CO2 is essential to greenhouses, due to it being a necessary component of photosynthesis. Growers have even found that up to a certain amount, increased levels of CO2 yield more crops. For the majority of greenhouse crops, it has been observed that net photosynthesis increases as CO2 levels increase from 340–1,000 ppm (parts per million). Currently, commercial greenhouses obtain CO2 though the burning of carbon-based fuels or directly from tanks of pure CO2. There are many costs associated with these processes, such as contaminated fuels, shipping costs, and overarching environmental damage. With its on-site, air capture technology, Global Thermostat supplies greenhouses with CO2, unmitigated by the prohibitive costs posed by current technologies.