Geo-science Semester 2

New technology has allowed us to genetically modify our food. Scientist can now create crops that are pest resistant, drought resistant, faster growing and more nutritious. These consequences would best be described as

positive, intended consequences.

According to the World Resource Institute, biodiversity is the variety of the world's organisms, including their genetic diversity. In a world of genetically modified (GM) crops, agriculture is greatly reducing the genetic diversity of the plants on Earth. If we ignore genetic diversity while we develop GM products, we risk a disease or pest emerging that will wipe those types out. One answer to this problem is seed banks. Storage of material in the form of seeds is one of the most widespread and valuable ex-situ approaches to conservation. All BUT ONE is an advantage of seed banking over other ex-situ methods of biodiversity conservation. That is

seed banks are expensive to maintain.

The La Brea tar pits, located in California, contain a wealth of fossilized organisms that lived between 25,000 and 40,000 years ago. Columbian mammoths, sabertoothed cats, bison, wild horses, and land sloths are just some of the herbivores that have been trapped in the asphalt seeping from the interior of Earth. These herbivores were primarily grass eaters. Fossilized plant remains of live oaks, cedar trees, sagebrush, and grasses have also been discovered. Fossils found in the La Brea tar pits indicate a California climate that was

similar to today's climate

When we use renewable resources with care, ensuring that they are not depleted for future generations, we are following a practice called

sustainability.

Conservation methods are needed worldwide for many reasons. All but one is a reason to support conservation.

undiscovered lands will provide plenty of natural resources

There are several models of the carbon cycle. Which model shows the causes and amounts of carbon flux into and out of the cycle?

graph with factory on left side

Burning of fossil fuels has changed the atmosphere by

increasing the concentration of carbon dioxide.

The hypothetical scenario on Earth could be the result of

massive volcanic eruptions.

Carbon dioxide is returned to the atmosphere primarily by the

respiration of consumers

Refer to the information above. Which petroleum product is used as a lubricant in engines?

motor oil

The ocean's biological carbon pump is driven by organisms that live in there. Just like the terrestrial carbon cycle, the oceanic biological carbon pump is all about photosynthesizing, respiring, eating, producing waste products, dying and decomposing. The biological pump plays a major role in all BUT ONE of the processes involved in oceanic carbon cycling.

upwelling currents bringing deep, cold ocean water to the surface to warm and release carbon back to the atmosphere.

Refer to the information above. Which of the following statements about fossil fuels is false?

Most of the energy used in the U.S. comes from sources other than fossil fuels.

If a decision is made to create a landfill, what would be considered a disadvantage?

attracts animals and insects

It is projected that an increase in carbon dioxide levels in the atmosphere will MOST LIKELY lead to

higher-than-average sea levels.

Solar energy is renewable. What could be an economic factor that prevents the maximum exploitation of this resource?

olar energy is not always available and needs to be stored.

Refer to the information above. Which petroleum product is used to create toys and kitchen utensils?

plastic

Prior to the Industrial Era, pre-1780, ____________ affected Earth's climate because they emitted both aerosols and carbon dioxide into the atmosphere.

volcanoes

_____________ is the variety of life on Earth, on both the species and genetic levels.

Biodiversity

Refer to the information above. Which petroleum product is used to warm homes, schools, and workplaces?

heating oil

The causes of climate change can be divided into two categories: natural and human causes. The natural variation of the climate has always been part of Earth's history. It is now a great concern that the climatic changes occurring today may be the direct result of man's activities. All BUT ONE is a natural cause of climate change.

increased greenhouse gases

Intensive eradication efforts and declining numbers of prey, bison, elk, and white-tailed deer in the south; moose, deer, caribou, and beaver in the north, caused the wolf declines in the western Great Lakes area. Bounties paid for dead wolves began during the 1800's. By 1838, wolves were eliminated from the southern portion of Michigan, by the early 1900's they were eliminated from southern Minnesota and Wisconsin, and by 1960, wolves were also gone from northern Wisconsin and Michigan, except Isle Royale, and from most of Minnesota. Over the last 50+ years, efforts have been made to recover the wolf populations mentioned here. As seen in the data table, those efforts appear to be working. Recovery of the wolf population in mentioned states has several facets. They include all but

monitoring of an epidemic of canine parvovirus.

