Chapter 4- Climate Change

If plants or animals today need certain conditions to live, then similar organisms also required those things.

What is pollen?

Every type of plant has a particular type of pollen.

Why do scientists collect pollen data?

It can tell scientists about ancient climate.

How do tree rings form?

It forms every year, when a new layer of wood forms a ring.

What can scientists infer from the tree ring data?

They can see whether previous years were wet or dry and warm or cool.

What is an ice age?

Cold periods also known as glacial periods.

What occurs during an ice age? When was the last ice age?

Glaciers covered much or Europe and North America. The last one was 10,500 years ago.

What causes climate change?

Variations in Earth's position, changes in sun's energy output, volcanic eruptions, and movement of continents.

How does Earth's position as it rotates around the sun increase the chances of an ice age?

The angle at which the Earth's axis is tilted and when Earth is closest to the sun can cause ice ages.

What are sunspots?

Dark, cooler regions on the surface of the sun.

What happens when the sun produces more energy? How does this affect Earth's temperature?

More energy may cause Earth to warm.

How can volcanic activity cause climate changes?

The ashes and gases from the volcano filter out solar radiation and lower temperatures.

How can movement of the continents cause the climate to change?

The global patterns of wind and ocean currents, which slowly changes climate.

What are the two short-term changes caused by ocean currents and wind?

El Nino and La Nina, caused by changing of ocean currents and prevailing winds.

Explain what happens during an El Nino. Where does it begin? Where does it travel to? What does an El Nino do to the cold ocean currents?

Begins when an unusual pattern of winds forms over the Pacific. It moves eastward toward South American coast. Disrupts cold ocean currents and changes weather patterns there.

How long can El Nino last?

Can last for one to two years.

Explain what happens during a La Nina. What kind of weather does a La Nina bring?

When surface waters in Pacific are colder than normal. Brings colder than normal winters and precipitation.

What is global warming?

The gradual increase in the temperature of Earth's atmosphere.

What are greenhouse gases?

Gases that trap energy.

What is the greenhouse effect?

The trapping of heat from gases near the Earth's surface.

What is the hypothesis scientists have created to explain Earth's increasing temperatures?

That human activities add greenhouse gases to the atmosphere.

Why has the level of carbon dioxide increased in the atmosphere?

As an effect of global warming, because it is a greenhouse gas.

What is another hypothesis by scientists to explain the increase of Earth's temperatures?

They think it may be part of natural variations in the climate.

What are the possible effects of global warming?

Farmers could plant two crops a year, fertile fields would turn into dust bowls, warm ocean water (and cause more hurricanes), and raise sea levels and melt glaciers.

How can depleting the ozone layer affect humans?

An increase in ultraviolet radiation could occur, which can cause eye damage and cancer.

What are chorofluorocarbons?

Groups of compounds that ruin the ozone layer.

What is the result of the ozone layer being depleted?

CFC's will be eliminated.

What is climate?

Average, yearly conditions of temperature.

What is a microclimate?

A small area with a different climate from the areas around it.

What are the factors that affect temperature?

Latitude, altitude, distance from water and ocean currents.

What are the climates near the equator like?

Warmest climates

What is latitude?

The distance from the equator

What is the tropical zone?

The area near the equator

What kind of sunlight does the tropical zone receive?

Direct or nearly direct sunlight

What is the sunlight like at the north and south poles?

Sunlight strikes at a lower angle, so the climate is colder.

What are the polar zones? What latitude will you find the polar zones?

The polar zones are the areas near the north and south poles, from 66.5 and 90 degrees north or south

What are the temperate zones?

The area between the tropical and polar zones

What is the sunlight like in the temperate zones? In winter? In summer?

Sunlight strikes more directly in the summer, and at a lower angle in winter.

What factor is responsible for the difference between the climate at the mountaintop and the climate at the base?

The altitude of the mountain

What are marine climates?

Areas on west coasts that have mild winters and cool summers.

How does water heat up compared to land? How does water cool down at night compared to the land?

Water heats up and cools down slower than land.

What are continental climates? Where are they located?

More extreme temperatures in central U.S, Canada, and Russia. Winters are cold and summers are warmer.

How do ocean currents affect climate?

Warm ocean water warms the air above and it moves over land.

What kind of weather does the Gulf Stream bring? Where does it begin and travel to?

It begins in the Gulf of Mexico and travels along the east coast of the U.S. It brings mild, humid air.

What kind of weather does the California Current bring? Where is it located?

It flows south down the west coast and brings cooler temperatures

What are the factors that affect precipitation?

Prevailing winds, the presence of mountains, and seasonal winds.

What are prevailing winds?

Directional winds that blow in a specific region.

How do the prevailing winds across oceans or lakes compare to winds traveling across land?

Winds that blow across oceans carry more water vapor, and winds across lands carry less.

How do mountain ranges affect the path of prevailing winds?

When humid winds blow from the ocean, they rise and form clouds over mountains, and create precipitation.

What is windward?

The side of a mountain the wind hits

What has happened to the air that has moved over the mountains?

It lost it's water vapor, so it's cool and dry.

What is leeward?

Downwind side of the mountain.

What are monsoons?

Sea and land breezes over a large region that change direction with the seasons.

What causes monsoons to form?

When land gets warmer than the ocean, which makes humid air blowing from the ocean to rise and condense into clouds.

What causes the different seasons?

The tilt of Earth's axis around the sun.

What is the axis of Earth titled at?

An angle of 23.5 degrees.

How is the northern part of Earth pointed in June?

The north end is tilted toward the sun, making it summer.

How are the northern and southern hemispheres affected in September?

Both hemispheres receive the same amount of sun energy.

How is the southern part of Earth affected in December?

It is tilted toward the sun, making it summer.