Harini Bambang Wahono's classroom is a kaleidoscope of greens, a fitting colour scheme for the 77-year-old grandmother who has been teaching green ways for almost 30 years.
A poster on the wall commands: "Reduce, recycle, reuse, replant" -- the philosophy that Ibu Bambang, as she is known, seeks to spread throughout her Jakarta neighbourhood.
Doing so presents a particular challenge in polluted Jakarta, a mega-city of at least 11 million, but Ibu Bambang has won wide recognition for her efforts to re-green the Banjarsari community, a neighbourhood of narrow criss-crossing streets just off a traffic-clogged main road.
Homes are shaded by potted plants, bins encourage waste separation and residents recycle their garbage.
Photographs on Ibu Bambang's classroom walls show visitors coming from as far away as Bangladesh to see how one person puts the slogan "think globally, act locally" into daily practice.
Barefoot, with large bifocals perched crookedly on her nose, Ibu Bambang runs through the lessons she teaches the 218 neighbourhood families and her stream of visitors.
Those red plastic bags? They can be transformed into plastic flowers to decorate a coffee table. Your organic kitchen waste? This accelerator will turn it into odorless compost in a few weeks. And that potted plant keeps away mosquitoes.
"After the environment becomes green and clean, we become healthy too," she lectures. "If we throw away our garbage, only hundreds of years later will it become earth again. It is a very long time. We have to do something so that our earth is not full of waste."
Ibu Bambang's father, an agricultural official during Indonesia's Dutch colonial period, taught her the importance of living in harmony with the land.
"I am still consistent in my love for plants and in managing waste," she tells AFP during an interview in the fan-cooled classroom attached to her home.
"This is even more relevant now, with the issue of global warming."
In 1980, she moved to Banjarsari with her husband, who became the neighbourhood head. Ibu Bambang, a former teacher, led government-sponsored programmes aimed at improving community life, including one on environmental sustainability.
"I thought: What if I turn this neighbourhood's environment into one that I have always dreamed of since I was small -- one full of plants, one that's clean. That's where it all started."
Initially it was tough, as some housewives were illiterate or had very little knowledge of plants, or even basic hygiene and cleanliness.
"Therefore I tried a very personal approach -- offering to teach them to read and write, until later they saw me as some sort of mother," she says.
"Only after that, I asked them to help gradually, slowly turn this environment into a green environment."
In 1996, UNESCO enlisted Ibu Bambang in their efforts to introduce integrated waste management at the neighbourhood level.
Jan Steffen, a UNESCO programme specialist, believes the grandmother has held more than 1,000 training sessions since then, received visitors from 31 of 33 Indonesian provinces, as well as about 10 countries in the region.
While similar programmes in Jakarta have launched successfully, they have tended to peter out, Steffen says.
"That's what makes Ibu Bambang unique: she has not only given a lot of energy towards these initiatives, but she has maintained it over a decade," he said. "She is, in her own modest way, an environmental hero."
In 2003, Banjarsari was seen as such a success that the government declared it a tourist destination, with visitors able to buy medicinal plants and compost sold by residents, thus giving the neighbourhood an economic incentive for their environmentally-friendly habits.
Now Ibu Bambang provides guidance to other neighbourhoods -- about 20 so far -- where residents wish to turn green.
Still, not everyone participates. Ibu Bambang estimates just over half the households on Banjasari are fully on board with her programmes. Those opting out are too busy with their work "or too lazy or just do not care," she sighs.
Despite her impeccably green credentials, Ibu Bambang claims not to know too much about climate change -- but she has the fundamentals down pat, saying: "I only know that global warming will destroy our earth and we have to save our earth."
Her voice will be heard through a documentary being shown at a global climate change conference Indonesia is hosting this week.
The key UN conference gathering some 190 countries is taking place in Bali with the aim of setting a strategy for negotiations to beef up action against climate change after 2012.
Indonesia, home to massive peatlands and natural forests, follows the United States and China as the world's third biggest producer of greenhouse gases.
Ibu Bambang realises her efforts at the grassroots of society are a vital component in raising awareness of the threat of global warming.
"I will continue my activities until the end of my life, maybe, rather than do nothing.
"I am being highly sought after by many, but paid by none," she laughs.
"But I am very happy to do that, I am very happy that I can do something for my people, for my country."