 into ClO and O2 and then freeing itself to react with more ozone (like a catalyst) as ClO reacts with O to produce Cl and O2.

Tropospheric O3 is involved in the formation of photochemical smog as it combines with NO to from NO2 and O2 but if VOCs are present, they bind to the NO which makes it unable to break down tropospheric ozone. 

Positive and Negative Feedbacks
Obviously climate change can be a hot topic to debate! Many arguments for or against global warming are based off of the idea that our actions will continue the cycle and magnify the situation (positive feedback) OR that the earth will correct the issue because ultimately a cycle will slow down or stop the process on its own (negative feedback).  Provide an argument for and against global climate change by giving and example of both a positive and negative feedback can increase or decrease the impact of climate change.  There are examples of this in your text, but I would encourage you to seek out other sources to see if you can find one that we have yet to discuss in class!  

An example of a positive feedback loop for climate change is that higher temperatures will cause the permafrost to melt; as anaerobic decomposition occurs under the new pools of standing water, methane will be produced which will contribute to the greenhouse effect. A negative feedback loop would be the stimulated plant growth as a result of higher temperatures and increased CO2 concentrations removing CO2 from the atmosphere and storing the carbon in organic matter. 

BIG Picture Discussion
This is where you will make the four BIG PICTURE connections to the ENTIRE UNIT. Please tie in information you learned in your reading (chapters 15 and 19) and from the notes in class. There is not an exact length that I am expecting other than it should definitely be at least a paragraph for each section, should be thorough and show understanding of the topic.  Remember to be specific in your examples.  Do not just say "there are laws that govern this" or "people destroy the Earth."  Give me the names of the laws, what they regulate and who enforces them.  Tell me what humans are doing to destroy the earth. 

Human Impact-  Air pollutants such as asbestos, sulfur dioxide, and carbon monoxide severely harm human health by causing cancer, respiratory disease, and death. Tropospheric ozone is harmful to humans and causes asthma and emphysema while stratospheric ozone helps protect humans from UV-B and UV-C rays that can cause cancer and cataracts. Global warming can cause the loss or gain of food crops depending on the climate change that occurs in specific regions and can also dehydration, heatstroke, and an increased use of fossil fuels as air conditioning or heating systems become more necessary. The warming climates may also change the range of disease and expose more humans to more harmful diseases. Humans cause many of these impacts through industrial and agricultural processes and waste products, especially fossil fuel consumption and the use of CFCs which are entirely anthropogenic.

Environmental Impact-  Increased atmospheric carbon dioxide can cause increased plant productivity, increased decomposer activity in soils, melting glaciers which results in habitat loss and rising sea levels, a loss of biodiversity, changing weather patterns which may also change the distribution of species, increased storm intensity, and ocean acidification, one result of which is coral bleaching. Decreased ozone levels in the stratosphere damages plants resulting in less photosynthetic activity and will also increase the exposure of organisms to damaging UV-B and UV-C rays. 

Economic Impact- Coral bleaching and the warming of climates suitable for snow sports can harm tourism industries as they become less attractive for the activities they were previously known for. Increased carbon dioxide levels increase plant productivity which could have a beneficial effect on the agricultural sector, especially as climates warm and more land becomes agriculturally viable. Rising sea levels can flood coastal cities which would harm local economies; this is also true of increased storm intensity as storms can wreak havoc on communities which then must rebuild and/or relocate. Rising temperatures of water and acidification may affect fishing industries as common fishing species are unable to adapt the new conditions, or their food sources die off or migrate elsewhere which would in turn cause the predators to die or migrate elsewhere. 

Government Legislation-

Legislation involved with global warming includes the Kyoto protocol, which is an agreement to reduce greenhouse gas emissions globally though the US didn't sign it. The Clean Air Act in the US allows the EPA to regulate carbon emissions. The Montreal protocol was an international agreement that limited the use of and eventually banned CFCs. Al Gore, Clinton's secretary, did sign the Kyoto Protocol when it was still in its early stages but the Senate never ratified it rendering the signature insignificant. The Senate still has yet to pass it anytime it comes up; they cite doubt of the effects of climate change and the unfairness in not penalizing developing countries as reasons not to sign. The National Ambient Air Quality Standards in the US allow the EPA to monitor air pollutants.