All living animals need air to breathe, and the most important ingredient in air for our survival is oxygen. Most of the oxygen produced on earth comes from green plants and small plants in the ocean called phytoplankton.
Plants produce oxygen during a process called photosynthesis where plants use carbon dioxide and sunlight to manufacture their food and give off oxygen as a byproduct. The phytoplankton in the oceans produce about 50% of the oxygen we need, and green plants, the other 50%. When it is winter in Frederick County, most of our green plants are inactive, but the phytoplankton are not, and the plants in the southern hemisphere (where it is summer) are manufacturing oxygen. The net result is that our oxygen supply is fairly stable year round.
Nature Note for 1/3/2016