Tham khảo bài viết sự tiến hoá của khí quyển trái đất , khoa học tự nhiên, công nghệ môi trường phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Life started to have a major impact on the environment once photosynthetic organisms evolved. These organisms, blue-green algae (picture of stromatolite, which is the rock formed by these algae seen lower left), fed off atmospheric carbon dioxide and converted much of it into marine sediments consisting of the shells of sea creatures. While photosynthetic life reduced the carbon dioxide content of the atmosphere, it also started to produce oxygen. For a long time, the oxygen produced did not build up in the atmosphere, since it was taken up by rocks, as recorded in Banded Iron Formations (BIFs; picture seen lower right) and continental red beds. To this day, the majority of oxygen produced over time is locked up in the ancient "banded rock" and "red bed" formations. It was not until probably only 1 billion years ago that the reservoirs of oxidizable rock became saturated and the free oxygen stayed in the air. Once oxygen had been produced, ultraviolet light split the molecules, producing the ozone UV shield as a by-product. Only at this point did life move out of the oceans and respiration evolved.
