ENVS 1401
Exam #5
Please write clearly and legibly; what I cannot read I cannot grade.
{If you finish early, just relax. All papers will be collected at ~noon}
1) The first law of energy is sometimes summarized, as "you can't get something for nothing." The second law is summarized, as "you can't even break even." Please explain what these phrases (and the 2 laws of energy) mean. [10 points]
The first law of energy says that energy can neither be created nor destroyed, just changed in form. This tells us that the quantity of energy present on earth at any moment in time is constant and we cannot get more energy from a system than we put into it.
The second law of energy says that the transformation of energy from one form to another is not a very efficient process and that this transformation occurs with the evolution of low-quality energy such as heat. So as one transforms energy to a more useful form, it is not possible to be 100% efficient and some of the energy we start with is wasted and ends up in a form that we don't want or need, usually heat.
2) a) Where had the Exxon Valdez been and where was it going as it moved through Prince William Sound ?[5]
It had just loaded itself with crude oil from the trans-Alaskan pipeline at the port of Valdez and was heading to Los Angeles to a refinery.
b) Describe what happened next and how and why it occurred.[5]
The Exxon Valdez ran aground on a reef, punctured its hull and spilled a significant portion of the crude oil it was containing, fouling beaches, the water and harming wildlife.
c) What lessons were learned from the Exxon Valdez incident?[5]
Several lessons include how important it is to be prepared for a spill and have help available. Response should be prompt and the oil spill contained as best as possible. Using extraordinary tactics such as scouring the beaches with high-pressure hot water may be more disruptive than helpful. The crew of such ships should be well-trained to run the ship. Adequate personnel should be available so crews do not become exhausted. There are lots of others.
3) a) What is a fossil fuel and how is it formed?[5]
A fossil fuel is a nonrenewable natural resource, such as crude oil, natural gas or coal produced by the decomposition and compression or organic matter from ancient life.
b) List three environmental impacts of fossil fuel production and consumption [5]
Burning fossil fuels pollutes the atmosphere and leads to acid deposition.
Coal mining destroys habitat and pollutes rivers and streams.
Combustion of fossil fuels increases the CO2 in the atmosphere influencing global climate.
There are lots of others.
4) What specific impacts does each of the following pollutants have on our health and the health of our environment? Please be specific. [15 points]
a) Lead
Lead is an environmental hazard because it is a nerve poison. It also causes miscarriages, high blood pressure, behavioral problems and loss of IQ in youngsters.
b) thermal pollution
Thermal pollution is caused by hot water being dumped into cooler water such as lakes and ponds. It lowers the oxygen level of the water and stresses fish and other forms of aquatic life.
c) endocrine disruptors
An endocrine disrupter is a class of chemical that mimics the body’s hormones. Examples are pesticides and herbicides such as DDT and atrazine. These can have profound impacts on animals’ reproductive functions.