If you look at a complex, multi-variable, fluctuating system and perform a Fourier Analysis of the data, you can extract amplitude versus frequency content for any cyclic variations.

If you look at a variety of scattered historical data, there is evidence of a widely varying natural climate -- warm periods, cold periods, ice ages, etc... Natural input variables include solar heat flux cycles (main input), volcanic cycles, ocean current cycles, long-term movement of continental plates, etc...

If we had global atmospheric temperature data spanning eons (not just the past 50 years of satellite data), we could perform a Fourier Analysis and extract the amplitude (magnitude) and frequency (inverse of cycle period) data. This would show the relative significance (amplitude) of natural climate variations with low frequency (long cycle times of say 1000+ years), intermediate frequency (cycles over 100-500 years), and high frequency (cycles over a few to 10 years). An above analysis would make it feasible to separate and rank humankind's impact on climate, if significant at all.

One of the many problems with the global warming alarmists is they selectively prefer to use land-based temperature measurements over satellite-based measurements (over half the globe is covered with oceans). The land-based measurements are not all well calibrated (more uncertainty), so they use that "opportunity" to "adjust" the data to fit their expectations.

Since the satellite-based measurements span only up to about 40-50 years, when they do use this data (which doesn't fit their warming models)they also essentially are extracting primarily the high frequency content of Earth's natural climate cycles, ignoring the long time-scale (low frequency) variations. So, at best, they have a partial short-term picture from which they extrapolate and from which they say is entirely due to humans and not other natural causes.

The big question they ignore, regardless of whatever this 50 year snapshot says, is whether Earth is currently experiencing one of its long time-scale warming or cooling trends, regardless of human impacts.

For most complex systems that exhibit cyclic behavior, the amplitude of the lowest frequency content is usually by far the biggest. The high frequency content usually is in the "noise" level of tiny amplitude (relatively speaking). And yet the best temperature data (from satellites) they have to work with is only a brief snapshot in the history of the planet, likely representing "noise" level fluctuations in Earth's natural climate.

I'm not saying humans have zero impact on climate. But until we fully understand solar heat flux cycles (and other natural variables) over a much longer time, we are kidding ourselves if we think we have an adequately complete picture of humankind's relative impact to even begin to entertain ideas of making significant changes using political edicts.

Sunspots are what you have to watch to understand global heating and cooling, and yes, the last decade has been a time of relatively few sunspots.