[2][3] Before his appointment as Secretary, Solidum served as an Undersecretary for Disaster Risk Reduction-Climate Change Adaptation at DOST and as the Officer-in-Charge of the Philippine Institute of Volcanology and Seismology (PHIVOLCS).

[4] He also studied in the United States at the University of Illinois Chicago, where he obtained a master's degree in geological sciences.

[4] He first received international attention in 1991 when PHIVOLCS director Punongbayan tasked him to work with the United States Geological Service gathering data at the then restive Mount Pinatubo.

The findings of the team led to Punongbayan to raise an evacuation alert in the area prior to a major volcanic eruption saving thousands of lives in Central Luzon.

[7] He was also appointed as Department of Science and Technology (DOST) Undersecretary for Disaster Risk Reduction-Climate Change Adaptation (DRR-CCA).