From The Sustainability Dictionary: The positioning and segmenting of consumers by ecologically-driven concerns and the development of strategies and solutions that will meet their needs and desires with as little negative impact on the Earth as possible. Products and services which satisfy or appeal to these consumers are often called “green” and their advertising and promotion often make claims of less environmental impact in terms of energy, materials, processes, or toxic substances.
In addition, green marketing includes the representation of a company, product, or service as less harmful to nature. This can lead to greenwashing when this represenation is neither sincere nor accurate.
Other terms for this are Environmental Marketing and Ecological Marketing.