Climate & Climate Change

How are polar bears affected by reduced amounts and decreased duration of sea ice?

They are negatively affected since they do most of their hunting of seal from sea ice.

The graph illustrates that diseases caused by organisms such as mosquitoes ______ as temperatures rise.

are more common

Earth is absorbing about ______ watts per square meter per year more from solar radiation than it is radiating back to space.

0.85

Sea level would rise approximately ______ if the West Antarctic ice sheet would completely melt.

5-6 meters

Deep layer

A layer of cold (< 5οC), slow-moving, rather isolated water

Middle layer

A layer where temperature changes rapidly with depth

What set of conditions below represents an El Niño event?

A warm pool of water moves across the Pacific toward South America, limiting upwelling.

Which of the following are clear evidence of past climate change?

Coal deposits found under glacial deposits Dunes that formed in a desert are now covered in vegetation. North Africa switching from a wheat-growing region during the Roman Empire to being a desert at the empire's end.

Surface layer (top 100 to 200 meters)

Contains the most vigorous circulation, is well-mixed, and averages about 15οC

An increase in cold freshwater runoff into the oceans

Cooling due to more carbon dioxide being absorbed from the atmosphere

An increase in the cloud coverage

Cooling due to more sunlight being reflected

Identify anomalies related to or caused by El Niño-Southern Oscillation events (Select all that apply.)

Droughts in areas that normally receive rain Changes in the timing and intensity of monsoons Heavy rains and landslides along the Pacific coast of North America

A(n) ______ event occurs when upwelling is suppressed off the west coast of South America because a warm pool of surface water moves eastward across the central Pacific.

El Niño

What is the main role of thermohaline circulation with respect to global climate?

It transports a lot of heat around the earth.

What would be the consequences of the complete melting of the West Antarctic ice sheet? (Select all that apply.)

It would be extremely expensive to deal with the results. Many coastal cites and ports would be flooded.

____________ is a more powerful greenhouse gas than carbon dioxide and is produced by the decay of organic matter and by the digestive processes of many livestock. It also is released when fossil fuels are extracted and used.

Methane or CH4

Identify the offshore areas where upwelling events are especially frequent. (Select all that apply.)

Off the west coast of North America Off the west coast of Africa Off the west coast of South America

Which of the following statements accurately compares modern levels of atmospheric carbon dioxide (CO2) levels to the concentrations recorded in ice cores over the last few hundred thousand years?

The atmospheric carbon dioxide (CO2) levels are higher now.

Why have levels of greenhouse gases been increasing in earth's atmosphere?

The burning of fossil fuels to power our technology has added large amounts of greenhouse gases to the atmosphere.

Which of the following are sources of atmospheric methane? (Select all that apply.)

The digestive process of many domestic livestock Some forms of natural decay of organic matter

What is the major shift that happens during El Niño/La Niña events?

The frequency, intensity, and locations of storms change in various regions of the world.

What process keeps earth's surface much warmer than it would be otherwise, thus allowing life as we know it to exist?

The greenhouse effect

What does research suggest is the relationship between global warming and the intensity of hurricanes?

The intensity of hurricanes is likely increasing as hurricanes are driven by heat absorbed from the ocean's surface.

What evidence do we have that global warming is already having an effect on ice? (Select all that apply.)

The majority of alpine glaciers are receding. The extent of sea ice is decreasing in the Arctic region.

What is an La Niña event?

The opposite of an El Niño event in that unusually cold surface waters exist off of western South America

Which statement below accurately states the current balance between the amount of incoming solar radiation received by earth from the sun and the amount of energy radiated back to space?

There is a small net excess of energy being absorbed.

What are the consequences of melting sea ice on sea level?

There is no effect on sea level.

Why are natural greenhouse gases needed by life as we know it?

They help keep earth much warmer than it would be without them.

Which of the following statements accurately describe upwelling? (Select all that apply.)

Upwelling water tends to be cold and nutrient-rich. Fishing tends to be good in upwelling zones.

A decrease in albedo (reflectivity)

Warming due to an increase in thermal radiation from earth's surface

An increase in evaporation

Warming due to more water vapor absorbing outgoing longwave radiation

Surface waters can be described as warm and well mixed. The layer under the surface is a zone where temperatures ______ until the deep layer is reached, where temperatures ______.

decrease rapidly; are stable but near freezing

Alpine glaciers are receding and Arctic polar ice is thinning and shrinking in areal extent. This is evidence that ______.

global warming is already having an effect on ice

Because of the proxy data recovered from ______, we know that over the last few hundred thousand years, the temperature has changed substantially by spanning a range of 10οC, the climate has warmed rapidly at various times, and there is a correlation between greenhouse gases and temperature.

ice cores

Because hurricanes obtain their energy from warm ocean water, we expect that warmer ocean temperatures will ______ the intensity of hurricanes.

increase

Thermohaline circulation ______.

involves cold, sinking, saline water is a deep water current transports deep water nearly around the globe is driven by density differences

If surface winds result in the top layer of water moving offshore, deep water may ______ to replace the displaced water.

upwell

What frequently occurs along the west coasts of North and South American and Africa that results in good fishing grounds?

upwelling

Warm, wet air moves into the ______ Pacific during a La Niña event. This results in conditions in which unusually ______ surface waters exist off western South America.

western; cold