The Sunspot Number is a crucial tool used to study the solar dynamo, space weather and climate change. It has now been recalibrated and shows a consistent history of solar activity over the past few centuries. The new record has no significant long-term upward trend in solar activity since 1700, as was previously indicated. This suggests that rising global temperatures since the industrial revolution cannot be attributed to increased solar activity.
The Maunder Minimum, between 1645 and 1715, when sunspots were scarce and the winters harsh, strongly suggests a link between solar activity and climate change. Until now there was a general consensus that solar activity has been trending upwards over the past 300 years (since the end of the Maunder Minimum), peaking in the late 20th century -- called the Modern Grand Maximum by some.I am skeptical about this. First, this is first time I have heard about the "prevously indicated" increase in solar activity. However, I will take that as a given, even though I have been reading everything I can about sunspot activity for over 20 years.
Second, this is hard on the heels of researchers suddenly, and miraculously, finding all the heat that has been missing for last 20 years in the oceans, despite the fact no one measuring the oceans had noticed it before. The Hiatus has been magically wiped out.
Now, long-standing sunspot activity data has been suddenly, and miraculously, been recalibrated to show steady levels of sunpot activity since the end of the Maunder Minimum.
I would like to see confirmation of this by independent researchers.
Since the industrial revolution followed both the uptick in sunspots following the Maunder Minimum and the end of the Little Ice Age, it still is not clear if the warming earth has experienced since then is anthropogenic or due to increased solar activity.
Now, I believe that there has been a modest uptick in global temperature over the last 150 years, but whether that was totally anthropogenic or only partly is unknown.
Third, a long held belief among researchers that the Great Modern Maximum exists has just been overturned. Global warming consensus, anyone?
This is how science advances. By asking questions, being skeptical about received knowledge, and performing one's own research.