Problem: Factories around the world produce lots of CFCs which deplete the ozone layer. One year a large number of these factories decided they would implement efforts to reduce the amount of CFCs they release into the atmosphere. As a result the depletion of the ozone layer greatly decreased. However, the companies realized that this was hurting profits too much and reverted their decision. As a result the ozone layer began to rapidly deplete again. Given the ozone layer starts to deplete much faster than before, has the amount of CFCs released into the atmosphere increased or decreased? Hint: Beginning in the late 1970's, ozone depletion was recognized as a significant environmental issue. The most dramatic decrease in ozone occurs seasonally over the continent of Antarctica. The size and duration of the ozone hole steadily increased, with the largest hole recorded in 2006. Fortunately, most countries have recognized the danger of CFCs and dramatically curtailed their use in recent years. It is hoped that ozone depletion will slow and that the ozone layer may eventually be restored to its earlier levels.

A: increased

Problem: Tim and Allen were two pen pals, Tim lived in Canada, while Allen lived in Australia. they were chatting about the weather and the fact that their two countries are situated in two different hemispheres. Which person experiences warmer weather in January, Tim or Allen? Hint: During May, June, and July, the Northern Hemisphere is exposed to more direct sunlight because the hemisphere faces the Sun. The same is true of the Southern Hemisphere in November, December, and January. It is Earth's axial tilt that causes the Sun to be higher in the sky during the summer months, which increases the solar flux. However, due to seasonal lag, June, July, and August are the warmest months in the Northern Hemisphere while December, January, and February are the warmest months in the Southern Hemisphere.

A: Allen

Problem: Both Alabama and Florida boast great wetlands. The State of Alabama has experienced extensive drainage system due to expansion of farmlands. Their neighboring state Florida had similar system. But recently Florida had dismantled many of their drainage systems, mostly because of pressure from different environmental groups. Would Florida lose or retain habitat of different species? Hint: Ecologically, the expansion of drainage systems has had tremendous negative effects. Hundreds of thousands of wetland species experienced significant population declines as their habitat was increasingly fragmented and destroyed. Although market hunting within the Central Flyway was a contributing factor in the decline of many waterfowl species' numbers in the early decades of the twentieth century, loss of breeding habitat to agricultural expansion is certainly the most significant. Early maps of midwestern states depict many lakes and marshes that are either nonexistent or significantly reduced in area today. Channelization, a related process of concentrating and facilitating the flow of water from agricultural areas, also contributed to this degradation.

A: retain

Problem: Two geologists studied the Earth's crust. Benny studied mantle melting, while Vinny studied more about crust displacement. Which scientist observed more volcanoes forming? Hint: Mantle melting can come about three ways: (1) when the temperature rises, (2) if the pressure lowers (which lowers the melting point), and (3) if water is added, which lowers the melting point. Two of these (1 and 3) might explain why there are volcanoes at convergent plate boundaries the temperature of the subducting plate increases as it sinks into the hot mantle (1). Sediments lying on top of the subducting plate contain water. As the sediments subduct, the water rises into the overlying mantle material. This lowers the melting temperature of the mantle (3). When the mantle above the subducting plate melts, volcanoes form above it. This leads to volcanoes in an island arc or continental arc.

A:
Benny