Narain began working with the Centre for Science and Environment in 1982, working with the founder Anil Agarwal, while completing her studies at the University of Delhi. In 1985 she co-edited the State of India's Environment report, and then went on to study issues related to forest management. For this project, she traveled across the country to understand people's management of natural resources. In 1989 Narain and Anil Agarwal wrote 'Towards Green Villages' on the subject of local democracy and sustainable development. In her years at the Centre, she has studied the relationship between environment and development and worked to create public consciousness about the need for sustainable development. In 2012, she wrote the 7th State of India's Environment Reports, Excreta Matters, an analysis of urban India's water supply and pollution. Over the years, Narain has also developed the management and financial support systems needed for the Centre, which has over 100 staff members and a dynamic program profile. In the early 1990s, she got involved with global environmental issues and she continues to work on these as researcher and advocate. Her research interests are wide-ranging - from global democracy, with a special focus on climate change, to the need for local democracy, within which she has worked both on forest-related resource management and water-related issues. Narain remains an active participant, both nationally and internationally, in civil society. She is currently in charge of the Centre's management and plays an active role in a number of research projects and public campaigns. Under her leadership, Centre for Science and Environment exposed the high level of pesticides present in American brands of soft drinks such as Coke and Pepsi. Narain serves on the boards of various organizations and on governmental committees and has spoken at many forums across the world on issues of her concern and expertise. In 2008 Narain delivered the K R Narayanan Oration on "Why Environmentalism Needs Equity: Learning from the environmentalism of the poor to build our common future". In 2020, she served on “A future for the world’s children?”, a WHO-UNICEF-Lancet Commission, co-chaired by Helen Clark and Awa Coll-Seck.
Narain appeared alongside Leonardo DiCaprio in the documentary Before The Flood and talked about the impact of climate change on the Monsoon in India and how it affects farmers.
Publications
In 1989 Sunita co-authored the publication Towards Green Villages advocating local participatory democracy as the key to sustainable development.
In 1991 she co-authored the publication Global Warming in an Unequal World: A case of environmental colonialism
In 1992 she co authored Towards a Green World: Should environmental management be built on legal conventions or human rights?
Since the Kyoto Protocol in 1997, she has worked on a number of articles and papers on issues related to flexibility mechanisms and the need for equity and entitlements in climate negotiations.
In 2000, she co-edited the publication Green Politics: Global Environmental Negotiations, which looks at the emerging ecologicalglobalisation framework and puts forward an agenda for the South on global negotiations.
In 1997, pushing the concern for water harvesting, she co-edited the book Dying Wisdom: Rise, Fall and Potential of India's Water Harvesting Systems.
Since then, she has worked on a number of articles on the policy interventions needed for ecoregeneration of India's rural environment and poverty reduction.
In 1999, she co-edited the State of India's Environment, The Citizens' Fifth Report
and in 2001, Making Water Everybody’s Business: the practice and policy of water harvesting.
