 The difference between weather and climate is a measure of time. Weather is what conditions of the atmosphere are over a short period of time, and climate is how the atmosphere "behaves" over relatively long periods of time.  Climate is usually over a 30 day period or longer.

 The Sun  Atmospheric Gases (Greenhouse Gases)  Volcanic Eruptions  Surface Albedo (reflectivity) snow cover  Ocean Currents  Changes in earth’s orbit (Milankovitch Cycles)  Meteorite Impacts  Living organisms (plants, animals, microbes)

 _Geo_Solar_Variation.htm _Geo_Solar_Variation.htm  1645 to 1750 called the Maunder Minimum A period of little to no sunspot activity.

 Small changes in any of these energy budget parameters will cause the earth to heat up or cool off.  Example: More ice would increase reflectivity or albedo creating a positive feedback which would lower the global temperature.

 In 1915 Mt. Tombora erupted in Indonesia. This was the largest eruption in 1,300 years.  The dust surrounded the globe which created a constant fog like haze which blocked out sunlight.  1916 was known as the year without a summer. A deep frost occurred over much of the US in June killing off most of the crops.

 The eruption of Mt. Pinatubo in 1991 put enough aerosols into the stratosphere to lower the global temperature by 0.9 degrees Fahrenheit.

 Long term changes in the earth’s orbit (eccentricity) around the sun and axial tilt can change the overall heat balance of our planet.  A decrease in the axial tilt will cause less extreme seasons in the upper latitudes. These resulting cooler summers do not melt all the snow & ice from the previous winter which over time can lead to an ice age.

 There seems to be correlation with the 100,000 year cycle of the eccentricity in our orbit and ice ages.

 The great oxygen event occurred 2.4 billion years ago.  Oxygen released from photosynthetic blue- green algae combined with iron in the sediment to create red & black bands of oxidized iron.  The banding may be caused by seasonal variations in photosynthesis and oxygen production by algae.