Leaders are greedy for more power and land, a large population requires more food, neighbors are becoming to strong
The tilt of the Earths axis can affect where the Suns rays hit the Earth. If the northern hemisphere tilts slightly more than the southern hemisphere, the northern hemisphere is facing the sun more often, this is known as "Summer" for people in the north, and "Winter" for people in the south. Im not sure if that answered your question, but the suns rays bounce off the Earths surface and clouds and sometimes hit each other in our atmosphere.
The answer would be all of the above
Surface winds are in the troposphere, and jet streams are winds that are located in the stratosphere.
