IMHO three variables that affect air temp, sea ice and snow levels are:
1. Soot and small particles (dust,etc) deposited on ice and snow have a large effect on the amount of solar energy reflected from earth back out to space ( soot and dust lower albedo
of ice and snow causing earth surface to absorb energy instead of reflect it and causing snow/ice to melt).
2. Likewise various aerosols (especially clouds and SO2) have various and strong influence on earth albedo and temps.
3. Volcanoes on land and under the oceans emit lots of particles and chemicals.
I have experience with practical statistics and have followed the attempts at collecting climate data for about 40 years. The earth and its climate are huge, with many areas with minimal data collection. The history of natural climate variations is huge and not well understood. There are so many important variables like the 3 I listed that could have larger effects on climate than CO2, but have not yet been understood.
IMHO it's insane to waste trillions on futile efforts to control CO2 when we are so ignorant of many important climate variables. Although the few intelligent and honest researchers that understand statistics should be encouraged to continue research.