Classifying green technologies for sustainable innovation and investment

Green technology plays a fundamental role in achieving the global sustainable development goals. However, the lack of a widely accepted classification system for green technology often hinders the development and adoption of green technology. To promote and support sustainable innovation and investment, China initiated the Green Technology Bank (GTB) in 2016, establishing an online database of green technologies. To provide the standardized criterion for classifying these technologies, this study designed a three-level classification system of green technology (CSGT) through a hybrid method that integrates top-down and bottom-up approaches. The proposed CSGT divides green technologies into five major categories, including environmental quality, resource utilization, energy utilization, life health and ecological safety, with 30 secondary categories and 87 tertiary categories. The CSGT enabled the analysis of 2453 selected examples of green technologies. The results provide valuable information for decision makers and green investors to understand the development of green technologies from the perspective of different sources, sectors, application stages, and spatial distribution. The CSGT developed in this study concerns both immediate green challenges and the ultimate goals of sustainable development by integrating long-term visions and market practices, which can reflect national green strategy and local demands at the same time. The CSGT can be applied to other countries and regions to boost their green technology development and can also be used as a communication tool for multiple stakeholders such as technology investors, users, owners, governments, and the general public.