Heherson T. Alvarez was first elected to the Philippine Senate in 1987 and was reelected for another six-year term in 1992.
As senator, he stood out as Mr. Environment. He chaired the Senate Committee on Environment for ten years and became the leading figure of the environmental movements in Congress having launched practically all the laws and initiatives in environmental issues.
In recognition of his environmental achievements both here and abroad, he was awarded the International Public Policy Achievement, the first non-western to be honored by the prestigious Washington-based Climate Institute.
The major pieces of legislation he authored encompassed environmental protection, human rights, modernizing the economy, and democratizing Philippine politics, among others. These include:
• Comprehensive Agrarian Reform Law (CARL) (RA 6657), the centerpiece program of the Aquino administration which provided for an equitable distribution of land for landless farmers.
• National Integrated Protected Areas System (NIPAS) Act (RA 7586) provides for the establishment and management of the NIPAS for the preservation of national parks, virgin forests, bird sanctuaries and wilderness areas.
• Strategic Environmental Plan (SEP) for Palawan (RA 7611) adopted the SEP for the protection and enhancement of the natural resources and the endangered environment of the province, which is known to be the country's last frontier.
• Department of Energy Law (RA 7638), which liberalized the energy sector and was the instrument used by Ramos administration to address the crippling energy problem then. He also introduced specific provisions in this law that would ensure the protection of the environment such as the use of indigenous and environment-friendly alternative sources of energy.
• Philippine Fisheries Code of 1998 (RA 8550), which provided the guidelines for the use of the country's aquatic and marine resources where he made sure that provisions promoting sustainable development practices were put in place.
• Downstream Oil Industry Deregulation Act, allowing the entry of new oil players in the country, effecting competition and lower, stable fuel prices.
• Export Development Act
• Expanded Quedan Corporation
• Revised Charter of the Philippine Crop Insurance Corporation
• Agriculture and Fisheries Modernization Act
• Cooperative Development Authority
• Cooperative Code of the Philippines
• National Commission on Culture and the Arts Law
• Continuing Registration of Voters
• Anti-Pilferage Act
• Indigenous People Rights Law (IPRA)
• Resolution Declaring April 22 of every year as Earth Day in the Philippines
Through his active intercession, the Philippine Senate ratified various international environmental agreements, such as:
• Montreal Protocol on Substances the Deplete the Ozone Layer
• UN Framework Convention on Climate Change
• Ramsar Convention on Wetlands of International Importance
• Bonn Convention on Migratory Species of Wild Animals
• UN Convention on Biological Diversity
• BASEL Convention on the Transboundary Movement of Wastes
• Co-chairperson, "Philippine Delegation Conference of Parties (COP I), Berlin and COP III, Kyoto, 1997
• Lead Convenor, "Ministerial Meeting of the Advisory Committee on Protection of the Seas (ACOPS)", Shangrila Plaza, Makati, 1996
• Convening Chairman, "Asia-Pacific Conference on Climate Change" 17-19 February 1995, Manila, Philippines
• Delegate, "East Asia Regional Air Toxic Conference", 3-5 October 1994, Hongkong
• Head, "Philippine Delegation to the Southeast Asian Seminar on Management of Coastal Cities and Towns", (Localizing Agenda 21) 08-10 August 1994, Pattaya, Thailand
• Head, Philippine Congressional Team, "Interparliamentary Conference on Global Environment", April 29 - May 02, 1990, Washington, D.C.
• Philippine Representative, "44th Session of the United Nations General Assembly", 12-22 October 1989, (Environmental Forum), New York
• Philippine Legislative Representative, "World Environment Legislators' Forum (WELF)", 9-10 October 1989, Tokyo, Japan
• Philippine Senate Committee on Natural Resources Representative, Asian Conference on Forest Policy Revision, 11-15 July 1989, Bangkok, Thailand
• Head, Philippine Delegation, "Conference on Saving the Ozone Layer", 05-07 March 1989, London
• Keynote Speaker, "Global Warming Conference", Tokyo
• Paneslist, "International Conference on the Defense of the Oceans", USA
• Panelist, "GLOBE Parliamentarians Conference and Climate Institute Symposium", Japan