Atmospheric Structure

What is global warming doing to our atmosphere?

http://www.ace.mmu.ac.uk/eae/english.html

We all know that emitting carbon dioxide and other greenhouse gases into the atmosphere is bad. But, what exactly is going on up there?

Atmospheric Gases

The atmosphere is made up of 78% nitrogen, 21% oxygen, and 1% other gases. Part of what makes up the other gases are the greenhouse gases we hear so much about. Here is a list of some:

• Carbon Dioxide

• Methane

• Nitrous Oxide

• Water Vapor

• CFCs

• Ozone

These gases are called greenhouse gases because they trap heat in our atmosphere during the greenhouse effect. Even though carbon dioxide is the most abundant of these gases, methane actually traps over 21 times more heat.

Sources:                                                                                                                                                www.ace.mmu.ac.uk/eae/english.html
www.envirotools.org/factsheets/contaminants/greenhouse.shtml

Residence Time

Residence time is the average amount of time a gas' molecules exist in air.

• Carbon dioxide and nitrous oxide last more than a century

• Methane only lasts a decade

So, why is this important?

The residence time of a gas determines how much of an impact the gas has on global warming.

Think of it this way: every molecule of carbon dioxide we emit today is going to hang around for a century. Even if we completely stopped carbon dioxide emissions, we will still feel the effect of the gas we've already emitted for the rest of our lives.

http://www.ozones.com/FTP/?subDir=/Landscapes

Source: www.lenntech.com/greenhouse-effect/greenhouse-gases.htm

Keeling's Curve

How do we know that carbon dioxide levels are increasing?

Charles David Keeling studied carbon dioxide levels for Scripps Institution of Oceanography. To obtain his data, he set up instruments to measure carbon dioxide concentrations at two remote locations: Antarctica and Mauna Loa in Hawaii. Keeling's Curve is a graph of his data: