Sunspots are dark, cooler regions on the surface of the Sun caused by intense magnetic activity. They are known to affect the amount of insolation - the amount of solar radiation that reaches Earth's surface - in a variety of ways. Firstly, sunspots can absorb some of the solar radiation, reducing the amount of insolation that reaches the Earth's surface. Secondly, they can also contribute to the scattering of solar radiation, resulting in a decrease of insolation. Lastly, they can also act as a shield, blocking some of the solar radiation from reaching the Earth's surface, leading to an overall decrease of insolation. Therefore, sunspots can have a significant effect on the amount of insolation that reaches the Earth's surface.