I posted a graph there that complements your source.

The solar activity curve in blue is NOT sunspot number (a complex formula designed to characterize the 11 year solar magnetic cycle). The units of solar activity are watts per square meter, and corresponds to solar energy output. (In my chart below, it is labeled "Solar Activity".)

I don't know for sure, but I don't think sunspot number and solar activity, are closely correlated. Still, just glancing at it, I do see some vague similarity in the curves in the years you mention. All you can really say for sure, is that all the curves seemed to more or less track each other until around 1970, when CO2 and temperature take off in unison, and solar activity/sunspots remain relatively stable.

The satellite data on sea ice started coming in 1979, and I have confidence in its precision. I know solar energy and sunspot data have been quite dependable for well over a century. I'm not as confident that CO2 and temperature data have been measured consistently for that period, but the fact temperature seems to abruptly start in different years on both graphs suggests they are from different sources. Still, the two temp curves appear to be pretty much in synch. I guess they are statistical averages from multiple weather stations.

So how do I interpret all this? The world is getting warmer and CO2 levels are rising. The sun may have some effect, but it is not clear how much, and something drastic happened around 1970 and is superimposed on that, that the ice data confirms. What could cause the sudden change? If I had to guess, I'd say the ocean's abilility to hold excess CO2 in solution is saturating, and that has caused atmospheric levels of the gas to rise, but I could be wrong. Sudden rises in CO2 could also be a result of deforestaion in the Amazon.

There has been a lot in the news lately of dropping pH in the sea, allegedly due to CO2 dissolved in the water.