Problem: Two researchers looked at the human influence on atmospheric carbon dioxide levels. Tim studied a human settlement from 10000 years ago, while Bob studied a present day county. Today's economy in the county revolved around extensive agriculture.  Which researcher found more evidence of land clearing?  Hint: Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because these activities reduce the number of autotrophic organisms that use up carbon dioxide in photosynthesis. In addition, clearing often involves burning, which releases carbon dioxide that was previously stored in autotrophs.

A: Bob


Problem: Two teams of runners took part in a study about exercise. Red team ran 10 km in the heat, while Green team ran the same distance in the morning in cool weather. The Red team experienced more runners with health problems.  Which team had fewer runners with muscle weakness?  Hint: Millions of people in the world jog for exercise. For the most part, jogging can be a healthy way to stay fit. However, problems can also develop for those who jog in the heat. Excessive sweating can lead to electrolyte loss that could be life-threatening. Early symptoms of electrolyte deficiency can include nausea, fatugue, and dizziness. If not treated, individuals can experience muscle weakness and increased heart rate (which could lead to a heart attack). Many sports drinks can be consumed to restore electrolytes quickly in the body.

A: Green


Problem: Due to an increase in the number of factories releasing carbon dioxide the concentration of it has increased. Recent reports show a correlation between increasing levels of carbon dioxide and the average global temperature increasing.  Will releasing more carbon dioxide cause the average temperature to increase or decrease?  Hint: Current Situation : Currently the heating effect of extra greenhouse gases (since the start of the industrial revolution) is equal to about . Thus the recent period has recorded parallel increases in concentration of carbon dioxide and average global temperature. As more greenhouse gases are put into the atmosphere the temperature will increase further. There are certain effects of a warmer Earth (discussed more in optional section), which could accelerate the process, even if no more greenhouse gases are put into the atmosphere (an unlikely prospect for the foreseeable future).

A: increase


Problem: Jimmy is currently shopping at his local grocery store during his weekly trip to get food and other necessities. He first picks up some frozen pizzas, his favorite meal when he is feeling lazy after work, and then stops off to pick up a loaf of bread. He then walks over to the dairy section to pick up some cheese for his lunches. Jimmy never buys milk, but today he has a sudden urge to get some. He walks over to the milk refrigerators and looks at all the options. He is currently debating between two brands, Luchene and Jean's. While trying to decide, he notices a sticker on the Luchene gallon that says "organic," but is unable to find any such indication on the gallon of Jean's milk. After asking an employee, it is confirmed that Jean's is not organic milk. Unable to make up his mind, Jimmy simply leaves without buying any milk.  Which brand requires more cows to produce the same amount of milk?  Hint: Compared to conventional milk production, organic milk production tends to have lower eutrophication potential per ton of milk or per hectare of farmland, because it potentially reduces leaching of nitrates (NO3−) and phosphates (PO4−) due to lower fertilizer application rates. Because organic milk production reduces pesticides utilization, it increases land use per ton of milk due to decreased crop yields per hectare. Mainly due to the lower level of concentrates given to cows in organic herds, organic dairy farms generally produce less milk per cow than conventional dairy farms. Because of the increased use of roughage and the, on-average, lower milk production level per cow, some research has connected organic milk production with increases in the emission of methane.Animal welfare issues vary among dairy farms and are not necessarily related to the way of producing milk (organically or conventionally).

A:
Luchene