He was a member of the Brazilian delegations to the UNFCCC Conferences of Berlin, Montreal, Bali, Copenhagen, Durban, Warsaw, Lima, Paris, Marrakesh, Bonn and Katowice.

He was one of the promoters of the concept of carbon "positive pricing" and of the recognition of the "social and economic value of mitigation actions" enshrined in Paragraph 108 of the Paris Decision.

[6] Alfredo Sirkis has published ten books, including two national best sellers, Os Carbonários,[7] granted in 1981, Brazil's main literary prize – the Prêmio Jabuti – and Roleta Chilena.

Sirkis has worked as a journalist since his years in exile: Libération and Le Monde Diplomatique (1973–79, France), Expresso, Diario Popular, Republica, A Gazeta da Semana, Jornal Novo, Cadernos do Terceiro Mundo (1994–99 – Portugal) and then in Brazil: Veja (1982–83) and Istoé (1993).

As a city legislator he created the Environmental Protection Areas (APA)[12] of Prainha, Bosque da Freguesia and Lagoa de Marapendi.

As Rio's commissioner for the environment he was responsible for the construction of the largest bicycle network in Brazil, developed the community reforestation in 47 hillside favelas (shanty towns); established the GDA (Environmental Protection Group) within the Municipal Guard and negotiated the end of protracted conflicts with developers in Prainha, Bosque da Freguesia and Morro Dois Irmãos obtaining environmental gains leading to the creation of new public owned parks with satisfactory solutions for the affected business interests.

In the early seventies, he took part in urban guerrilla activities against the regime, in the VPR, a Guevarist group led by former army captain Carlos Lamarca.

Back to Brazil after the 1979 amnesty, he worked as a reporter for weekly magazines, Veja and Istoé and became one of the organizers of the environmental groups that mobilized in the 1980s to defend the Amazon rainforest and to address urban ecology issues.

He collaborated closely with late rubber tapper leader Chico Mendes and organized the Salve a Amazonia demonstration two weeks before his murder, in 1988.