Exam 15: The Earths Changing Climate

Carbon dioxide concentrations in the atmosphere have been increasing steadily since the beginning of the industrial revolution and may double before the end of the current century.Why is this of concern?

Evidence suggests that throughout much of the earth's history,the global climate was:

A positive feedback mechanism:

The Milankovitch cycles in association with other natural factors explain how glaciers may advance and retreat over periods of hundreds of millions of years.

Assume that you have 100 years of continuous temperature records from your local weather service office.Discuss some of the difficulties you might have trying to determine whether average temperatures have increased during this period.

Presently glaciers cover less than 1% of the earth's surface.

Which of the following is not true?

Explain how analysis of glacial and polar ice cores provide important clues about past climate.

Studies reveal that during colder glacial periods,CO₂ levels were lower than during warmer interglacial periods.

Which of the conditions below would most likely produce warming at the earth's surface?

The Milankovitch Theory proposes that climatic changes are due to particles suspended in the earth's atmosphere.

The much-studied temperature record of the past 140 years is derived from land-based observations only.

The earth has been in a warming trend for

Large volcanic eruptions with an ash veil that enters the stratosphere,tend to __________ at the surface.

What combination of the earth's orbital eccentricity,and precession and obliquity of the earth's axis would produce hottest summer temperatures in the Northern Hemisphere?

Asia and the North American continent have been connected by a land bridge at various times during the past.When was the Bering land bridge most recently exposed? Did this coincide with a warm or cool climatic period?

What are some of the possible consequences of global warming?

If the earth were in a cooling trend,which process below would most likely act as a positive feedback mechanism?

Volcanoes that have the most impact on global climate seem to be those rich in:

Describe some of the techniques used to infer past climates.About how far into the past are these different methods able to reconstruct past climatic conditions?