Paleolightning is the study of lightning activity throughout Earth's history. Some studies have speculated that lightning activity played a crucial role in the development of not only Earth's early atmosphere, but also early life. Lightning, a non-biological process, has been found to produce biologically useful material through the oxidation and reduction of inorganic matter. Research on the impact of lightning on Earth's atmosphere continues today, especially with regard to feedback mechanisms of lightning-produced nitrate compounds on atmospheric composition and global average temperatures.