Henrik Svensmark (born 1958) is a physicist and professor in the Division of Solar System Physics at the Danish National Space Institute (DTU Space) in Copenhagen. He is known for his theory on the effects of cosmic rays on cloud formation as an indirect cause of global warming. He detailed his work in the book The Chilling Stars as well as the film The Cloud Mystery.
Henrik Svensmark is director of the Center for Sun-Climate Research at the Danish Space Research Institute (DSRI), a part of the Danish National Space Center. He previously headed the sun-climate group at DSRI. He held postdoctoral positions in physics at three other organizations: University of California, Berkeley, Nordic Institute for Theoretical Physics, and the Niels Bohr Institute.
In 1997, Svensmark and Eigil Friis-Christensen popularised a theory that linked galactic cosmic rays and global climate change mediated primarily by variations in the intensity of the solar wind, which they have termed cosmoclimatology. This theory had earlier been reviewed by Dickinson. One of the small-scale processes related to this link was studied in a laboratory experiment performed at the Danish National Space Center (paper published in the Proceedings of the Royal Society A, February 8, 2007).
Svensmark's research downplays the significance to which atmospheric CO2 has affected recent and historical global warming, with him arguing that greenhouse gases play a considerable role in climate change but solar variations play a larger one.