Refer to the table above. Which of these statements cannot be proven by the data shown here?

World population will continue to increase through 2010.

Reducing the emissions of which gas will lead to reducing the greenhouse effect?

carbon dioxide

Hydrological power harnesses energy through the movement of water in rivers. Which statement represents an added benefit to this renewable energy resource?

creates water reserves

Computer simulation is becoming a commonly used process to efficiently model and evaluate the impact of a variety of proposed solutions when facing a complex real-world problem. Such computer simulations are particularly beneficial in situations where actually carrying out full trials of proposed solutions would be all except:

too cheap

There have been many different periods of glaciation, the process of covering the Earth with glaciers or masses of ice, throughout the history of the Earth. The most recent of these events is known as the last glacial period. How many years ago is it approximated the last glacial period reached it maximum ice coverage?

18,000 years ago

Sam's neighbors were worried too. Although the community has built the fence you see here, this feature in no way solved the erosion problem. Extensive community discussion as well as consulting with an environmental engineering firm resulted in a step-by-step conservation plan that included all but ONE of the steps listed here.

Build a cement and stone seawall inland of the shoreline.

Refer to the graph above. Which of these provides the largest percentage of energy used in the United States?

petroleum

What technological advances had positive impacts on diet and food distribution systems, but also had an adverse effect on the atmosphere when the system malfunctioned?

refrigerator

Carbon dioxide diffuses into the ocean carbon cycle via the air-sea surface exchange. Molecules of CO2 enter the ocean by diffusing into the surface waters and dissolving. The amount of CO2 that diffuses and dissolves in the surface water depends on several variables. Scientists have noted that sea more CO2 diffuses and dissolves in colder sea surface water and less CO2 diffuses and dissolves in warmer water. Let's assume the predictions of scientists predicting a warming climate are true. Can you predict the outcome if average ocean temperatures increase as well? Include the effects on appropriate components of the biosphere as well as the hydrosphere.

Warmer oceans would mean less dissolved CO2 as well as other gases such as oxygen in the global ocean. Lower CO2 would result in a decrease in photosynthesis of autotrophs living in the oceans.

1815 is know as the Year Without a Summer. This catastrophic event is the largest of its kind in the last 10,000 years. It produced snowfalls throughout the summer months of June, July, and August in the New England states and Europe. Grain and corn crops failed; people starved. Alpine glaciers advanced far down mountain slopes; sea ice moved far from the polar regions and disrupted shipping. The events of 1815 were caused by

a massive volcanic eruption.

Refer to the table above. If the trend shown by the data continues, predict levels of atmospheric carbon dioxide by 2005.

between 370 and 380 parts per million

Plastic debris are a major source of marine pollution, endangering many marine mammals, birds and fish. Computer simulations are being used to analyze the redistribution and accumulation of this material. What factor, in addition to the mass, buoyancy and persistence of these materials, would be critical in studying their motion?

ocean circulation

Refer to the information above. Which of the following statements about fossil fuels is false?

ood is an example of a fossil fuel.

Foresters recently noticed an apparent drop in the squirrel population in a near-by oak-hickory forest. The squirrels eat acorns produced on the oak trees; hawks eat squirrels. The foresters are not sure what is causing the decline in the squirrel population but they are concerned that both the squirrel and hawk populations will disappear. How could they best find an answer to their question?

Use a computer simulation model of the potential forest populations

The diagram below illustrates a natural Earth process through which the atmosphere traps heat. Many scientists hypothesize that human activities are accelerating this process, resulting in a global warming trend. What human activity is believed to have an adverse effect on the natural process pictured here?

burning of fossil fuels

Climate change is a significant, long-lasting distribution of weather patterns over periods ranging from decades to millions of years. Which does not contribute to climate change?

ozone hole

Refer to the graph above. What percentage of energy used in the U.S. is supplied by renewable resources?

