The sun is not active right now. Few sunspots correlates to a weaker magnetosphere which allows a higher number of cosmic rays into the Earth’s SOI. When there are high number of sunspots, the Earth’s magnetosphere lights up (northern lights) and deflects away the worst of those solar rays.
Cosmic rays still make it through, but the heliosphere, the sun’s magnetosphere, extends way out past the orbits of the gas giants. When the sun isn’t active, that solar sheath is weaker, and more cosmic rays make it to the inner planets.
Couple a weak solar cycle with the solar system’s traversal through higher-cosmic-ray containing open space means we get bombarded and cloud cover increases. This causes cooling.
The nutjobs back in the 70s claiming we’re headed toward another ice age were more scientifically accurate than the global warming psychos we hear from now.
Good summary.