Don't they say that Global climate change is based on
high solar activity?

YES of course...
Here is the link : Sunspots reaching 1,000-year high.
But there were not sunspots PLUS greenhouse gases AND lots of populations living at the edge of carrying capacity of the land.

Quoting the article above :
Over the past 20 years, however, the number of sunspots has remained roughly constant, yet the average temperature of the Earth has continued to increase.

This is put down to a human-produced greenhouse effect caused by the combustion of fossil fuels.

This latest analysis shows that the Sun has had a considerable indirect influence on the global climate in the past, causing the Earth to warm or chill, and that mankind is amplifying the Sun's latest attempt to warm the Earth.

The "dunces" reference remind me of a joke:

- How is your uncle?
- He passed away.
- Aww, sorry, what happened?
- A bad cold.
- Oh! That's fine, colds aren't grievous...

On a more serious note I wish there were some sort of overall "market place of consequences" where we could kinda shortsell the fools ignoring the dangers to make them pay for their idiocy. 

"Over the past 20 years, however, the number of sunspots has remained roughly constant, yet the average temperature of the Earth has continued to increase. "

Over the past 20 minutes, my oven has remained constant at 350 degrees, YET the average temperature of my cake in the oven has continued rise. Hmmm, that's wierd. Not. 

Very convincing, custom made for bozos.
It's the bozos which really count, they made 98% of voters and polled populations.

The Myth of Science-based Predictive Modeling
François M. Hemez1
Engineering Sciences and Applications, ESA-WR
Los Alamos National Laboratory