15

Your family is building a house in the mountains. Although you are not building off-the-grid, you and your family are committed to building and running your new home as well as living in your home as sustainably as possible. Your parents both work from home so they will need Internet access. Your community does not have any means of public transportation. You are committed to developing a plan that is reasonable for the area in which you live so that once your home is completed you and your family may live sustainably. Your plan might include all BUT ONE of these tactics.

Buy bottled water for drinking and cooking to reduce the amount of water you take from local sources.

Copper is a metal that is used for many purposes. It is mined from the earth using various methods. Though the amount of copper in the Earth's crust is very large, if the mining of copper continues, it will eventually run out. All BUT one method listed below will help conserve the world copper supply. Which method might actually increase copper mining?

the development of a cheaper and more efficient way to mine for copper

The mangrove tree is an important foundation species in estuarine and coastal forests. When mangrove trees are removed, it results in a rapid build-up of acid sulfides in the soil and increases shoreline erosion. What is a LIKELY impact of removal of mangroves from their habitat?

Inshore breeding areas would be affected and aquatic species would decline.

What two processes fuel the carbon cycle

cellular respiration and photosynthesis

Volcanic eruptions, changes in Earth's orbit, meteorite impact, and even the combustion of fossil fuels ALL contribute directly or indirectly to climate change by

changing the amount of solar radiation that reaches Earth.

In a pond, the pollution of water by human-made pollutants, such as oil and grease, can cause chemical, biological, and ecological changes. As plants begin to die and decompose, carbon dioxide is released. What would happen to the fish in the pond?

the fish would die off

Carbon is a major component of all organic compounds, including carbohydrates, lipids, proteins, and nucleic acids. Carbon dioxide is continually exchanged between the atmosphere and oceans. What geological process returns carbon to the atmosphere in the form of carbon dioxide?

volcanic activity

Conservation. The choices in the list above help to regulate important biogeochemical cycles as well as conserve important natural resources. Making these good choices impacts several cycles on Earth. Which set of answers - biogeochemical cycle; natural resource; consequence - is not a effected by the the list above?

water; water; Oxygen enters the waterways and causes an imbalance of plant life to animal life.

One example of cost/benefits analysis is building a railroad system. In general, the viability of such a project is the benefits derived from improved transport minus the costs of building the railroad. However, almost inevitably, additional constraints and/or trade-offs within such a project also require consideration and prioritization to determine the actual benefits derived and costs incurred. Additional costs associated with safety, reliability, and desired aesthetics as well as possible social, cultural, and environmental impacts are often presented by interested parties for consideration regarding the overall value of the project. A difficult aspect of cost benefits analysis as more of these additional constraints and trade-offs become involved is the ultimate decision on the project becomes too _____________.

subjective

According to data collected by the EPA, for a period of approximately 2,000 years there was little change in the global average sea level. The global average sea level rose throughout the 20th century, and the rate of change has accelerated in recent years. When averaged over all of the world's oceans, absolute sea level has risen at an average rate of 0.06 inches per year from 1880 to 2013. Since 1993, however, average sea level has risen at a rate of 0.11 to 0.14 inches per year, about twice as fast as the long-term trend. Why is a change in sea level important? As the temperature of the Earth changes, so does sea level. Explain how changes in Earth's temperature have a direct result on sea level. All BUT ONE answer is correct.

Earth's continents rise and fall relative to the oceans. Land can rise through geological uplift and sedimentation. It can sink due to erosion, sediment compaction, or natural subsidence.

Oceans play an important role in determining climate change. Ocean circulation affects the climate through the atmospheric concentration and movement of _________ into or out of the atmosphere.

carbon dioxide

As shown on the map, Norway and Southern Greenland on the same latitude (60° N). Why is Norway warmer than Southern Greenland in winter?

Ocean currents carry heat toward Norway, but not toward Greenland.

A balance between incoming and outgoing radiation produces a stable climate. Lack of a balance between incoming and outgoing radiation results in a net loss or gain of radiant energy to the system. This energy imbalance is expressed as climate change. What are the basic steps in this system of energy input and output?

Solar radiation reaching the Earth system and being absorbed, thermal radiation emitted by the Earth system.

