Hourly Forecast Detailed. 1  0am:The Santee, SC forecast for Apr 11 is 63 degrees and Clear. There is 74 percentage chance of rain and 4 mph winds from the South-Southeast. 2  3am:The Santee, SC forecast for Apr 11 is 55 degrees and Clear. There is 79 percentage chance of rain and 4 mph winds from the South.
Most Important Organism? Marine plants produce between 70 and 80 percent of the oxygen in the atmosphere.
A Discovery Health answered. The percentage of oxygen is the same at sea level as it is at high altitudes, which is roughly 21 percent. However, because air molecules at high altitudes are more dispersed, each breath delivers less oxygen to the body. A breath at 12,000 feet (3,657.6 m), delivers 40 percent less oxygen to the body than it does at sea level. At 18,000, feet, a breath takes in 50 percent less oxygen.