David Katoatau, a weightlifter from the island nation of Kiribati which is fast disappearing beneath the rising Pacific Ocean, provided one of the highlights of the Olympic Games.

Katoatau didn't win any medals. But he put on a memorable performance nonetheless, leaping into a gyrating dance in a bid to make get his country - and its plight - noticed.

He wasn't the only one to use the event viewed by almost half the world's population as a chance to send a message about climate change.

Billed as a "Green Games for a Blue Planet", the first Olympics since the Paris Agreement put the environment in the spotlight from the get-go, making it a central focus of the opening ceremony.

Visuals showed the impact of rising sea levels if climate change isn't stopped. The Olympic rings were represented in a formation of trees, and every athlete was invited to plant a tree as part of the games' bid to offset its 3.6 million-ton carbon footprint.

But did the games live up to these high ideals?

Green-wash

"If you take the Olympic opening event it was important messaging. The whole world was watching and that is great to frame the issue in this way," Rio sustainability activist Miguel Lago told DW, "but the city did not get more sustainable because of the Olympic Games – not at all."

There were plenty of well-publicized efforts to reduce the games' environmental impact.

Athletes got their protein hit from fish certified as sustainable and meat guaranteed not to have been produced on deforested land. Waste was kept to a minimum and celebrity chefs figure-headed a scheme to turn leftovers into meals for the homeless.

Winners were awarded medals made from sustainably extracted and recycled metals - but missed out on the customary bouquets of flowers, which were deemed unsustainable.

But critics say that Rio won the bid to host the games with grand pledges on environmental sustainability – and failed to deliver.

Broken promises

"The organizers did not live up to their promises. The Rio Olympics could go down as the most green-washed games in the history of the Olympics," Jules Boykoff, author of "Power Games: a Political History of the Olympics", told DW.

The exact data for the games' carbon footprint and how it will be offset aren't in yet. But for now, Boykoff, a professor of politics and government at Pacific University and former athlete, says, "the wider issues are those that are important to the everyday people in the Olympic city."

"With regards to cleaning up the water and the planting of trees, the people of Rio absolutely got short-changed on the environmental front."

The original bid boasted that 24 million trees would be planted. A report published ahead of the games projected that the real number would be just eight million.

Toxic waters

Long before the games opened Rio was widely criticized for falling at the first hurdle when it admitted that the goal of cleaning up the heavily polluted Guanabara Bay would not be met in time for the games.

Olympic sailors and windsurfers were warned to avoid ingesting water or risk respiratory illnesses, diarrhoea and vomiting. But environmental activists in Rio are more worried about the on-going health risk to the local population.

"This was a gigantic missed opportunity," says Lago, who is co-founder of Meu Rio, a network of civil groups working for a more sustainable city.

"There is no political will invest in this - it implies investment in sanitation which is one of the major structural problems of the city of Rio. 50 percent of the population doesn't have basic sanitation."

As a result, raw sewage is simply pumped into the sea.

Sustainable infrastructure?

Commitments to avoid unnecessary construction also seemed to have been swept aside when Rio chose not to update existing golf courses, but construct a new one - on the protected Marapendi nature reserve.

Still, some infrastructure built for the games will have a lasting impact on the city that could help to bring down its carbon emissions.

Ani Dasgupta is director of the World Resources Institute's Ross Center for Sustainable Cities, which has advised the Rio authorities on the construction on a new bus rapid transport network, light rail line and extension of the city's metro.

"These are lasting investments that will actually make a difference to the mobility of the city, which were made because of the Olympics," he told DW.

The city forecasts that the new infrastructure will increase daily commutes by mass transit from 18 percent to 63 percent.

"Even if it only reaches 50 percent, that's a massive shift for a city like Rio," Dasgupta says.

Bad urban planning

Still, the project is not free of controversy. Boykoff says that while the new metro line has made a real difference to workers living in poorer areas in the north of the city, most of the development is focused on routes to the new Olympic facilities, which don't address the city's most pressing transport needs.

"Most transport experts in the area I have spoken to would not have prioritized creating an increased pathway out to the western zone of the city,” says Boykoff. “The only reason that was done way because of the Olympics."

Lago says the Olympic development spurred investment in new, largely wealthy neighborhoods around the Olympic site, rather than focusing on creating a more compact, sustainable city.

"I really hope the Rio Olympics are the last games organized like that."

No medals for Rio – or the IOC

Part of the problem, Lago says, has been that the International Olympic Committee (IOC) insists on standards for the games' facilities that make it difficult to use existing infrastructure and tends to favor expensive bids with more opportunities for investors.

Rio made a lot of mistakes, "but we need to see it's also the IOC that creates the wrong incentives. The Olympic Games always has problems. But I think in Rio we have really showcased these problems.

"That's the best legacy Rio 2016 can give to the world."