According to the USGS, volcanoes release less than 1% of the carbon dioxide released currently by human activities. While it has been proposed that intense volcanic release of carbon dioxide in the geologic past did cause global warming and possibly some mass extinctions, this is a topic of scientific debate. Yet volcanoes DO influence our climate and following a huge eruption, the effects can be felt almost immediately. Although carbon dioxide is released during a volcanic eruption, another gas plays a much bigger role in climate change, and rather than warming the climate it helps to cool the climate. Use the model to explain how this cooling effect takes place.

Sulfur dioxide emitted into the stratosphere combines with water to form sulfuric acid aerosols. This makes a haze of tiny droplets in the stratosphere that reflects incoming solar radiation, causing cooling of the Earth's surface

Scientists have used computer models to create a series of maps that show how susceptible coastal cities and island countries are to the sea rising at different levels. The maps show that a 1-meter rise would swamp cities all along the U.S. eastern seaboard. A 6-meter sea level rise would submerge a large part of Florida. Thermal expansion has already raised the oceans 10 to 20 centimeters. The MOST likely cause, directly and indirectly, for such a rise in sea level is

global warming.

Refer to the information above. Which petroleum product is used as a road surfacing material?

asphalt

A period of prolonged continental glaciation often indicates which phenomenon?

An ice age.

Refer to the graph above. Which statement about the sources of energy used in the U.S. is true?

Petroleum, coal, and natural gas supply 85% of U.S. energy needs.

According to the theory of global warming, which statement is the MOST LIKELY reason for the current climate change?

The atmosphere is reradiating more heat to Earth.

If Earth's atmosphere did NOT contain any water vapor, the temperature of the earth's surface would

be significantly lower.

Global warming is caused by an increase in the level of carbon dioxide gas in the atmosphere. How has this affected the world's ocean

The oceans are absorbing the excess carbon, causing the oceans to become acidic.

The oceans of the world are considered to be carbon sinks. A carbon sink is anything that absorbs more carbon than it releases as carbon dioxide. Besides being dissolved in the ocean waters, we can find carbon in many places throughout the oceans. Choice from the list above and select all of the places in the ocean that you would find carbon.

A. thru D.

The circle graph below shows the percentages of water which are used for various activities in the United States. Which statement about the use of water in the United States is false?

Industrial use of water is greater than the amount used to cool power plants.

Composting is the process of converting organic materials like plant material, food waste, and manure into humus. Humus is a soil-like material. There are many benefits that composting has for the environment. How does composting protect our ground water supply?

It reduces the need for artificial fertilizers.

The combination of dominant tree species in Eastern forests will likely change in the future. Some forest types, including spruce/fir and maple/beech/birch, may shrink significantly or disappear altogether, depending on how greatly carbon dioxide emissions increase in the future. How would you adapt your behavior to create a different scenario, on in which the was no substantial change in the tree species over time? All BUT ONE tactic would help.

Manage lands for restoration and watershed conservation.

As the number of ice-free days in the seas surrounding Alaska increases over time, so do opportunities. Oil and gas companies are increasing offshore exploration and drilling in the Arctic while the shipping industry is increasing traffic around and through the region. As a result, Arctic residents may have new opportunities for jobs and development across the region. The impacts of any oil spill is catastrophic and far-reaching to the area. Since 1980, data has been collected regarding the frequency and size of oil spill sin the area. What conclusion can you draw from the data collected?

Oil spills have been occurring since oil production began and are likely to continue to occur.

Large volcanic eruptions can have an almost immediate effect on Earth's climate. Rather than warming the climate volcanic eruptions helps to cool the climate. During the 1900's there were three large eruptions that caused the entire planet to cool down by as much as 1oC. Volcanic coolings persist for only 2 to 3 years because the released aerosols fall out of the stratosphere and enter the lower atmosphere where rain and wind quickly wash them away. Using the model, can you elaborate on the reason a volcanic eruption might cool the climate?

Sulfur dioxide emitted into the stratosphere combines with water to form sulfuric acid aerosols. This makes a haze of tiny droplets in the stratosphere that reflects incoming solar radiation, causing cooling of the Earth's surface.

