The Role of the Sun in 20th Century Climate Change
"Estimates of Northern hemisphere surface temperatures from 1610 to 1800--during part of the so-called Little Ice Age--correlate well with a reconstruction of changes in solar total radiation--around the time of the Maunder Minimum (Fig. 2c). This suggests, without proving, a predominant solar influence on climate throughout this 200 year, pre-industrial epoch. The reconstructions of solar radiation and surface temperature shown for these years in Figures 3a and 3d tell of an increase in solar radiation of 0.14 percent and a coincident warming of 0.28°C. If we apply the same implied sensitivity to the period since 1850, the 0.13 percent increase in solar radiation in the last 140 years should have produced a warming of 0.26°C, or about half of that observed. If we apply the same relationship to the last 25 years, solar changes can account for less than a third of the warming observed (Fig. 5)."
And what exactly caused the lack of heat from sunlight for the entire period of the Little Ice Age?
Reduced solar activity, indicated by lack of sunspots.
But what you quoted sited an increase in solar radiation and temperature.
The reconstructions of solar radiation and surface temperature shown for these years in Figures 3a and 3d tell of an increase in solar radiation of 0.14 percent and a coincident warming of 0.28°C.
What am I missing here?
Not that it matters as I happen to believe that global warming can be a good thing.
Not to mention we worked so hard to overcome global cooling in the '70s.
That's debatable. See my link in post 124.