Aside from crazy conspiracy theorists, real skeptics of this would be people who acknowledge there is some climate change happening but it's not because of us. A lot of people simply believe it's a natural process. I don't know too much about it but I definitely don't believe the government or whoever is faking it.
Let me get this straight. Humanity has been burning lots of fossil fuels for over two centuries now. It took nature millions of years to remove the CO2 from the atmosphere and sequester it in the form of fossil fuels. Now humanity is converting this form back to CO2 by burning it. Yet, if climate change is related to an increase in CO2 levels, it can't be tied to human action? OK whatever. I don't follow the logic. Even if the bulk of the CO2 is released by volcanoes, nature has been slowly sequestering this excess over millions of years. The contribution of humanity now taking this sequestered CO2 and releasing it back into the atmosphere cannot be helping the situation. This is compounded by the fact that the sun is putting out much more energy than it did eons ago. Therefore, we need less CO2 in the atmosphere to keep this planet habitable, not more.
So, for the sake of argument, even assuming humans are causing it... what are the costs of reducing C02 output? People like to pretend "oh we might as well be safe rather than sorry! Why not? We have nothing to lose!"
Actually we have plenty to lose. Direct loss of life and reduction in quality of life for millions. Economic collapse is potentially another outcome. All for the "Well maybe we MIGHT slow down global warming." This is the main sticking point here. Implementing Co2 reduction as planned will have EXTREME COSTS.
In this context it is very appropriate to demand solid evidence, none of which has yet produced any reliable data suggesting humans are responsible. As you noted the sun cycles are also a factor, and in my opinion THE primary factor, not human contribution to C02 output.
Its actually quite the opposite. All of the CO2 reduction solutions would make the world a better place. Lets say climate change didn't exist. The steps taken to solve climate change would still create sustainable, renewable energy systems, provide energy independence, make energy available in places that do not have access to infrastructure like roads for tankers and power plants. (solar panels and wind turbines), no more reliance on fuel prices.
Big advantages in human health as DALYs caused by air pollution would be mostly eliminated. Cities would be more livable which would encourage more walking and hanging out in green spaces (better quality of life from time spent in green spaces).
The increase in green spaces and decrease in deforestation would reduce ecological harm.
Cutting back on livestock production would force people to eat a healthier diet absent of red meat. You would see heart disease risk diminish.
Public transportation and mass transit availability would increase access and economic opportunities bringing people and ideas closer together.
Also the government is "Satan." Every time that I have to go visit the DMV, I am reminded of this. Thank goodness that I can deal with most government business over the mail or internet these days.