Completar frases Fill in the Blanks: The Evolution of Atmospheric CompositionVersión en línea Test your knowledge on the changes in Earth's atmosphere over time! por TEO ROSE 1 evolution oxygen human aerobic Event change atmospheric biological chemical Oxidation geological activities photosynthetic gases volcanic composition climate Great The of is a complex process influenced by various , , and factors . Initially , Earth's atmosphere was primarily composed of hydrogen and helium , but over time , activity released such as carbon dioxide , ammonia , and water vapor . The emergence of organisms , particularly cyanobacteria , played a crucial role in transforming the atmosphere by producing as a byproduct . This oxygen accumulation led to the , which significantly altered the composition of the atmosphere and allowed for the development of life forms . Over millions of years , the balance of gases has continued to due to , including the burning of fossil fuels , deforestation , and industrial processes , contributing to change and global warming . Understanding the historical shifts in atmospheric composition is essential for predicting future changes and mitigating their impacts on the environment .