Given that the European Union -28 countries proposed a target of 3% of the Gross Domestic Product on research and development (R&D) expenditure by 2020, the current study attempts to examine the role of R&D on environmental sustainability. In addition, the study further investigates the long-run and causal interaction between, renewable energy consumption, nonrenewable energy consumption, and economic growth in a n ecological footprint -income function. Notably, the study incorporates research and development (R&D) expenditure to the model as an additional variable, and measures impact of each variable on ecological footprint. Empirical evidence is based on a balanced panel data between annual periods of 199 7 –۲۰۱۴ for selected EU -16 countries. The Pedroni, Johansen Multivariate and Kao tests all reveal a cointegration between ecological footprint, economic growth, research and development expenditure, renewable, and nonrenewable energy consumption. The Fully Modified and Dynamic Ordinary Least Squares model s (FMOLS and DOLS) both suggest a negative significant relationship between the countries’ research and development expenditure and ecological footprint in the long -run. This implies that spending on R&D significantly impacts on environmental sustainability of the panel countries. Our study affirms that nonrenewable energy consumption and economic growth increase carbon emission flaring while renewable energy consumption declines ecological footprint. The panel causality analysis reveals a feedback mechanism between ecological footprint, R&D expenditure, renewable, and nonrenewable energy consumption. We further observed a one – way causality between ecological footprint and economic growth. The current further validates that the Environmental Kuznet Curve Hypothesis (EKC) holds for this panel of EU countries examined. Effective policy implications could be drawn toward modern and environmentally friendly energy sources, especially in attaining the Sustainable Development Goals via spending on R&D .

Introduction

Consumption of energy has become increasingly beneficial in the advancement of many economies in the 21st century. Global dependence on the energy sector as a driver in the development processes has led to an increased level of the world’s demand for energy (Ozcan and Ozturk, 2019) . Among other factors, rise in energy consumption is connected to significant rise in population (Feng et al., 2018) as well as increasing drive for growth and urbanisation among nations particularly the emerging economies. This has further led to the depletion of the environment, thereby threatening the ecological balance of the biosphere (Chu et al., 2017; Alola, 2019a, b; Bekun, Emir & Sarkodie; Saint Akadiri et al., 2019 ) . Additionally, in a bid to achieve industrial expansion and growth, many economies are forced to meet up their increasing energy demands through non -renewable energy (NRE) sources to mitigate adverse environmental consequences . According to Nathaniel & Nathaniel (2019) , industrial growth do not only increases energy use but equally increases the level of environmental degradation through emissions of toxic gases chiefly from nonrenewable energy. The reason is partly due to the little share of eco -friendly renewable energy sources in the global energy market in relation to NRE sources (Ozcan and Ozturk, 2019). Consequently, negative externalities have been generated in the form of carbon emissions, resource depletion, pollution, wildlife endangerment, climate changes and global warming (Hanif et al., 2019).