GEL 205: The Oceans and Climate Change

As sea ice melts and becomes liquid water, __________ heat is then absorbed from the Sun, creating warmer surface waters.

- more

Excess carbon taken up by the ocean can be contained in which of the following reservoirs?

**

Which of the following are true of Earth's eccentricity?

**

By how much has the pH of the ocean changed since the Industrial Revolution?

- - 0.1 pH unit

According to the data shown in the SmartFigure, what is the natural range of atmospheric carbon dioxide concentration over the past 800,000 years?

- 180-280 ppm

What was the concentration of carbon dioxide, in parts per million (ppm), in the pre-industrial period?

- 280

In John Martin's experiments in the 1990s, by how much was iron fertilization of the oceans shown to increase phytoplankton productivity?

- 30 times

How much of the Sun's incoming radiation is scattered or reflected back to space before any heating effect is felt on Earth?

- 31%

According to the data shown in the SmartFigure, what is the natural range of atmospheric methane concentration over the past 800,000 years?

- 350-750 parts per billion (ppb)

Every year, ____ gigatons of carbon are added to the atmosphere and ____ gigatons of carbon are added to the ocean.

- 4, 2

How much of the Sun's incoming radiation is absorbed by Earth's surface?

- 45%

If the "best case" scenario is followed, what will the approximate carbon dioxide concentration and global temperature increase be by the end of the century?

- 500 parts per million (ppm); 1°C

If the "business as usual" scenario is followed, what will carbon dioxide concentration and global temperature increase be by the end of the century?

- 850 parts per million (ppm); 4°C

What has analysis of ice cores revealed about atmospheric greenhouse gas levels during the historic period?

- A sudden rise in greenhouse gas levels coincides with the start of the Industrial Revolution

Which scenario on the SmartFigure shows the "business as usual" scenario?

- A2

The opening of Drake Passage about 41 million years ago caused a fundamental reorganization of ocean currents leading to the isolation of ________, which caused it to become much cooler.

- Antarctica

What percentage of the Earth's surface is composed of water?

- Approximately 70 percent of the Earth's surface is composed of water

Which of the following is the smallest reservoir of the carbon cycle on the Earth?

- Atmosphere

What would happen to Earth's atmospheric temperature if the amount of incoming shortwave radiation from the Sun decreased and was less than the longwave radiation lost to space?

- Atmospheric temperature would decrease

What would happen to Earth's atmospheric temperature if the amount of shortwave radiation reflected at Earth's surface increased significantly?

- Atmospheric temperature would decrease

What would happen to Earth's atmospheric temperature if the amount of outgoing longwave radiation decreased so that it was less than incoming shortwave radiation from the Sun?

- Atmospheric temperature would increase

What would happen to Earth's atmospheric temperature if the amount of shortwave radiation reflected by clouds decreased significantly?

- Atmospheric temperature would increase

What would happen to Earth's atmospheric temperature if the amount of incoming shortwave radiation from the Sun was the same as the longwave radiation lost to space?

- Atmospheric temperature would remain the same

What is the primary cause of the nearly 20 percent increase in atmospheric carbon dioxide levels since the 1960s?

- Burning of fossil fuels

How can carbon dioxide be released into the atmosphere?

- By burning fossil fuels

Which greenhouse gas is the most powerful in terms of how heat is absorbed by one molecule of the gas?

- CFC-12

Which reaction below correctly illustrates why the ocean is becoming more acidic?

- CO2 + H2O = H2CO3 = H+ + HCO3-

What did the results of NASA's SOIREE Experiment show?

- Chlorophyll concentrations in the surface ocean were higher in the areas of the ocean where iron was added

How might global warming affect cities that rely on glacial runoff for their water supply?

- Cities may face long-term water shortages as the amount of water generated by glacial melt will decline as glaciers shrink

How have vast forests on Earth influenced the greenhouse effect?

- Forests have reduced the greenhouse effect by removing carbon dioxide from the atmosphere

Where on Earth are the Keeling atmospheric carbon dioxide concentrations measured?

- Hawaii

Which of the following are examples of positive climate feedback loops?

- Ice melt in the Arctic - The addition of water vapor into the atmosphere - Heat uptake by the oceans

What is the cause of the recent spikes in atmospheric carbon dioxide and methane concentrations?

- Industrial Revolution

What greenhouse gas is released into the atmosphere as a result of raising domestic livestock such as cattle?

- methane

Which of the following statements is/are true regarding the basis of the iron hypothesis?

