An errant plastic bag flutters across N'Gong Road, one of Nairobi's constantly clogged traffic arteries. The bag gets stuck in a roadside gutter, where it joins a pile of garbage already damming the brown trickle. But if the Kenyan government has its way, this frequent urban sight will soon become a thing of the past.

In a bid to control Kenya's garbage problem, one of the world's most stringent environmental laws was passed last February. After a grace period of six months, the use, manufacture and import of plastic bags was outlawed. The ban applies both to carrier bags with handles and to the thin plastic bags without handles, the sort regularly used for fruit and vegetables. Violations are severely punished with fines ranging from 16,000 to 32,000 euros or even a prison sentence of up to four years. The ban officially came into force on August 28, 2017 and the illegal bags are now seldom seen.

Those behind the plastic bag ban praise it as a necessary and popular measure. Mamo Buro Mamo is deputy director of the Kenyan Environmental Agency NEMA. In his office in Nairobi's industrial district, he sits between photos showing him shaking hands with politicians and farmers in their fields. Kenya's population lives largely in the countryside. "We held question-and-answer sessions on local radio stations to sensitise the local shepherd population to the garbage problem, and there were many, many questions,” said Mamo.

Problems included the goats and cows which kept on eating plastic garbage, which often killed them. And, according to NEMA, plastic bags made up about nine percent of Kenya's total waste before the ban came into effect, meaning the consequences were widespread. "People noticed that plastic really affects their livestock, and also the environment. Many wanted something to change, and the ban came just at the right time.”

The tourism sector should also benefit from the new law. Kenya's breathtaking landscapes and its wildlife make the East African state a dream destination. But its perfect postcard motifs, including the west of the country with its rolling green hills, the Rift Valley which is criss-crossed by dormant volcanoes and the white sandy beaches alongside the Indian Ocean, were often tainted by plastic litter.

But not all Kenyans are convinced of the ban. "When I heard about it for the first time, I thought it was a joke," said Hussein Guyo Galgalo, who works in the small coastal town of Kiflti. Every day he is on the beach, where he teaches tourists to sail his small boat. Until recently, it was hard to imagine this area without its scores of plastic bags left behind in the sand and blown inland. Most Kenyans don’t think twice about littering - and there are virtually no public rubbish bins. Until recently, every supermarket checkout was adorned with plastic bags, which hung in thick bundles, and which were extensively used by the teams of professional shopping packers.

And the passing of the law sparked a wave of criticism. Many voiced anger at the severity of the penalties, the implementation by retailers, and the scarcity of alternative tote bags. Probably the biggest critic of the ban is the Kenya Association of Manufacturers (KAM). In a statement it warned that the local manufacturing industry had not been sufficiently consulted: "There are currently more than 176 plastic manufacturing companies in Kenya, employing almost three percent of all Kenyan workforce. These jobs will suffer from the ban,” KAM argued, adding that the six-month grace period before the law was not enough to close the factories and clear out the stocks of plastic bags.

But NEMA deputy director Mamo is short of sympathy for the complaints. “We started the consultations about ten years ago,” he said, explaining that initial measures were imposed to reduce plastic, but these failed to be implemented by retailers and consumers.

“Then we decided on a long-term solution and we gave the producers plenty of warning about the plastic ban.”

He said there were plenty of alternative materials available and producing the alternatives also generates jobs. In the supermarkets and smaller shops reusable bags made of linen, sisal, hemp, nylon and paper are used. Depending on size and material, they can be bought for between ten cents and one euro. As some Kenyans earn less than fifty euros a month, such prices are beyond the means of many, who now have to bring their own bags from home. These days fruits and vegetables are packed in nets, which are often made of plastic. Street stalls now sell their meat and chapatis packed in plastic film and newspaper.

Meanwhile, the retail industry tries to sidestep the law. Many shops continue to secretly release plastic bags from their remnants. "Some kiosks will not give you plastic bags if they don’t know you. But if they do know you and know that you do not cause any problems, they just hand them out as they did before,” said Hussein Galgalo of Kifili beach.

Betterman Simidi Musasia, who founded the Clean Up Kenya organisation, wants to stamp out this problem. Since 2015, he has led a "crusade," as he calls it, against environmental pollution in Kenya. He focuses on social media campaigns, political lobbying and public-sector clean-ups, as well as volunteer-based garbage collection in communities throughout Kenya.

From Musasia's perspective, the ban is well intentioned, but does not go far enough. He argues that nobody in Kenya feels responsible for waste disposal, neither the government nor the population. "I have talked to people in the slums, but also people at the United Nations, government officials and business people. In Kenya, there is a general apathy about garbage disposal. Politicians believe that it is not their problem.”

For example, take Musasia, a notorious garbage dump in Nairobi's suburb of Dandora. Measuring 26 hectares in size, you can smell it from afar, including in the surrounding residential areas where hundreds of thousands of people live. "Two and a half tonnes of garbage land there every day. You can imagine how many hospital visits this contamination causes during the day. So if a government official tells me what a success the plastic bag ban is while the larger issues regarding this garbage dump are still not addressed, it frustrates me a lot.”

In Kenya, recycling is limited to a few companies who buy garbage from “sorters”, people who search through rubbish dumps for usable raw materials. One of these companies is Alternative Energy Systems. It converts plastic into synthetic oil, which can be used as industrial diesel. Company founder Rajesh Kent is also skeptical about the plastic bag ban: "I think there are better ways to deal with the problem, such as the recycling processes implemented in Europe. In my opinion, the best solution for the country would be to be able to develop a functioning rubbish disposal system.”

Despite criticism, three months after the ban was ushered in, there were signs of significant improvement. "In the past, we saw lots of plastic bags floating on the water, which we then collected with our boat," said Hussein Galgalo. “These days, you may see one or two, but they are very old. The beach is actually much cleaner than before.”

Mamo also points to a positive public response to the ban: "People feel really bad about the piles of plastic and most support the ban,” he said.

The next step for the NEMA vice director will be to build recycling facilities and he is planning a deposit system for plastic bottles. Environmental activist Musasia, however, is concerned about how such a system can be manipulated. "If a plastic bottle can be produced for two cents but returned for ten cents, I can imagine that more plastic bottles will be manufactured,” he said, adding that if such false incentives can be erased from the system, it could work. Overall, Musasia believes that economic incentives are a good idea, arguing that, one thing is certain in Kenya: You can rely on people’s business acumen more than their enthusiasm to protect the environment.