evidence: Earth’s climate is warming due to human activities that increase the amount of greenhouse gases in the atmosphere - not because of the Sun. The Sun does influence Earth’s climate, and the amount of energy that reaches Earth from the Sun does change over time, but only by a fraction of a percent (0.1% over an 11-year sunspot cycle, to be exact). These very small variations in solar energy output and the current orientation of Earth relative to the Sun do not account for the climate warming trend we have been experiencing since we began burning fossil fuels and increasing the amount of carbon dioxide in the atmosphere. [...] Thus, the Sun is largely responsible for Earth’s climate. Climate changes caused by the Sun take place over much longer spans of time, hundreds of thousands of years, versus the rapid warming we have been experiencing in recent decades. [...] The amount of energy the Sun produces varies over an 11-year cycle. At the peak of the cycle, called the solar maximum, the Sun is extremely active, with many sunspots and solar storms. After the peak, solar activity decreases for about 11 years until it reaches the solar minimum. Even accounting for these small ups and downs in solar activity, there is not enough of an increase in recent solar irradiance that explains current climate warming.