Lagmay earned his B.Sc. in geology in 1987 and M.Sc. in 1993 from the University of the Philippines Diliman. He earned his PhD in geology from the University of Cambridge in 2001. He also became a visiting scientist at the Geophysics Department of Stanford University and National Autonomous University of Mexico. He is currently a faculty member of the National Institute of Geological Sciences of the University of the Philippines Diliman. Upon returning to the university as a professor, his research interest focused on volcanic behavior and implications for human activities. His expertise on disaster mitigation allowed him to lead DOST's Project NOAH as executive director in 2012; Project NOAH has been described as the country's leading disaster prevention and mitigation program. Lagmay has published detailed analyses of major disasters in the Philippines such as the Guinsaugon landslide; Mayon eruptions; typhoons Ondoy, Sendong, Pablo, and Yolanda; and storm surges. He was part of the Philippine panel on the Philippine claim to Benham Rise in the United Nations Commission on the Law of the Sea. In 2013, Lagmay was awarded the Outstanding Filipino for Geology and Earth Science, and was awarded as "WikiPinoy of the Year" by WikiPilipinas in 2014 for “empowering the public with open information and insight into the significant issues affecting the country today.” Lagmay was awarded the Plinius Medal by the European Geosciences Union on 15 April 2015, in Vienna, Austria, for his "outstanding interdisciplinary natural-hazard research and natural-disaster engagement in the Philippines, particularly with respect to volcanic hazards, earthquakes, typhoons, landslides and floods." He is the first Asian to receive the award. Lagmay was also a radio personality. He co-hosted RED Alert on DZMM with reporters Atom Araullo and Ted Esguerra. The radio program was recognized in the 9th Hildegarde Awards of St. Scholastica College in 2015, the Communication Management Award of Merit for the Multi-Audience Communication category by the Philippine Quill Awards for 2014 and the 2014 Catholic Mass Media Award for best educational radio program. Lagmay has been a consultant to the World Bank and a member of the Philippine-American Academy of Science and Engineering.
