The Sun warms our planet - the surface, the atmosphere and bodies of water. It allows this mother and young boy to enjoy warmth and light during an outing at the beach. Photo taken in May in the Outer Banks, NC. Click on image for full size (3 Kb) Windows Original

The Sun emits radiation over a wide spectrum of wavelengths. At high frequencies (short wavelengths), radiation from the Sun is highly variable, and is frequently associated with solar activity such as solar flares or sunspots. Because solar activity is known to vary in cycles, such as the 11-yr sunspot cycle (and longer cycles), some scientists have wondered if changes in our weather and climate might be associated with short or long term solar variations. This has been an active area of research for decades, providing an excellent example of the scientific process.

Some scientists have sought to find a link between variations in Earth’s weather and solar variability. Although some scientists have reported such correlations, many subsequent studies have obtained inconsistent results, at times directly refuting the original studies. Examples include studies of apparent relationship between the number of sunspots and variations in wind patterns, or between cosmic rays and clouds.

Other studies have investigated the influence of solar variation on Earth’s climate, again with mixed success. Although a few scientists argue that solar variations may explain recent warming of the atmosphere, the most complete analysis has shown that the very small change of 0.1% in solar radiation associated with sunspots (and the sunspot cycle) is far too small to account for the majority of the warming observed in the atmosphere over the latter half of the 20th century. Indeed, the only way that climate models can match the observed warming of the atmosphere is with the addition of greenhouse gases. For the most comprehensive information on the impact of solar variation on Earth’s climate, visit the Intergovernmental Panel on Climate Change’s list of Frequently Asked Questions, available at http://www.ipcc.ch/ipccreports/ar4-wg1.htm.

The Sun warms our planet - the surface, the atmosphere and bodies of water. It allows this mother and young boy to enjoy warmth and light during an outing at the beach. Photo taken in May in the Outer Banks, NC. Click on image for full size (3 Kb) Windows Original

The amount of radiation given off by the Sun changes with solar activity like solar flares or sunspots. Solar activity is known to vary in cycles, like the 11-yr sunspot cycle (and longer cycles). Some scientists have wondered if changes in our weather and climate might be linked with short or long term solar cycles. Weather is the current atmospheric conditions, including temperature, rainfall, wind, and humidity for a given area, while climate is the general weather conditions over a longer amount of time. This has been an active area of research for decades. It is an example of the scientific process.

Some scientists tried to find a link between changes in Earth’s weather and solar variability. Although some scientists reported such correlations, later studies have not been able to find the same result, casting in doubt or disproving the original studies. Examples include studies of the relationship between the number of sunspots and changes in wind patterns, or between cosmic rays and clouds.

More researchers have looked at the influence of solar variation on Earth’s climate, again with mixed success. Changes in sunspot cycles do change the amount of solar radiation given off by the Sun, but only by a little bit. These changes aren't enough to account for the majority of the warming observed in the atmosphere over the last half of the 20th century. The only way that climate models can match the observed warming of the atmosphere is with the addition of greenhouse gases. If you would like to learn more about the relationship between solar variation and climate, visit the Intergovernmental Panel on Climate Change’s Frequently Asked Questions section of their recent report.

The Sun warms our planet - the surface, the atmosphere and bodies of water. It allows this mother and young boy to enjoy warmth and light during an outing at the beach. Photo taken in May in the Outer Banks, NC. Click on image for full size (3 Kb) Windows Original

But did you know that it's the energy from the Sun that drives our weather? Our climate is also affected by how much energy the Sun gives off.

The amount of energy the Sun gives off changes with solar activity like solar flares or sunspots. Solar activity varies in a cycles.

Some scientists wondered if changes in our weather and climate might be linked with these changes on the Sun. Scientists have done a lot of research and have used the scientific process to see if there were links there.

After much research and experiments, it seems there is not a link between solar cycles and Earth's weather. For example, the number of sunspots on the Sun doesn't change how the wind blows on Earth.

Studies have shown that changes in light given off by the Sun do affect Earth's climate. But these changes in light given off by the Sun are very small, so they don't account for the large changes we are now seeing in the Earth's climate. For example, most of the warming of the Earth called global warming isn't caused by changes in the Sun's energy output. Computer models of the Earth’s climate show that this warming is caused by greenhouse gases added to the atmosphere because of human activity.