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.
They estimate that the atmosphere three billion years ago had only 0.03 percent of todayâs oxygen levels. That may not sound like much, but it marked a huge shift in the earthâs chemistry. Sunlight alone couldnât have put that much oxygen in the atmosphere. Only life could.