|Fields||Astronomy, Climatology, Physics|
|Alma mater||University of Pisa,
University of North Texas
|Thesis||An entropic approach to the analysis of time series (2001)|
|Doctoral advisor||Paolo Grigolini|
Nicola Scafetta is a research scientist 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 wide variety 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.
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 is currently a research scientist at the ACRIM Lab group and an assistant adjunct professor in the physics department at Duke University since 2010.
According to Scafetta, total solar irradiance (TSI) measurements gathered by satellites since 1978 are flawed due to the Space Shuttle Challenger disaster preventing the launching of the ACRIM 2 satellite to replace ACRIM 1 and resulting in a two-year data gap in the ACRIM time series. Scientists bridged this gap with data from other satellites and concluded that there was no increased heating from the Sun to contribute to the global surface warming observed between 1980 and 2002. Columbia's Richard Willson, principal investigator of the ACRIM experiments and his colleagues, including Scafetta, challenged these findings and argued for a significant upward trend in average solar luminosity during the same period. Scafetta and West applied a new analysis to the Columbia findings to conclude that, "the sun may have minimally contributed about 10 to 30 percent of the 1980-2002 global surface warming."
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 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, 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 an article published for The Open Atmospheric Science Journal along with Craig Loehle of the National Council for Air and Stream Improvement, 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".
- 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, doi:10.1029/2007JD008437 (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), doi:10.1016/j.jastp.2009.07.007. 
- 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, doi:10.1029/2008GL036307 (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)
- "Nicola Scafetta, PhD" (PDF). Duke University. Retrieved 2012-08-21.
- "ACRIM Staff Information: Science and Instrument Team". ACRIM. Retrieved 2012-08-21.
- Scafetta, Nicola (2001). "An entropic approach to the analysis of time series". University of North Texas. Retrieved 2012-08-21.
- Basgall, Monte (September 30, 2005). "Sun's Direct Role in Global Warming May Be Underestimated, Duke Physicists Report". Duke Today. Retrieved 2012-08-21.
- Dean, Ashley (October 19, 2005). "Hotter sun may affect global warming". The Chronicle. Retrieved 2012-08-21.
- Scafetta, Nicola and Paolo Grigolini (2002). "Scaling detection in time series: diffusion entropy analysis" (PDF). Physical Review E 66 (3). arXiv:cond-mat/0202008. Bibcode:2002PhRvE..66c6130S. doi:10.1103/PhysRevE.66.036130.
- Goforth, Sarah (August 12, 2002). "A new perspective on teen pregnancy: Mathematical approach clarifies subtle patterns, points way to action". Dallas Morning News. Retrieved 2012-08-21.
- Ball, Philip (June 3, 2002). "Less lovin' in summer: Texan teen conception rates linked to school term times". Nature. Retrieved 2012-08-21.
- Scafetta, Nicola (March 18, 2010). "Climate Change and its Causes, a Discussion about some Key Issues" (PDF). Science and Public Policy Institute. Retrieved 2012-08-22.
- Nicola Scafetta, "Empirical evidence for a celestial origin of the climate oscillations and its implications," Journal of Atmospheric and Solar-Terrestrial Physics, 2010 72, 951-970. Full text
- Le Page, Michael (December 18, 2009). "Sceptical climate researcher won't divulge key program". New Scientist. Retrieved 2012-08-22.
- 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
|Wikiquote has quotations related to: Nicola Scafetta|
- Duke web page
- Climate Change and Its Causes: A Discussion about Some Key Issues. Presentation to the EPA, February 2009
- The climate oscillations: analysis, implications and their astronomical origin. Presentation at the JAFoS Symposium, December 2010