Anastasios Tsonis is a Greek-American atmospheric scientist and an emeritus professor at the University of Wisconsin-Milwaukee.
[1] After receiving his PhD, Tsonis became a postdoctoral fellow at the Atmospheric Environmental Service in Canada from 1982–1985.
Tsonis's career began focusing on mathematical models of atmospheric processes, such as vertical wind speeds.
[4] In 2009, Tsonis, with Kyle Swanson, published a paper reporting that natural climate shifts are superimposed on the warming trend observed during the 20th century.
[7] Tsonis has argued that natural factors, especially ocean currents, may contribute more to climate change than human activity, and that the Earth is "now in a period of cooling that could last up to fifty years.