The solar cycle is an approximately 11-year period during which the Sun’s activity waxes and wanes, primarily characterized by variations in the number of sunspots on its surface. During the peak of the cycle, known as the solar maximum, sunspots, solar flares, and coronal mass ejections are most frequent, and the Sun’s magnetic field flips polarity. Conversely, during the solar minimum, sunspot activity diminishes, and the Sun appears calmer. This cycle was first identified in 1843 by Heinrich Schwabe through the systematic observation of sunspots. The solar cycle influences space weather and can have minor effects on Earth’s climate, with some historical correlations, such as the Little Ice Age coinciding with the Maunder Minimum—a period of low sunspot activity. While solar variations can affect climate, current scientific consensus emphasizes that recent global warming is primarily driven by human activities, especially greenhouse gas emissions.
Back to Climate Change Encyclopedia Index Page