CO 2 emission 2 CO2 emissions 2 Carbon dioxide 2 Commerce 2 Economic and social effects 2 Economic growths 2 Energy conservation 2 Energy management systems 2 Expansion 2 Gross domestic products 2 Information and Communication Technologies 2 OECD countries 2 Pooled mean group 2 Renewable electricity 2 Renewable energies Technology usages 2 Trade openness 2 gross domestic product 2 information and communication technology pooled mean group 2 renewable energy 2 trade openness 2