I have read in many other places, of electrical charges within our solar system being the cause of many effects. Nicolas Tesla was one such believer in this. Sunspot activity, or lack thereof, due to changes of electric charges within the Sun that directly impact warming and cooling of the planets. Not only bound by gravity, but by electrical influences from the Sun. The human effect on temperature on Earth is negligible to the point of near-zero in comparison to the Suns' effects. As for catastrophic change, the Earth and Sun have been in a dance for billions of years so I wouldn't worry about anything drastic happening within our lifetime. Maybe a little ice age but we'll get by okay.
There may effects from outside of our solar system as well.