As it turns out the sun's effect is more subtle than simply getting cooler or warmer.The sun is a variable star, but it's variation in thermal output doesn't seem to be the dominate effect, (because it's so small percentage wise), on earth's climate. Variations in the magnetic field seem to have more effect. Sunspots are a "proxy" for that field.
The 1645-1715 period is know as the Maunder Minimum. In terms of the earth's climate, the same period was known as the "Little Ice Age". (Actually the little ice age started a little later, and ended quite a bit later, it was still somewhat evident during the American Revolution.)
Not to be too alarmist, but..
Today's image of the sun. The sun is blank--no sunspots.
However we are at one of the normal minimums in the sunspot cycle...but it's getting a little long in the tooth as those things go.
We are also somewhat, just a few thousand years, overdue for a Big Ice Age.
The more recent data (time runs from right to left in this graph) is "fuzzier" because there are more data points for the more recent periods, not because the temperature is varying more.