Bell Ringer Name: 2/27/2009 What do you believe global warming is? Response

Global Warming The Greenhouse Effect Almost everyone has experienced the temperature difference in an automobile or greenhouse due to window glass.

Global Warming The 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 Warming The 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 Warming The 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 Warming The 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 Warming The 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 Warming The 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 Warming The 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 Warming The 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 Warming The 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 Warming The Greenhouse Effect Greenhouse information grams/greenhouse/ grams/greenhouse/

Global Warming The Greenhouse Effect Cloud Formation

Global Warming The Greenhouse Effect Cloud Formation

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