The planetary circulation streams have a big influence on the climate. The main effects are:
- Continuous transport of humidity from the equator to the north and to the south tropics.
- Transport of hot air and humidity from the tropics to the temperate zones.
- Transport of warmer air and humidity from the temperate to the colder zones.
The planetary circulation is responsible for keeping the tropical zones from overheating and the colder zones from becoming less cold, despite their negative energy balance.
You can see these effects on the world weather maps