In the 39th Parliament Fleming became the NDP's environment critic. He introduced the "Cosmetic Pesticide and Carcinogen Control Act" and sat on the subsequent Special Committee on Cosmetic Pesticides which investigated potential bans or regulations on pesticides used for cosmetic purposes. Fleming also introduced the "Species at Risk Protection Act", after the government delayed a promise to review its species-at-risk legislation, and the "Sustainable Development Indicators and Reporting Act, 2011" which sought to create a Sustainable Development Board to report on provincial sustainability-related indicators. Fleming sat on the Select Standing Committee on Legislative Initiatives which considered the petition seeking the repeal of the Harmonized Sales Tax.