- Iron is typically the limiting nutrient to productivity in areas of the ocean with low productivity. - Primary productivity in the ocean removes carbon dioxide from the atmosphere. - Global warming would be more pronounced without the role of tropical rainforests

What evidence is there that the O'Higgins Glacier is being affected by global warming?

- It has retreated nine miles in the past 100 years because of melting

What is notable about the Keeling curve?

- It shows the annual variations in atmospheric carbon dioxide concentrations - It shows that carbon dioxide levels recently surpassed 400 parts per million (ppm), the highest level on record - It is the longest continuous historical record of directly measured atmospheric carbon dioxide concentrations on Earth, going back to 1958

Which of the following is the largest reservoir of the carbon cycle on the Earth?

- Lithosphere

How does the atmosphere of Mars differ from that of Earth?

- Mars has less gravity which prevents it from holding onto most gases that comprise the atmosphere

Most of the world's water is found in two locations. The first is the world's oceans. Where is the second location, the one with most of the world's freshwater?

- Most of the world's freshwater is locked in the ice at the poles

How do the oceans contribute to maintaining a climate that is habitable for humans?

- Oceans absorb large quantities of carbon dioxide from the atmosphere

Which organisms are most sensitive to ocean acidity, and why?

- Organisms with hard parts composed of calcium carbonate, because calcium carbonate dissolves in acidic seawater

What is causing a decline in Antarctica's Chinstrap penguins?

- Populations of the penguin's major food source are declining because of melting sea ice

Which of the following are true of Earth's precession?

- Precession is caused by the wobble of Earth's axis as it spins like a top Currently, the Northern Hemisphere winter occurs when Earth is closest to the sun - Currently, the Northern Hemisphere summer occurs when Earth is farthest from the sun

What impact will increased carbon dioxide absorption by the oceans have on coral reefs?

- Reefs will degrade over time, ultimately resulting in large-scale mortality

What impact would rising sea levels have on human migration?

- Rising sea levels would cause enormous migration as people move inland away from affected areas.

Despite the general stability of the Thermohaline Conveyor at present, future climate changes could alter the temperature and salinity dynamics of the world's oceans amidst rising sea levels, thereby leading to more extreme weather events. What do most scientists point to as the cause for the projected rise in sea level and extreme weather?

- Scientists have projected higher sea levels and increases in extreme weather in the coming decades as a result of estimated future global emissions of greenhouse gases, primarily CO2.

How do snow and ice on the surface of Earth affect Earth's climate?

- Snow and ice reflect incoming solar radiation

What is the fate of the carbon dioxide that is removed from the atmosphere by marine phytoplankton?

- Some is released back into the atmosphere once the organism dies and is decomposed. - Some is buried on the seafloor as organic carbon and carbonate. - It is used by the phytoplankton to build their shells and bodies

Which of the following statements correctly identify a mechanism by which two spheres interact?

- The biosphere and atmosphere interact through forest fires. - The hydrosphere and atmosphere interact through evaporation and precipitation. - The geosphere and atmosphere interact through volcanic eruptions

Which greenhouse gases have natural sources as well as human-caused sources?

- methane - nitrous oxide - carbon dioxide

Which of the organisms below are directly affected by ocean acidity?

- mollusks - coccolithophores - sea urchins - pteropods - corals

Which of the following statements regarding the role of clouds in Earth's climate is/are correct?

- The increase in clouds in a warming climate acts as a negative feedback by reflecting more sunlight, making it cooler. - The increase in clouds in a warming climate acts as a positive feedback by trapping more heat, making it warmer. - The decrease in clouds in a cooling climate acts as a positive feedback by trapping less heat, making it cooler. - The decrease in clouds in a cooling climate acts as a negative feedback by reflecting less sunlight, making it warmer.

There is one master ocean current that is also the drive belt of our weather systems. What is this current called?

- The master ocean current is called the Thermohaline Conveyor

What is causing the oceans to become more acidic?

- The oceans have absorbed about 30% of the carbon dioxide released by humans into the atmosphere

How will increases in atmospheric carbon dioxide levels affect oceans?

- The oceans will become more acidic

Which of the following are true of Earth's tilt?

- Tilt reaches its maximum every 41,000 years - Tilt is also referred to as obliquity - Greater tilt leads to more extreme seasons on Earth

Why are scientists doing research in an underwater lab in the Great Barrier Reef?

