Nicola Scafetta
Nicola Scafetta is a research scientist at the University of Napoli Federico II. He was formerly at the ACRIM Lab group and an adjunct assistant professor in the physics department at Duke University. His research interests are in theoretical and applied statistics and nonlinear models of complex processes. He has published peer-reviewed papers in journals covering a scatter of disciplines, including astronomy, biology, climatology, economics, medicine, physics and sociology.

Early life and education
Scafetta was born in Italy. He received a Laurea in physics from the University of Pisa in 1997 and a Ph.D. in physics from the University of North Texas in 2001. His doctoral thesis was titled An entropic approach to the analysis of time series.

Career
Scafetta was a research associate in the electrical and computer engineering department at Duke University from 2002 to 2003 and then a research scientist in the physics department from 2003 to 2009. He has been a visiting lecturer at Elon University and the University of North Carolina. Scafetta was a research associate at the ACRIM Lab group and an adjunct assistant professor in the physics department at Duke University for a few years after 2010. He is currently affiliated with the University of Napoli Federico II in Naples, Italy.

He is a member of the American Physical Society, American Geophysical Union and the American Association of Physics Teachers.

ACRIM
Scafetta argues that the total solar irradiance (TSI) measurements gathered by satellites since 1978 are flawed because the Space Shuttle Challenger disaster prevented the timely launching of the ACRIM 2 satellite, which he worked on, to replace ACRIM 1. This results in a two-year data gap in the ACRIM time series, which scientists bridge with overlapping data from several other satellites. They conclude that  heating from the Sun did not increase between 1980 and 2002 and does not significantly contribute to the global surface warming over that period. Some ACRIM investigators, including principal investigator Richard Willson (Columbia) and Scafetta, disagree and argue for a significant upward trend in average solar luminosity during the same period. The Duke University student newspapers report that Scafetta and West's interpretation of Richard Willson's analysis is that "the sun may have minimally contributed about 10 to 30 percent of the 1980-2002 global surface warming."

Scientific contributions
Scafetta developed "Diffusion Entropy Analysis", a method of statistical analysis which distinguishes between Levy Walk noises and Fractional Brownian motion in complex systems. Scafetta used this method in a 2002 analysis of teen pregnancy.

Views on climate change
Scafetta has argued, "At least 60% of the warming of the Earth observed since 1970 appears to be induced by natural cycles which are present in the solar system." According to Scafetta, the only reasonable explanation is that the climate system is modulated by astronomical oscillations.  Natural cycles known with certainty are the 11 (Schwabe) and 22 (Hale) year solar cycles, the cycles of the planets and luni-solar nodal cycles. Jupiter has an orbital period of 11.9 years while Saturn has an orbital period of 29.4 years. These periods predict three other major cycles which are associated with Jupiter and Saturn: about 10 years, the opposition of two planets; about 20 years, their synodic cycle; and about 60 years, the repetition of the combined orbits of the two planets. The major lunar cycles are about 18.6 and 8.85 years. Scafetta's climate model is based primarily on a numerological comparison of secular periodic changes of global surface temperature and the Sun´s periodic  movement around barycenter of the Solar System caused by the revolving planets Jupiter, Saturn, Uranus and Neptune. Periodic modulation of Moon´s orbital parameters by these planets and subsequent modulation of lunar tides is also discussed. According to Scafetta, who provides no physical explanation of that process, "external forcing of celestial origin simply drives the adjustment of the natural rhythms by letting their own energy flow with the same frequency of the forcing. It just passes to the climatic system the information of how it has to oscillate, not the entire energy to make it oscillate. The effect of a periodic external forcing, even if weak, may become macroscopic and all components of the system gradually synchronize with it".

In 2009, Scafetta faced criticism for failing to disclose the computer code required to reproduce his research. Scafetta responded by saying that the code in question had been submitted to a scientific journal and that if "the journal takes its time to publish it, it is not our fault."

In a 2011 article published in The Open Atmospheric Science Journal ecologist Craig Loehle of the National Council for Air and Stream Improvement (a forest industry institution) and Scafetta forecast that the world climate "may remain approximately steady until 2030-2040, and may at most warm 0.5-1.0°C by 2100 at the estimated 0.66°C/century anthropogenic warming rate".

Selected publications
 Nicola Scafetta, Patti Hamilton and Paolo Grigolini, "The thermodynamics of social process: the teen birth phenomenon," Fractals, 9, 193-208 (2001). 
 Nicola Scafetta, Sergio Picozzi and Bruce J. West, "An out-of-equilibrium model of the distributions of wealth" Quantitative Finance 4, 353-364 (2004)." 
 Nicola Scafetta and Bruce J. West, "Multiresolution diffusion entropy analysis of time series: an application to births to teenagers in Texas" Chaos, Solitons & Fractals 20, 119 (2004). 
 Nicola Scafetta, and Paolo Grigolini, "Scaling detection in time series: diffusion entropy analysis," Phys. Rev. E 66, 036130 (2002)."
 Nicola Scafetta, Richard Moon, and Bruce J. West, "Fractal Response of Physiological Signals to Stress Conditions, Environmental Changes and Neurodegenerative Diseases," Complexity 12, 12-17 (2007). 
 Nicola Scafetta, and Bruce J. West, "Phenomenological reconstructions of the solar signature in the NH surface temperature records since 1600." J. Geophys. Res., 112, D24S03,  (2007). 
 N. Scafetta, "Empirical analysis of the solar contribution to global mean air surface temperature change," Journal of Atmospheric and Solar-Terrestrial Physics  71, 1916–1923 (2009), . 
 Nicola Scafetta and Richard Willson, "ACRIM-gap and Total Solar Irradiance (TSI) trend issue resolved using a surface magnetic flux TSI proxy model", Geophysical Research Letter 36, L05701,  (2009). 
Craig Loehle and Nicola Scafetta, "Climate Change Attribution Using Empirical Decomposition of Climatic Data," The Open Atmospheric Science Journal, 2011 5, 74-86. Full text (Loehle & Scafetta Supplemental Info)