Prof. Dr Puay Yok Tan

Dr Tan Puay Yok is a Dean’s Chair Associate Professor, Programme Director for Master of Landscape Architecture and cluster leader of the Landscape Studies group. His academic training was in horticulture science and plant physiology, and his research, teaching, and professional activities now focus on the science, policies, and practices of urban greening and ecology of the built environment. He combines his background in the sciences, experience in urban governance from the public sector, and interactions with practitioners to apply knowledge for urban greening to improve environmental quality and societal well-being. He leads the Urban Ecology Lab@SDE: 

He is the Co-Editor-in-Chief for Landscape and Urban Planning (Elsevier), Associate Editor for Journal of Urban Ecology (Oxford University Press), Editorial Board Member of npj Urban Sustainability (Nature Partner Journals), and Advisory Board Member of The Gardens Bulletin (Singapore Botanic Gardens). He is active in international collaborations, grant reviews and publishes widely in different forums. He also advises on greening policies, landscape design and planning projects in the region as a means of transferring knowledge from the academia to practice. 

With effect from 31 Dec 2019, he is jointly appointed by the National Parks Board, Singapore, as the Group Director of the Singapore Botanic Gardens ( The Singapore Botanic Gardens is a leading institute in tropical botany and horticulture and has over its 160-year history, played a key role in the social, economic and environmental history of Singapore and the region. It is one of only three botanic gardens in the world that is currently inscribed as a UNESCO World Heritage site. He is concurrently the Chief Science and Technology Officer for the National Parks Board (, the national agency responsible for greenery, ecology and conservation matters in Singapore. 

Elizabeth Maruma Mrema

Elizabeth Maruma Mrema is the Executive Secretary of the Convention on Biological Diversity. She has worked with the UN Environment Programme for over two decades and was the Director of the Law Division at UNEP. Prior to joining the Law Division, she was Deputy Director of the Ecosystems Division, in charge of coordination, operations and programme delivery. Prior to these duties, she also served as Executive Secretary of the UNEP/Secretariat of the Convention on the Conservation of Migratory Species of Wild Animals. Her work at UNEP has focused on development, implementation and enforcement of environmental laws, including multilateral environmental agreements at national, regional and international levels.

Before joining UNEP, Elizabeth worked with Tanzania’s Ministry of Foreign Affairs and International Cooperation and left as a Counsellor/Senior Legal Counsel.

During her time with the Ministry, she was also a lecturer in Public International Law and Conference Diplomacy at Tanzania's Centre for Foreign Relations and Diplomacy. She had also served as a pro bono visiting lecturer at the University of Nairobi Law School and in the past at the International Development Law Organization (IDLO), Rome, Italy.

Dr Bram Edens

As Senior Statistician with the United Nations Statistics Division in New York, Bram is the project manager of theNatural Capital Accounting and Valuation of Ecosystem Services project [Natural Capital Accounting and Valuation of Ecosystem Services Project | System of Environmental Economic Accounting], an EU funded project, jointly implemented with UNEP on mainstreaming ecosystem accounting in Brazil, China, India, Mexico, and South Africa.

He has been heavily involved in the development of the System of Environmental Economic Accounting - Ecosystem Accounting [], with a focus on monetary valuation and carbon accounts.

Prior to his return to the UN, Bram worked in various roles for Statistics Netherlands in the National Accounts Department, and most recently as Head of industry, energy and construction in the Business Statistics Department.

Bram holds a Ph.D. in environmental economics from VU University Amsterdam and has published numerous articles on environmental-economic accounting topics. He is a frequent referee for several scientific journals in the environmental domain, and a contributing author to the IPBES Values Assessment.