How does the sun affect Earth's climate?

The sun plays a crucial role in Earth's climate by providing the energy that drives weather patterns and long-term climate changes. The sun's energy, in the form of sunlight, warms Earth's atmosphere and fuels the processes that create wind, rain, and other weather phenomena. But the sun's energy is not constant; it fluctuates over time, and these fluctuations can have significant impacts on Earth's climate.

One way that the sun affects Earth's climate is through changes in its intensity, which can cause periods of warming or cooling. For example, during the Maunder Minimum, a period from the mid-17th to early 18th century when sunspot activity was greatly reduced, global temperatures dropped by as much as 1°C. On longer timescales, changes in the sun's output of energy over millions of years can cause shifts in Earth's climate, such as the gradual cooling that has occurred over the past 50 million years.

The sun's impact on Earth's climate is also influenced by other factors, such as Earth's rotation and tilt, and the composition of the atmosphere. For example, the ozone layer in the upper atmosphere absorbs harmful ultraviolet radiation from the sun, which helps to protect life on Earth. Additionally, greenhouse gases in the lower atmosphere trap heat from the sun and contribute to the warming of Earth's surface.