Cosmic rays don't do any heating, a dose of 1 Gray (100 rads) is only 1 Joule / kg, so if they directly drove climate change, we'd be dead from
acute radiation poisoning every time a cosmic flare occurred.
Workers and firefighters who suffered
acute radiation poisoning died there, and as you walk past their belongings, still in situ 29 years later, your Geiger counter crackles wildly.