The Olympic opening ceremony may have been light on many of the social issues facing Rio de Janeiro.
But it was heavy on climate change — even if it sent a mixed message.
When it came time to present the Olympic rings, the ceremony displayed them with a series of trees arranged carefully around the stage.
Throughout the ceremony, athletes dropped seeds into a series of mirrored planters that were then arranged to look like the rings.
When the Parade of Nations was finished, trees sprang up from the planters and rained confetti throughout the stadium.
It was a heck of a statement, coming after a lengthy segment on global warming.
But then, there were fireworks. Lots of them.
Fireworks aren't exactly the best tool to promote an environmental message.
They contain metal particles used to make the bright colours you see when they light up the sky, The Guardian reported last year.
In India, fireworks during the Diwali festival have been connected to a jump of 30 to 40 per cent in respiratory problems. They have also pushed pollution beyond the levels you find in some Chinese cities, said the newspaper.
The Olympic rings are displayed during the opening ceremony of the Rio 2016 Olympic Games. (Photo: Francois-Xavier Marit/AFP via Getty Images)
Not all fireworks are created equal, however.
Researchers at the U.S. Army's Picatinny Arsenal facility have developed greener fireworks that have replaced chemicals with nitrates that are less harmful — although they too have negative environmental impacts, BBC News reported in 2012.
Fireworks light up the sky during the opening ceremony of the Rio 2016 Olympic Games. (Photo: Morry Garsh/AFP via Getty Images)
Fireworks have become as much a part of the Olympic Games as the lighting of the cauldron and the torch relay.
So of course they were going to show up in the opening ceremony.
They just don't make for the best optics when you're looking to make a cleaner planet.
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