11 year cycles, to be exact. Sunspot activity also causes world wide radio communications as well. Ham radio operators love it.
It is not as simple as the article states. There is a correlation between sunspots and weather variability. It has been know for 100 years.
And it is not consistent on the period of the sunspot activity. Some say 11 years others say 14 years. The honest answer is it varies somewhat. But it is what it is.
BUT, we do not see global cooling or warming due to sunspots, and the effects are delayed. Within the past 12 months we have begun to see sunspots again, after a 3 year long quiet period with almost no sunspots. During that minimum Texas has had a drought and extreme heat that no living humans have seen before. It will pass.
Other places East of us have had floods and cold temps.
So, it is not Warming or Cooling that is caused by the sunspot levels, but variability. Weather is very local in nature.
There are some excellent articles on this and other climate studies on this site.
These was the best of the sites for climate deniers.
The current cycle is almost non existent... sunspot numbers are terribly low and we are at the peak of this current cycle this fall. Predictions seem to be that the Sun may be forming another Maunder Minimum and they are saying we may not see sunspots at all during the next cycle. This has happened before so none of this is new... it is a death knell for globull warmists. Things are going to cool quickly if this is true.
Oh and a Extra Class Ham here... 40 years... was an swl before that as a kid... I have seen several cycles but this is the weakest in my lifetime... pathetic really.