Arnold is an agronomist, environmental scientist, and geographer. He has more than 15 years of research experience in the fields of agriculture, natural resource, applied climate science, human ecology, quantitative geography, and geographic information system. In 2021, he was awarded as one of the Outstanding Young Scientists by the National Academy of Science and Technology for his contribution to the advancement of human ecological research in the Philippines. Currently, he is the Editor-In-Chief of the Journal of Human Ecology, and serves on Editorial Board in two (2) journals under Springer Nature: 1) Spatial Information Research; and, 2) SN Social Sciences.