The atmosphere is always there but rarely do we actually think about it.  It is above us but we do not comprehend how it is keeping us safe and warm throughout our lifespans.  Granted, here in Phoenix some would agree that it keeps us too warm, but the atmosphere is the unsung hero of humans.  In this unit we will talk about the layers of the atmosphere and which parts help us how.  We will also talk about the factors that affect our climate and make our summers so darn evil.