The size as well as the number of sunspots attains maximum value at every 11 years.
Sunspots and other forms of solar activity are produced by magnetic fields, whose changes also affect the radiation that the sun emits, including its distribution among shorter and longer wavelengths.
The earth has a magnetic field with north and south poles.
The magnetic field of the earth is enclosed in a region surrounding the earth called the magnetosphere.
Due to change in magnetic field of the sun, earth’s magnetic field might get affected which consequently affects the weather because the magnetosphere prevents most of the particles from the sun, carried in solar wind from impacting the earth.
The sensitivity of climate to solar radiation changes, as defined earlier, is not well known.
A conservative estimate is that a 0.1 percent change in solar total radiation will bring about a temperature response of 0.06 to 0.2°C, providing the change persists long enough for the climate system to adjust. This could take ten to 100 years.
Changes in visible and infrared solar radiation alter the surface temperature by simple heating; other parts of the spectrum can also affect climate, through paths that are less direct.
An assortment of recent and historical data, including those from ice-cores, corals, and the instrumental weather record, do reveal climatic variations with periods of about eleven years.
A possible solar connection is also often discounted on the basis that climatic events of ten to twelve years duration are neither globally distributed nor always in phase with the ups and downs of the solar cycle.