55 terms

test yourself chapter chapter 13


Terms in this set (...)

A biogeophysical feedback mechanism in the Sahel relates ____.
reduced vegetation to a decrease in surface temperatures and a reduction in rainfall
A high concentration of oxygen 16 found in the ice caves of Antarctica and Greenland would indicate ____ at the time the ice was formed.
cold air temperatures
A positive feedback mechanism ___
Additional clouds in a warmer world ____
An increase in atmospheric CO2 concentrations will most likely lead to ____ in the troposphere and ____ in the upper atmosphere.
warming; cooling
Climate models predict that if average global temperatures rise, both global precipitation and drought will ____
During a period when the earth's orbital tilt is at a minimum, what would most likely to occur?
During the climatic optimum, ____.
the climate favored the development of certain plants
During the Little Ice Age, ____.
alpine glaciers grew in size and advanced
During the Pleistocene epoch, ____.
Everything else being equal, a gradual increase in global CO2 would most likely bring about ____.
an increase in surface air temperature
If the earth were in a cooling trend, which process below would most likely act as a positive feedback mechanism?
increasing the snow cover around the earth
If the earth were in a warming trend, which of the processes below would most likely act as a negative feedback mechanism?
increasing the snow cover around the earth
It appears that, as the number of sunspots increases, the sun's total energy output ____.
increases slightly
It is now known that, overall, clouds ____.
have a net cooling effect on climate
It now appears that if global temperatures continue to rise, the oceans ____.
could increase or reduce the amount of CO2 in the atmosphere
Large volcanic eruptions with an ash veil that enters the stratosphere, tend to ____ at the surface.
decrease temperatures
Over the past 100 years or so, it appears that average global temperatures have ____.
increase slightly
Ozone is a greenhouse gas that ____ role in the enhancement of the greenhouse effect.
plays a minor
Plate tectonics "explains" certain climatic changes by showing that these changes may be related to ____.
mountain building
the position of the continents
the paths taken by ocean currents
Precession of the equinox refers to ____.
the wobble of the earth on its axis
Presently, ice sheets and glaciers cover ____ of the earth's surface.
about 10 percent
Studies reveal that during colder glacial periods, CO2 levels ____ during warmer interglacial periods.
were lower than
The "year without a summer" may have been caused by ____.
particulate matter and gases from volcanoes
The "year without a summer" occurred in ____.
The CLIMAP project was able to reconstruct the earth's ocean surface temperature in the past by examining ____.
thousands of feet of sediment at the bottom of the ocean
The higher the ratio of oxygen 18 to oxygen 16 in the shells of organisms that lived in the sea during the geologic past, the ____ the climate at that time.
The Maunder Minimum refers to a time when ____.
there were fewer sunspots
The Milankovitch cycles in association with other natural factors explain how glaciers may advance and retreat over periods of ____.
ten thousand to one hundred thousand years
The Milankovitch Theory proposes that climatic changes are due to ____.
variations in the earth's orbit as it travels around the sun
The Milankovitch theory suggests that climates changes on the earth could be caused by changes in ____.
the shape of the earth's orbit around the sun
the direction of tilt of the earth's axis
the amount of tilt of the earth's axis
The most recent North American glaciers reached their maximum thickness and extent ____.
about 18,000 to 22,000 years ago
The most recent warming trend experienced over the Northern Hemisphere could be the result of ____.
increasing levels of greenhouse gases
The Sahel ____.
is a region of variable rainfall
The Viking colony in Greenland perished during the ____.
Little Ice Age
Volcanic eruptions that have the greatest impact on global climate appear to be those rich in ____.
Warming at the earth's surface will most likely occur when there is an increase in the amount of ____.
high-level global cloud cover
Which of the following decades was the warmest on record?
Which theory explains how glacial material can be observed today near sea level at the equator, even though sea level glaciers probably never existed there?
theory of plate tectonics
Climate models predict that oceans will warm more rapidly than landmasses in the northern high latitudes during the next 100 years.
Recent evidence suggests that the variations in the earth's orbit around the sun proposed by Milankovitch actually have very little effect on the earth's climate.
Some scientists believe the earth is in a comparatively warm part of an ice age.
The combined effect of trace greenhouse gases (such as methane (CH4), nitrous oxide (N2O), and CFCs) in enhancing the greenhouse effect is about equal to carbon dioxide.
Warm ocean water cannot contain as much dissolved carbon dioxide as cool ocean water.
Maunder minimum
This refers to a time when there were few sunspots
radiative forcing agent
Any factor that can change the balance between incoming energy from the sun and outgoing energy from the Earth
year without a summer
Another name for the year 1816
conveyor belt
The circulation of ocean water that can play a role in rapid climate change
Ice Age
Another name for the Pleistocene epoch
positive feedback mechanism
When an initial process is reinforced by another process it is referred to as this
carbon dioxide
This greenhouse gas occupies about 0.040 percent in a volume of air, and may more than double in concentration over the next 100 years or so
The study of annual growth rings of trees
An increase in the desert conditions of a region
water vapor
The most abundant greenhouse gas
A time, about 11,000 years ago, when North America and northern Europe reverted back to glacial conditions