nitrogen fixation. One example of a non-biological process responsible for nitrogen fixation is lightning. Lightning strikes are short-lived, high-intensity electrical discharges that can reach temperatures five times hotter than the surface of the Sun. As a result, as a lightning channel travels through the air, ionization occurs, forming nitrogen-oxide (NOx) compounds within the lightning channel. Global production as a result of lightning is around 1–20 Tg N yr−1. Some studies have implied that lightning activity may be the "greatest contributor to the global nitrogen budget", even larger than the burning of fossil fuels. With anywhere between 1500 and 2000 thunderstorms and millions of lightning strikes occurring daily around the Earth, it is understandable that lightning activity plays a vital role in nitrogen fixation. While nitrogen oxide compounds are produced as a lightning channel travels toward the ground, some of those compounds are transferred to the geosphere via wet or dry deposition. Variations of nitrogen in terrestrial and oceanic environments impact primary production and other biological processes. Changes in primary production can impact not only the carbon cycle, but also the climate system. The lightning-biota climatic feedback The lightning-biota climatic feedback (LBF) is a negative feedback response to global warming on a time scale of hundreds or thousands of years, as a result of increased concentrations of nitrogen compounds from lightning activity deposited into biological ecosystems. A zero-dimension Earth conceptual model, which took into account global temperature, soil available nitrogen, terrestrial vegetation, and global atmospheric carbon dioxide concentration, was used to determine the response of global average temperatures to increased concentrations from lightning strikes. It was hypothesized that as a result of increasing global average temperatures, lightning production would increase because increased evaporation from oceans would promote enhanced convection. As a result of more numerous lightning strikes, nitrogen fixation would deposit more biologically useful forms of nitrogen into various ecosystems, encouraging primary production. Impacts on primary production would affect the carbon cycle, leading to a reduction in atmospheric carbon dioxide. A reduction in atmospheric carbon dioxide would result in a negative feedback, or cooling, of the climate system. Model results indicated that, for the most part, the lightning-biota climatic feedback retarded positive perturbations in atmospheric carbon dioxide and temperature back to an "equilibrium" state. Impacts of the lightning-biota climatic feedback on curbing anthropogenic influences on atmospheric carbon dioxide concentrations were investigated as well. Using current levels of atmospheric carbon dioxide and