The green knowledge space: Climate change mitigation technologies in developing countries

• Path-dependency of innovation in CCMTs holds at the country level. • Relatedness increases innovation in CCMTs particularly for developing countries. • Innovation is proxied by patent data for 197 countries over the years 2005–2018. • We created a bipartite network that links countries to technological classes depending on patenting activity. • R&D expenditure in CCMTs related to a country's knowledge base is more promising in creating innovation. Regional studies show that regions develop new technologies related to their existing knowledge base. R&D expenditure targeting sectors related to this knowledge base is, therefore, more promising to create innovative output. Using global patent data, we investigate whether path-dependency of innovation in climate-change mitigation and adaptation technologies (CCMTs) holds at the country level and depends on the country's development level. We study 197 countries during 2005–2018 and find that relatedness is a significant determinant of innovation in CCMTs, with stronger effects for developing countries. We construct a two-mode network linking countries to technological classes based on patenting activity to identify each country's existing knowledge and those CCMTs where they are most likely to innovate. This is valuable for decision-making on R&D spending and especially important for developing countries, which face stringent financial and human capital constraints in technology creation and thus require more targeted investments.