2. Global warming
What's Going to Happen?
Natural and Amplified
Warming
Causes
3. refers to the current rise in
the average temperature of Earth's
atmosphere and oceans and its
projected continuation.
4. Average temperatures have climbed 1.4 degrees
Fahrenheit (0.8 degree Celsius) around the world since
1880.
Average temperatures in Alaska, western Canada, and
eastern Russia have risen at twice the global average.
5.
6. Glaciers and mountain snows are rapidly melting
—for example, Montana's Glacier National
Park now has only 27 glaciers,
versus 150 in 1910.
8. Coral reefs, which are highly sensitive to small
changes in water temperature, suffered the worst
bleaching—or die-off in response to stress—ever
recorded in 1998, with some areas seeing bleach
rates of 70 percent.
percent
9. An rise in the amount of extreme weather events, such
as wildfires, heat waves, and strong tropical storms, is
also attributed in part to climate change by some
experts.
10.
11. Sea level could rise between 7 and 23 inches (18 to 59
centimeters) by century's end.
Some hundred million people live within 3 feet (1 meter)
of mean sea level, and much of the world's population is
concentrated in vulnerable coastal cities.
12. Glaciers around the world could melt, causing sea
levels to rise while creating water shortages in
regions dependent on runoff for fresh water.
Strong hurricanes, droughts, heat waves,
wildfires, and other natural disasters may become
commonplace in many parts of the world.
13. More than a million species face extinction from
disappearing habitat, changing ecosystems, and
acidifying oceans.
The ocean's circulation system, known as the
ocean conveyor belt, could be permanently
altered, causing a mini-ice age in Western
Europe and other rapid changes.
14.
15. The greenhouse effect is a natural warming process.
Carbon dioxide (CO2) and certain other gases are always
present in the atmosphere.
These gases create a warming effect that has some similarity
to the warming inside a greenhouse, hence the name
“greenhouse effect.”
16. Increasing the amount of greenhouse gases intensifies the
greenhouse effect. Higher concentrations of CO2 and other
greenhouse gases trap more infrared energy in the
atmosphere than occurs naturally.
The additional heat further warms the atmosphere and Earth’s
surface.
17. Sunlight brings energy into the climate system; most of it is
absorbed by the oceans and land.
18. Some of the infrared energy further
THE GREENHOUSE EFFECT :
warms the Earth.
Heat (infrared energy) radiates
AMPLIFIED GREENHOUSE
outward from the warmed surface of EFFECT:
the Earth.
Higher concentrations of CO2 and
Some of the infrared energy is other "greenhouse" gases trap more
absorbed by greenhouse gases in infrared energy in the atmosphere
the atmosphere, which re-emit the than occurs naturally. The additional
energy in all directions. heat further warms the atmosphere
and Earth’s surface.
Some of the infrared energy is
emitted into space.
21. CO2 and Other Greenhouse Gas Variations
Human Activity and Greenhouse Gas
Reducing Other Greenhouse Gases
Ocean Circulation
Volcanic Eruptions
Solar Variations
Orbital Variations
Land Use Changes
22. Factors that can amplify or reduce the effect of the causes of
change are known as "feedbacks." Some of the key feedbacks
are described in the following sections.
These feedbacks consist of interconnected processes in
which a change in one leads to a change in
another, which ultimately leads to further changes in the first.
23. Aerosols
Clouds
Water Vapor
Ice-Reflectivity
