Subject
future aspect
energy
5
energy economy
3
world energy consumption
3
energy consumption
2
energy policy
2
energy supply
2
society
2
sustainable development
2
carbon dioxide cycle
1
coal
1
environment
1
environmental policy
1
forecasting
1
green energy
1
natural gas
1
nuclear energy
1
nuclear power
1
petroleum substitution
1
renewable energy source
1
research policy
1
science policy
1
solar energy
1
sustainable use
1
wind
1
wood
1