- To replicate future carbon dioxide levels and measure the changes in coral reef productivity, mortality and health

Which layer of the atmosphere has the greatest mass and contains nearly all of the Earth's water vapor?

- Troposphere

Of the following natural factors, which have caused past climate changes on Earth?

- Volcanic eruptions - Plate tectonics - Changes in solar energy - Variations in Earth's orbit

Which of the following statements regarding Earth's natural climate variations is/are correct?

- When carbon dioxide concentrations are higher, methane concentrations are higher - Natural variations include the Medieval Warm Period and the Little Ice Age - Recent spikes in carbon dioxide and methane are not a part of Earth's natural climate cycle

Where did the carbon dioxide and methane data in the SmartFigure come from?

- air bubbles in ice cores from Antarctica

Which of Earth's spheres are humans a part of?

- biosphere

What process moves carbon from the lithosphere to the atmosphere?

- burning of fossil fuels

Which greenhouse gas is currently contributing the most to increasing the greenhouse effect?

- carbon dioxide

Scientists use complex computer models to predict scenarios for future climate change. Which of the factors listed below is/are included in the climate models?

- clouds and climate feedback loops - human population increases and economic changes - anthropogenic greenhouse gas emissions

Which of the following statements is/are an example of a negative feedback loop?

- cooling temperatures leading to decreased cloudiness and leading to warming - warming temperatures leading to increased cloudiness and leading to cooling

What is the result of a positive feedback loop?

- cools the climate even more after an initial cooling - warms the climate even more after an initial warming

The minimum area of Arctic sea ice cover has been __________ as air and water temperatures have been __________ over the past several decades.

- decreasing; increasing

Arctic sea ice naturally __________ during the dark, cold winters and __________ during the spring and summer.

- expands; contracts

What is the main cause of the increase in carbon dioxide seen in the Keeling curve?

- humans burning fossil fuels

Which of Earth's spheres make up the climate system?

- hydrosphere - geosphere - biosphere - atmosphere - cryosphere

Combustion of fossil fuels results in a transfer of carbon from the ____________.

- lithosphere to the atmosphere

Which of the following lists Earth's carbon reservoirs from largest to smallest? For deep-sea sediments, assume an average value.

- lithosphere, hydrosphere, cryosphere, biosphere, atmosphere

Which combination of eccentricity and precession would best support a glacial period?

- maximum eccentricity and precession such that the Northern Hemisphere summer occurs at aphelion

Which set of orbital parameters would result in the coldest Northern Hemisphere winters?

- maximum tilt, maximum eccentricity, and precession such that the Northern Hemisphere winter occurs at aphelion

The concentration of which greenhouse gas is currently increasing at the fastest rate?

- methane

The Keeling curve is now supplemented by additional data from measurement sites around the world and by satellite data. According to the AIRS Mid-Tropospheric Carbon Dioxide NASA satellite data shown in the SmartFigure video, where on Earth are the most dramatic increases in carbon dioxide observed? (Shown in red.)

- off the northeast coast of North America - off the northeast coast of Asia

Arctic sea ice reached a historic minimum in 2012 that was approximately __________ the size of the long-term average recorded during 1979-2000.

- one-half

Only some shortwave radiation from the Sun reaches Earth's surface. What is the leading cause of this radiation loss?

- reflection by clouds

Which of the following is not used for collecting data about Earth's climate?

- sedimentary rocks

What does scenario A1B require?

- shift from fossil fuel-based economies to renewable energy-based economies - implementation of new fuel-efficient technology

What is the primary driver of Earth's climate?

- solar radiation

What causes the sawtooth pattern in atmospheric carbon dioxide concentrations?

- summer and winter, when vegetation naturally absorbs and releases carbon dioxide

The ocean's "biological pump" __________

- takes carbon from the photic zone and stores it in deep ocean water and seafloor sediments

How is energy transferred from Earth's surface to Earth's atmosphere?

- through the greenhouse effect - through convection - through latent heat in water vapor - through conduction

Which of the following statements is/are an example of a positive feedback loop?

- warming temperatures leading to increased water vapor in the atmosphere and leading to additional warming - cooling temperatures leading to decreased evaporation rates, leading to less water vapor in the atmosphere and further cooling

What is the result of a negative feedback loop?

- warms the climate after an initial cooling - acts to keep the climate steady and balance it against change - cools the climate after an initial warming

Why has iron fertilization not been widely adopted as a solution to global warming?

-Iron fertilization can exacerbate ocean acidity - Iron fertilization can create dead zones