Environmental degradation has constantly increased over the years, and has become one of the main contributors to climate change. For this reason, researchers are increasingly on the lookout for parameters that positively impact environmental quality. Green Technology Products are widely accepted as one of the vital tools to minimize the environmental degradation. This paper introduces a new index which is called the Green Openness Index. The index represents the importance of Green Technology Products in a region by means of a measure of trade in Green Technology Products. This new index revisits the trade-environment nexus in a case study of 31 Economic Co-operation and Development (OECD) countries over the period 2007-2017. The empirical findings provide evidence that Environmental Kuznets Curve hypothesis is valid. As such, the new index also opens up a wide span of opportunities for future research, as the index can be used as explanatory variable in numerous different research questions and fields of research. Additionally, the results clearly demonstrate that Green Openness Index (Green Technology Products in trade) reduces ecological footprint. This provides essential insights to practitioners and policy makers involved in the design of sustainable development policies.