Among all Michigan tree species, the jack pine is uniquely adapted to exist and reproduce on the hottest and driest sites in Michigan. It thrives on dune sand and on the sandy glacial plains. It is called a fire species because wildfires sweep through jack pine stands, killing the trees and preparing the ground for a new stand, as well as releasing seeds from its cones. Once in a while, lightning would start a fire that would be fanned into a raging fire leaving everything behind it blackened and burned. The destruction was only temporary. Soon the jack pine seeds would fall to the ground, and, in a few weeks, the area would be green with new growth. This process was repeated every 30 to 100 years, and the jack pine continued to dominate these fire prone areas. How did the periodic jack pine wild fires impact the inputs and outputs of the carbon cycle according to this model?

The jack pine fires cause a temporary drop in both photosynthesis and respiration.

Your family is building a house in the mountains. Although you are not building off-the-grid, you and your family are committed to building and running your new home as sustainably as possible. On a global scale, shelter is associated with about 25% of the greenhouse gas emissions and 26% of households' land use. You are committed to developing a plan while building that is reasonable for the area in which you live. Your plan might include all BUT ONE of these tactics.

You plan to buy only seasonal foods that are locally sourced in addition to growing your own.

Advances in oil drilling techniques have reduced the environmental footprint left by oil companies. Companies are now able to drain several oil fields from one platform using new techniques that allow more oil to be extracted from a single well. What is this advancement in oil drilling called that has substantially reduced the environmental impact of drilling?

horizontal drilling

Water conservation is not limited to conserving the amount of water available, but also considers the quality of the water available. The United States has come a long way in this area when compared to other countries. Which of the statements below is a water quality conservation method used in the United States?

sewage treatment plants

A study published in Science notes that water flowing from the Atlantic Ocean into the Arctic is warmer than it's been in 2,000 years. Scientists believe that this increased heat input has far-reaching consequences to life on Earth. U.S. and European scientists studied the Fram Strait branch of the North Atlantic Current, the ocean current that carries heat north from the tropics. By studying tiny-shelled organisms called foraminifera, found deep in the ocean floor, they could chart temperatures going back 2,000 years. From their findings, scientists reported that the water has warmed about 2° C since the late 1800s. The medieval ice age, or Little Ice Age (LIA) is defined by NASA as a cold period between 1550 AD and 1850. During this time cooling in the northern hemisphere by as much as 1° C has been postulated. How does the LIA research impact the study published in Science?

It gives context for some of the data.

When sunlight reaches the Earth's surface, the world's oceans absorb some of this energy and store it as heat. This heat is initially absorbed at the surface, but some of it eventually spreads to deeper waters. Currents also move this heat around the world. Water has a much higher heat capacity than air, meaning the oceans can absorb larger amounts of heat energy with only a slight increase in temperature compared to the solid parts of the Earth system. The total amount of heat stored by the oceans is called ocean heat content, and measurements of water temperature reflect the amount of heat in the water at a particular time and location. Ocean temperature plays an important role in the Earth's climate system. Explain how this slow but consistent rise in the ocean heat content seen above will influence Earth's climate.

Ocean heat content influences the ocean surface temperature. Heat from ocean surface waters provides the energy for storms and thereby influences weather patterns on Earth.

Hydraulic fracturing is a controversial method of extracting natural gas and other fuels from the earth. It has become very common in the United States and can increase the profitability of drilling dramatically. Which statement would opponents not cite as a reason to discontinue the process?

This technique can increase the amount of fuel recovered from a well.

A computer simulation is created to measure the impact of carpooling, creating a bus service and building a light rail system on the average commuting time for people in a small city. What would be an explanation for why the simulation would suggest that light rail would reduce commuting times most dramatically?

Trains carry more passengers reducing traffic on the roads.

Which of these events has led to the largest changes in worldwide sea levels?

glaciation

The human population reached 6 billion in 1999. In 2002, the rate of human population growth was 1.3 million people per year. Which of these conditions causes stress within the human population?

growth which is more rapid than can be handled by available resource

Carbon dioxide is constantly exchanged among the atmosphere, ocean, and land. Carbon dioxide is produced and absorbed by microorganisms, plants, and animal by natural processes which help maintain a natural balance. However, since the beginning of Industrial Revolution, human activities have contributed substantially to Carbon dioxide gases in the atmosphere. Identify the type of relationship found in the graphs of Global Carbon Emissions and Global Temperatures over the past 150 years.

positive nonlinear correlation

Shell-builders use calcium carbonate molecules (CaCO3) to build their shells. Which of the choices above could be a source for the carbon atoms in the calcium carbonate (CaCO3) molecules?

