Harn and Miss Earth 2006Hil Hernandez led the International Coastal Clean-up Day event in Manilain September 2007, which aims to bring together people from all nations to gather and clean their shores once a year. The following month, Harn and the United States Ambassador to the Philippines, Kristie Kenney spoke at the launching of a U.S.-supported, 60-second cinema ad on environmental protection, titled “Eco Defenders vs. Global Warming,” geared towards elementary school children on April 3, 2008. The animated cinema ad was the first of four environmental ads featuring “Tips to Reduce Carbon Footprints.” Harn and EcoWaste Coalition launched the campaign, “Iwas PaputTOXIC 2008,” an eco-friendly alternatives campaign to firecrackers in welcoming the New Year on September 2007, in Quezon City, Philippines. She traveled in Palawan on January 25, 2008 and met with Puerto PrincesaMayorEdward Hagedorn to launch an electrically motorized tricycle with powered batteries under the passenger seat, called "trikebayan," which is a tricycle without noise and air pollution. She was one of the guest speakers in the launching of the "International Year of Sanitation" on February 18, 2008, which coincided with the release of the study funded by the World Bank and the Water and Sanitation Extension Program and the United States Agency for International Development. In the Philippine Daily Inquirer Read-Along storytelling program for children, she read the story titled Sa Bakawan, a story about mangroves, the dangers of pollution and improper waste disposal for over a hundred children at the Nayon ng Kabataan in Mandaluyong City on February 6, 2010, along with Miss Philippines Earth 2009Sandra Seifert and Miss Philippines Earth 2001Carlene Aguilar. The three Miss Earth beauties all celebrated their birthdays in February and decided to reach out and spend time with the children as a gesture of thanksgiving.
By winning Miss Philippines-Earth, Harn earned the right to represent the Philippines at Miss Earth 2007, where she was unplaced. She however won the Miss Photogenic award at the international pageant. The pageant was eventually won by Canada's Jessica Trisko.
Modelling career
In 2001, Harn participated and won the Miss STI 2001college system pageant, the largest information technology-based education system in the Philippines. On the same year she also competed and won the Sta. Lucia Generation Eastmodelling search in the Philippines. In 2002, Harn joined the Bodyshots 2002 modelling competition and she won the Miss Photogenic Award and placed as one of the top five finalists. Currently, she is a part-time model with CalCarrie International Modelling Agency.