>>13413803Climate. The US is split into the wetter Easter half and drier western half, climate change is also making this split much more pronounced and extreme. Past the rockies the US is practically a desert, the warming effect of the sun is more easily felt.
The reason for this split is complicated, having to do with the rockies and the jet stream. However, it's also kind of the same phenomena which is responsible for Spain and the sahara being a desert, while (south) China is a rainy jungle.
