Another Climate change Myth Proven False!, page-6

100% the result of CO2.

You see once CO2 exceeds 400ppm this results in the JetStream to become wavier and have further equatorial incursions.
Conversely between 360 and 400ppm CO2 causes the Jetstream to contract.

This is all well known settled science facts Willial. CO2 can do it all!