• Solar activity is a natural climate forcing. When the Sun has fewer sunspots, it’s an indicator that it gives off very slightly less solar energy, that is, less heat.
• About every 11 years the number of sunspots reaches a high and then declines.  Sometimes these ‘solar cycles’ last for longer periods. In the late 1600s, people noticed significantly fewer sunspots over a long period called the Maunder Minimum, which corresponded with slightly lower global temperatures (Fig. 2).
• A second slightly cooler period called the Dalton Minimum also corresponded with the so-called ‘Little Ice Age‘ in Europe (Fig. 2).
• Sunspot activity 1880 – 1970 increased slightly, matching a slight increase in temperature. However, sunspot activity subsequently declined while temperatures continued to rise significantly (Fig. 3). This indicates that any activity associated with the Sun in the past 50 years may have slightly helped offset global warming.
• A supernovae might have helped initiate the Quaternary Period (our current Ice Age) 2.5 million years ago.
• Miyake Events (abrupt carbon-14 spikes in the atmosphere due to solar or cosmic particle events) have no impact on climate. 

Future sunspots?

• The current solar cycle—No. 25—began April 2020 (Fig. 1). See NASA for regular updates.