This time, the common denominator between Neptune, Mars, and the Earth is statistically examined. See H. B. Hammel, and G. W. Lockwood, Suggestive correlations between the brightness of Neptune, solar variability, and Earth’s temperature, 34 GEOPHYSICAL RESEARCH LETTERS L08203 (doi:10.1029/2006GL028764) (2007).
The statistical correlation coefficient (the liklihood that one event is influencing another event) between measured solar irradiance and Neptune’s brightness is near 0.90 (or 90%). Amazingly, almost precisely the same statistical correlation is found between the Earth’s measured temperature since 1920 and solar irradiance: .89 (89%).
Another way to think about this is that if you laid the top three trend lines over one another, they are about 90% identical, which—in layman’s terms—is pretty damn close.
And human impact can’t have had any effect on Neptune, so it’s either a huge coincidence that the sun’s radiance is so closely correlated to temperature rises on both planets (highly unlikely since Neptune is thirty times farther away from the Sun than is Earth), or the Sun is driving both phenomena (as the statistics say it is—with 90% certainty).
Thx to Hammel & Lockwood, and NewsBusters