A person walks by an Ocean Rebellion activist taking part in a demonstration outside Department for Environment, Food and Rural Affairs (DEFRA) in London, Britain on September 15, 2021. (Photo by Hannah McKay/Reuters)

Aoife Ni Heochaidh enjoys the sunrise as she welcomes winter solstice at the 5000-year-old stone age passage tomb of Newgrange in the Boyne Valley, as entry inside the chamber is closed for the second year due to coronavirus disease (COVID-19) pandemic, in Newgrange, Ireland, December 21, 2021. (Photo by Clodagh Kilcoyne/Reuters)

Steam comes out of the chimneys of the coal-fired power station Neurath near the Garzweiler open-cast coal mine in Luetzerath, Germany, Monday, October 25, 2021. The climate change conference COP26 will start next Sunday in Glasgow, Scotland. (Photo by Michael Probst/AP Photo)

Indian students play with coloured powders as they celebrate “holi” or the “festival of colours” during a special function in Kolkata on March 12, 2017. Holi, the popular Hindu spring festival of colours, is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 13 this year. (Photo by Dibyangshu Sarkar/AFP Photo)

In this June 29, 2016 file photo, boats docked at Central Marine in Stuart, Fla., are surrounded by blue green algae. The 153-mile-long Indian River Lagoon has been plagued by harmful algae blooms. Water quality testing data analyzed by the AP showed the average phosphorous level – a byproduct of fertilizers and human waste that algae thrive on, rose nearly 75 percent between 2000 and 2016. (Photo by Greg Lovett/The Palm Beach Post via AP Photo)

A motorcyclist ferries a pillion rider sitting on goods in Phnom Penh on June 6, 2017. (Photo by Tang Chhin Sothy/AFP Photo)

Danusorn Sdisaithaworn, 10, poses for a portrait during an annual Poy Sang Long celebration, a traditional rite of passage for boys to be initiated as Buddhist novices, while he visits a relative's house outside Mae Hong Son, Thailand, April 4, 2018. (Photo by Jorge Silva/Reuters)

Fifty years ago, as France exploded in mass protests, words scrawled on the walls of the Sorbonne summed up the revolutionary zeal of the time: “Run free, comrade, we’ve left the old world behind!”. Sexual liberation, artistic creativity and anti-capitalism were the order of the day. For those who were there, it was an unforgettable time. Here: A wounded student is transported by first-aid workers during riots on the Boulevard Saint-Michel, Paris, France on May 6, 1968. (Photo by Gökşin Sipahioğlu/SIPA Press)