B. thru E.

Mining produces materials used in manufacturing all kinds of products, from consumer goods to fertilizers to energy supplies. During the 20th Century, per capita resource consumption rose 400%. Today, the production of goods and services requires, on average, over eighty tons of natural resources annually per person, including materials from mining. By 2050, that consumption of natural resources is expected to rise by an additional factor of three. Mining has a huge environmental impact including erosion, formation of sinkholes, loss of biodiversity, and contamination of soil, groundwater and surface water by chemicals from mining processes. Besides damage to the environment, the contamination resulting from leakage of chemicals can affect the health of the local populations. There are a number of ways to reduce the environmental impacts of mining. Consider the list here: All BUT ONE is a cost-free minimize the negative consequences of mining.

Companies and governments can be held accountable for abandoned sites and be required to carry out an environmental cleanup.

All energy resources have an impact on our environment. Fossil fuels do substantially more harm than renewable energy sources by most measures, including air and water pollution, damage to public health, wildlife and habitat loss, water use, land use, and global warming emissions. It is important to understand the environmental impacts associated with producing power from renewable sources such as wind, solar, geothermal, biomass, and hydropower. The type and intensity of environmental impact from each resource varies depending on the technology used, the geographic location, and several other factors specific to each resource. Harnessing wind power is one of the cleanest and most sustainable ways to generate electricity as it produces no toxic pollution or global warming emissions. Wind is also abundant and inexhaustible. But it has its disadvantages. All BUT ONE could be considered a disadvantage to using wind power as a sustainable energy resource.

Land use - Wind turbines can be sited on brownfields: abandoned or underused industrial land which significantly reduces concerns about land use.

The oceans absorb carbon through three processes that draw atmospheric carbon dioxide into the oceans: the physical carbon pump, the biological carbon pump and the carbonate pump. In which scenario would a carbon sink be the result of the physical carbon pump mechanism?

More CO2 is diffusing into sea surface water than is diffusing from sea surface water out to the atmosphere.

Biofuels - Both biodiesel and renewable diesel can be produced from plant or animal oils, fats, and wastes. According to the U.S. Energy Information Administration, the United States uses a combination of oils and fats in biodiesel production: soy oil 65%, corn oil 7.5%, and yellow grease and white grease was less than 8% of production of 8,478 million pounds of feedstock inputs for biodiesel in 2013. According to the latest published life-cycle analysis for various feedstocks and the feedstock mix reported by the Energy Information Administration and the U.S. EPA for 2013, the average GHG reduction for biomass-based diesel exceeds 80%. If biofuels provided a quarter of transport fuel in 2050, it would avoid an estimated 2.1 gigatons of GHG emissions per year. Although biofuels are among the few fuels for medium- and heavy-duty trucking that are considered renewable, there are some issues regarding its status as a sustainable fuel source. The sustainability of biofuels comes into question on several fronts. All BUT ONE is a reason why environmentalists question biofuels as sustainable energy resources.

Reduction in greenhouse gas emissions drastically reduces the carbon footprint of a combustible fuel.

Changes in climate influence ecosystems by altering animal behavior and ranges. Birds are a particularly good indicator of environmental change for several reasons: they are easy to count, each species has adapted to a certain habitat type, food source, and temperature range, and scientists believe that If a change in behavior or range occurs across a range of bird types, it suggests that a common external factor might be the cause. The graphic model illustrates the annual change in latitude of bird center of abundance for 305 bird species in North America from 1966 to 2013. The center of abundance is a point on the map that represents the middle of each species' distribution. If a whole population of birds were to shift generally northward, one would see the center of abundance shift northward as well.

The trend in the center of abundance moving northward can be related to rising average winter temperatures in North America.

