Modelling and forecasting CO2 emissions in the BRICS (Brazil, Russia, India, China, and South Africa) countries using a novel multi-variable grey model

This study reexamines the relationship between energy consumption, urban population, economic growth and CO2 emissions in the BRICS countries (i.e., Brazil, Russia, India, China, and South Africa) during the period 2004–2010, by using a novel multi-variable grey model. The results indicate that the economic growth has a decreasing effect on the CO2 emissions in Brazil and Russia and has an increasing effect in India, China and South Africa, and the CO2 emissions will increase with the increasing of urban population and energy consumption in all BRICS countries. The CO2 emissions in the BRICS countries are further predicted by rolling multi-variable grey forecasting model considering energy consumption and economic growth. China has the greatest growth rate in CO2 emissions, Brazil and India have the greater ones, while Russian Federation and South Africa have the least ones. The results not only contribute to advancing the existing literature, but also merit particular attention from policy makers in the BRICS countries.