Climate change plays a large part in the energy system. Earth is more complex, more fruitful than the moon. Earth revolution in the solar system, the North and South hemisphere. North hemisphere is more delicate, because the north ice cap is a desert of sea ice. Green energy in North Hemisphere varies in every region. Tropic of Cancer has many large cities that depend heavily on energy, in particular North Atlantic, and Pacific.
There are many energy sources; and each should be used according to each region on earth. Solar power, single source, most sustainable available all year round in the tropical sunny regions, desert regions.
Petrole, natural gas, coal, are energy sources that are limited, because, they require more energy to extract from the ground and ocean. Petrole is the least carbon emission than coal and natural gas.

North Hemisphere, tundra region gets long winter months, and less sun. There are many mountain glaciers that are very fragile during summer heat. and this region needs clean energy for protection, such as Nuclear energy for long winter.

Rajwantee