text: The construction of large-scale microalgae cultivation facilities would inevitably result in negative environmental impacts related to land use change, such as the destruction of existing natural habitats. Microalgae can also under certain conditions emit greenhouse gases, like methane or nitrous oxide, or foul-smelling gases, like hydrogen sulfide, although this has not been widely studied to date. If poorly managed, toxins naturally produced by microalgae may leak into the surrounding soil or ground water.