Improving the quality of environmental indicators has become a global concern that necessitates the identification of possible channels through which environmental welfare can be enhanced worldwide. Against this backdrop, this current study aims to elucidate the environmental effects of ethnic diversity, controlling for financial development, urbanization, economic growth, and energy consumption in the context of 51 less-developed countries during the period from 1996 to 2016. For measuring the environmental impacts, we use both the ecological footprint and carbon dioxide emission figures of these countries. Overall, the cointegration analysis confirms the existence of long-run relationships among the study variables. Besides, the regression analysis reveals that ethnic diversity deteriorates environmental quality by surging the ecological footprint and carbon dioxide emission levels of the selected nations. Similarly, financial development and energy consumption are found to impose identical adversities on the environment while urbanization is evidenced to ensure environmental welfare. Lastly, for both the environmental indicators considered in this study, the environmental Kuznets curve hypothesis is verified from the findings. Hence, considering these key outcomes, a set of relevant environmental welfare-related policy interventions are recommended in the context of less-developed countries.