She hit the ground running on the very first day in office. She audited all mining sites and firms in the entire republic and stripped environmental certificates from a chunk of the mining industry due to massive violations against the environment and the law, the first time a secretary of environment had done so. This led to a massive public show of support for Lopez's work as DENR secretary and an apology to her for the grilling she suffered on social media. Few of the many notable certificates that were stripped were those for mining companies doing operations in Semirara Island (a key biodiversity area) in Antique, Eastern Samar, Surigao del Sur which is home to indigenous Lumad communities, and Cordillera Administrative Region, which is the melting pot of the northern Luzon indigenous people. Lopez advocated a 100% renewable energy Philippines and was vehemently opposed to mining having stated, "The Philippines does not need mining. " Her anti-mining sentiment was backed by years of Philippine research on mining, both ecologically and economically. She also said that there would be no mining operations of any form on Palawan, which is popularly known as the last ecological frontier of the country. Within less than 2 months, she audited all mining firms from Luzon, Visayas, and Mindanao. She was also an indigenous people (IP) advocate. She immediately established forums for consultations between the DENR and the indigenous people sector in the Philippines, the first time a DENR secretary did so. She also established the first ever DENR public hotline wherein the public could report all environmental violations of any entity in the country directly to the DENR and her office. She was against nuclear energy due to years of research on the matter. The Nuclear Power Plant in Bataan will only contribute to less than 0. 5% to the National Energy Grid when operated and its costs will be much higher, making it unsustainable. She preferred the establishment of more wind and solar power plants, which are massively cheaper and sustainable in the long-run, and the possible cooperation of the Philippines and Australia to establish the first wave energy plants in Asia. The Philippines is the center of the Pacific Typhoon Belt, bestowing it with the most maximized wind and wave shocks in the world.