Carbon dioxide is naturally present in the atmosphere as part of the Earth's carbon cycle. Human activities are altering the carbon cycle, by adding more CO2 to the atmosphere and by influencing the ability of natural sinks, like forests, to remove CO2 from the atmosphere. While CO2 emissions come from a variety of natural sources, human-related emissions are responsible for the increase that has occurred in the atmosphere since the industrial revolution. Consider the graph above. Notice the trend in atmospheric carbon dioxide as recorded at recording stations over Antarctica. Hypothesize how the schematic of the carbon cycle might change if urbanization and deforestation continues unchecked.

The photosynthesis carbon sink will decrease in gigatons; the carbon dioxide output due to combustion will increase.

Refer to the graph above. What two energy sources combined provide a greater percentage of energy than petroleum alone?

coal and natural gas

Natural global warming and cooling is initiated by Milankovitch cycles. Earth's orbital and axial variations influence the initiation of climate change in natural cycles of ice ages and warm periods (glacial and interglacial periods). The Milankovich cycles are caused by changes in the shape of the Earth's orbit around the sun, the tilt of the Earth's rotation axis, and the wobble of our axis. As Earth's orbit changes, so does the amount of sunlight that falls on different latitudes, during the seasons. When the northern summer sun is strong, the Earth experiences a warm period. When it is weak, an ice age. As we come out of an ice age, the sea level rises about 400 feet and we experience a warm period like the one we are in now. The natural cycle is brief warm periods followed by an ice age about every 100 thousand years Environmental agencies throughout the world believe that humans have forced Earth out of its natural cycle. Consider the choices below as possible sources of empirical evidence for anthropogenic climate change. Which choice does not support this view?

Graph that is in the color of orange and yellow

Unlike most bison in the West, which are managed as domestic livestock, Yellowstone's population has thousands of animals that all exhibit wild behavior like their ancestors. They are exposed to predators, severe environmental conditions, and show no evidence of any interbreeding with cattle. The Yellowstone bison are an essential part of a complex ecosystem that is much larger than the national park. It is the goal of the U. S. National Park Service to maintain this wild, migratory population of bison. Management of the bison population in Yellowstone National Park has several facets. They include all but

Hunting inside NP

A study published in Science notes that water flowing from the Atlantic Ocean into the Arctic is warmer than it's been in 2,000 years. Some scientists believe that this increased heat input has far-reaching consequences to life on Earth. U.S. and European scientists studied the Fram Strait branch of the North Atlantic Current, the ocean current that carries heat north from the tropics. By studying tiny-shelled organisms called foraminifera, found deep in the ocean floor, they could chart temperatures going back 2,000 years. From their findings, scientists reported that the water has warmed about 2° C since the late 1800's. An additional on-going study has been monitoring atmospheric carbon dioxide at the Mauna Loa Observatory. Atmospheric carbon dioxide contributes to the retention of radiation in Earth's atmosphere. The planet is warmer than it was in 1880. The disagreement comes over what is causing the rise. Global warming scientists believe the warming is caused by human activity. Skeptics believe the increase is due to in part to natural fluctuations. The Earth's land-sea surface temperature has not statistically increased since 1996. Global warming skeptics call it the great pause. In spite of a continuing, rapid rise in atmospheric CO2 concentrations since 1996, there has been no warming in the global instrumental temperature record. Community Digital News reports that every year that passes without the earth's surface temperature rising creates problems for scientists who argue that human activity is causing global warming. Regardless of which camp you belong to, consider the following situations. Throughout the world, scientists have noted that glaciers are (1) melting, (2) calving, and (3) not reforming to any extent. Additionally, the polar ice caps are shrinking. What effect would these occurances have on the human population?

The melting ice would cause a rise in sea level. That in turn, would cause coastal areas, some heavily populated to be flooded with sea water.

Chlorofluorocarbons (CFCs) are manmade chemicals found in some cleaning agents, aerosol cans, and foam packaging. These chemicals are known to destroy molecules of a gas which play an important role in the environment. This gas, found as a layer in the stratosphere, absorbs and filters out harmful ultraviolet radiation before it reaches Earth's surface. Which atmospheric gas is destroyed by CFCs?

ozone (O3)