 In and outside Europe, research on the effects of human activities on the climate produced its first results.van Ypersele received a PhD in physics from UCLouvain in 1986 (with highest honours), with his dissertation on his work done at the United States National Center for Atmospheric Research (NCAR) on the effect of global warming on Antarctic sea ice.The choice for the National Center for Atmospheric Research was related to its large available technological means for atmospheric science research.