Bell RingerName:2/27/2009

What do you believe global warming is?

Response

Global WarmingThe Greenhouse Effect

• Almost everyone has experienced the temperature difference in an automobile or greenhouse due to window glass.

Global WarmingThe Greenhouse Effect

• This is a true because of a combination of things, some of which we’ve looked at.– All things radiate energy– The radiation wavelength depends upon

temperature

Global WarmingThe Greenhouse Effect

• This is a true because of a combination of things, and some that are new.– High temperature objects radiate short waves – Low temperature objects radiate long waves– Substances are transparent to some

wavelengths

Global WarmingThe Greenhouse Effect

• Let’s consider the short and long waves

• The sun is a high temperature object compared to a fire– High temperature objects radiate short waves– We block Ultraviolet (UV) rays from the sun to prevent

burning.

• Therefore UV rays are short waves.

Global WarmingThe Greenhouse Effect

• Let’s consider the short and long waves

• Fire is a low temperature object compared to the sun– Low temperature objects radiate long waves– We block Infrared rays from a fire and feel cooler

• Therefore Infrared rays are long waves.

Global WarmingThe Greenhouse Effect

• Now let’s consider transparent and opaque, which are opposites

• Glass is transparent and lets visible light through• A piece of metal is opaque and does not let

visible light through, it is reflected

Global WarmingThe Greenhouse Effect

• A substance that is transparent allows waves through.– These waves lose some energy when

traveling through the substance – These waves reflect off surfaces that don’t

absorb them and lose a little more energy

Global WarmingThe Greenhouse Effect

• For radiation from the sun reaching Earth this means– The atmosphere is opaque to some waves

and these are reflected– Some waves are absorbed by the atmosphere– The atmosphere is transparent to some

waves and these are transmitted through the atmosphere

Global WarmingThe Greenhouse Effect

• The atmosphere lets through short waves, just like glass– These waves lose energy and get a little longer– Some of these waves are reflected and eventually

reach the glass or atmosphere again– When they cross the threshold from being transparent

to the glass or atmosphere, they are trapped inside because they reflect

Global WarmingThe Greenhouse Effect

• Before man came along, radiation from the sun balanced the natural terrestrial radiation from Earth’s surface (on average)– We did have extremes called ice ages

• But man is releasing energy from fossil fuels and nuclear energy

• In addition, man is changing the composition of the atmosphere and changing its transparent and opaque abilities– This is global warming

Global WarmingThe Greenhouse Effect

• Greenhouse information

• http://earthguide.ucsd.edu/earthguide/diagrams/greenhouse/

Global WarmingThe Greenhouse Effect

• Cloud Formation

Global WarmingThe Greenhouse Effect

• Cloud Formation

• Have a great weekend!

Global WarmingThe Greenhouse Effect

• Mountain simulation

• http://www.public.iastate.edu/~abc/java/mtnsim/mtnsim.html