The largest opportunity to enact favourable change is in the stationary energy or electricity generation sector. It singularly accounts for a major portion of global emissions and pollution around the world. There is an increasing awareness around the globe about this issue and measures are increasingly being implemented (such as emissions trading schemes in Europe and the introduction of new measures in China).
There is significant debate between the pros and cons of Renewable Energy (Wind & Solar) vs Fossil Fuel Energy (Coal & Gas).