Various environmental crises and natural disasters encourage educational curricula in all countries to accommodate epistemic processes intended to improve students' competency in environmental literacy. Awareness, skills, knowledge, and attitudes towards the environment are part of ecoliteracy competencies measurable using tools. This study aimed to assess the environmental literacy of high school students by means of "Q-methodology" as a tool. The assessment did not evaluate scores but rather emphasised the subjectivity of participants to demonstrate students' diverse ecoliteracy perspectives in the context of environmental and disaster issues. This study combined qualitative and quantitative research methods. It selected 51 participants (26 natural science students and 25 social science students) from three senior high schools in D. I. Yogyakarta Province, Indonesia. The Q-sorting process and data analysis used the "FlashQ" ("Flash"-based application) and "KADE Desktop," respectively. The results discovered five factors in each group, with a cumulative percentage of explained variance of 64% in natural science students and 55% in social science students. The following factors have the same label because of the similarity of participants' opinions described in their answers: recognising positive and negative consequences; reflecting; and identifying problems. Using Q-methodology as an assessment tool can demonstrate which issues are of primary concern to students.