Global Warming
What Is It?
Global warming is the gradual increase of the
temperature of the earth, which in turn causes changes in climate.
Earth hasWarmed by about
1 degreeFarenheit over
The past 100 years.
What is Climate?• It is the long-term
average (usually 30 years) of a particular region’s weather pattern.
• At the peak of the last ice age (18,000 years ago), The temperature was only 7 degrees colder than it is today, and glaciers covered much of North America!
So You See…Even a small increase in temperature over a long
time can change the climate.
When the climate changes, there may be big
changes in things that people depend on. These things include the level of the oceans and the places
where we plant crops. They also include the air
we breathe and the water we drink.
What Might Happen to Human Health?
Global warming may cause an increase in heat stress and other heat related health problems.
Ecological disturbances, air pollution, changes in food and water supplies, and coastal flooding may also affect human health.
Poor people, poor countries, very young children, and the elderly will run the highest risks without the money and resources needed to cope.
How will it Effect Our Ecosystems?
• If future climate changes occur as rapidly as predicted, an upset in the delicate balance of rainfall, temperature, and soil type could seriously endanger many plants and animals and their
habitats.
What About our Sea Level?
• Global warming may make the sea level become higher. Warmer weather makes the glaciers melt and adds more water to the ocean.
• Warm temperatures also make water expand. This takes up more space and the level of the sea rises.
• It could rise as much as 3 feet during the next century!
• What problems could this cause?.........
Coastal flooding could cause saltwater to flow into areas where salt is harmful,
threatening plants and animals in those areas.
Flooding and beach erosion could affect oceanfront property and reduce the quality of drinking water.
What about our Crops and Food Supply?
Global warming may make the Earth warmer in cold places, giving people in those places a chance to grow crops in new areas.
BUT… It may also bring droughts to many
parts of the world. This would leave people without enough to eat because they couldn’t grow the food that they need.
What is the Greenhouse Effect?
The greenhouse effect is what causes global
warming.
It is called “greenhouse effect” because it is the same process that keeps
the air inside greenhouses (and parked cars) warmer
than the air outside.
The glass in greenhouse windows is transparent to visible light radiated
from the sun.
This light heats the surface of materials inside the
greenhouse, which emit longer wave-length infrared
radiation.
Infrared radiation cannot penetrate the glass and is
trapped…
Causing the inside air to warm up.
Water vapor, clouds, carbon dioxide, & other gasses in
our atmosphere act like the greenhouse glass by
preventing some of the infrared radiation emitted by
the earth to escape into space.
These are called“greenhouse gasses”.
Where Do Greenhouse Gasses Come From?
Volcanoes
Forest fires, crop burning,and clearing of rain forests
Automobiles and other internal-combustionengines
CFCs used in refrigerators,air conditioners and aerosol spray cans.
Because the levels of these gasses are increasing, more
and more of the heat radiated by the earth’s
surface is trapped in the atmosphere…
…causing our world to heat up.
The Greenhouse Effect
• Solarradiationpassesthroughthe clearatmosphere.
Most radiationis absorbedby the earth’s surface andwarms it.
Some solar radiationis reflected bythe earth and the atmosphere.
Some of the infrared radiationpasses through the atmosphere,and some is absorbed and re-emitted in all directions by Greenhouse gas molecules. The effect of this is to warmthe earth’s surface and the lower atmosphere.
The greenhouse effect is important. Without it, the Earth would not be warm
enough for humans to live.
But, if it becomes Stronger, it could makeThe Earth warmer than
Usual. Even a little Extra warming may cause
Problems for humans, Plants, and animals.
WE CAN
MAKE
A
DIFFERENCE!
Global warming may be a big problem, but there are many
little things we can do to make a difference.
If we try, most of us can do our part to
reduce theamount of greenhouse gasses that we put into
the atmosphere.
Many greenhouse gasses come from
things we do every day.
SAVE ELECTRICITY
Whenever we use electricity, we help put greenhouse gases into
the air. By turning off lights,
the television, and the computer when you are through with them, you
can help a lot.
BUS
WALK
BIKE
You can save energy by sometimes taking the bus, riding a bike, or waking.
It’s fun and a great way to reduce
greenhouse gases.
Trees absorb Carbon dioxide from the air.
Plant Trees
RECYCLE
Cans, bottles, plastic bags, and newspapers.When you recycle, you send less trash to the
landfill and you help save natural resources, like trees, oil, and elements
such as aluminum.
Cars are an important part of life for most people. But they
also cause pollution and release a lot of greenhouse gases into
the air.
Fortunately, there are some cars that are better
for the environment…
These cars can travel longer on a smaller
amount of gasoline. They don’t pollute as much,
either.
Using these kinds of cars can help reduce
the amount of greenhouse gases in
the air.
Solar energy is energy that comes from the
sun.It can be usedto heat homes,buildings, water, and to make electricity.
Today, more than 200,000 houses in the U.S. use this type of energy.