The Sun has a much higher surface temperature than any of the planets or moons. The Sun's spectrum shows that it has a temperature of 5800 Celsius. The high temperature on the Sun's surface causes it to emit a great amount of radiation, mostly at visible wavelengths. The Sun size also contributes to the large amount of radiation.
The Sun provides all the energy that drives our climate. Global warming is a gradual increase in the average temperature of the Earth. Some parts may actually get cooler. Some solar scientists are considering whether some part of global warming may be caused by periodic but small increases in the Sun's energy output. Some speculate that a 0.2% in the solar output could have the same affect as doubling the carbon dioxide in the Earth's atmosphere.(5)
Issues such as whether the Sun might play a role in global warming have been and are still being debated. A few scientists for several decades have believed that weather patterns have been affected by the electrically charged particles that the Sun sprays out as solar winds. After decades of working on that theory, a 1999 study reported evidence that the Sun's magnetic field had strengthened greatly since the 1880s, which brought more attention to the question of whether increased solar activity the main cause of temperature rise. (6) However, many scientists dispute their finding.
Some believe that there is a strong correlation between the variations in solar irradiance and fluctuations in the Earth's temperature. The number of sunspots gets smaller and cooler when the Earth gets cooler. The opposite happens when the number of the sunspots gets larger, the Earth gets hotter. So important is the sun in climate change that half of the 1.5° F temperature increase since 1850 is directly attributable to changes in the sun. According to some NASA scientists, only one-quarter of a degree can be ascribed to other causes, such as greenhouse gases, through which human activities can theoretically exert some influence.(7) As the 21st century began, some experts thought it plausible that the Sun might have driven part of the previous century's warming.(8)