Swiss police officers stand beside of mock gates of the NEAT Gotthard Base Tunnel inside the event hall for the upcoming opening ceremony near the town of Erstfeld, Switzerland May 31, 2016. The celebrations of the opening of the Gotthard Base Tunnel will start on June 1, 2016. With a length of 57 km (35 miles) crossing the Alps, the Gotthard Base tunnel is the world's longest train tunnel. (Photo by Arnd Wiegmann/Reuters)

Public Space series, 2015. This series by Morteza Niknahad and Behnam Zakeri tends toward cinema, taking an almost cartoonish view of modern life in Iran. This work was inspired by the social life of dolphins. (Photo by Morteza Niknahad and Behnam Zakeri/The Guardian)

The Royal Castle is seen a veil of heavy winter smog in Budapest, Hungary on January 30, 2017. (Photo by Laszlo Balogh/Reuters)

People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

A visitor stands in front of a portrait taken by artist Bruce Gilden at the “Masters of Photography” exhibition at the Photokina trade fair in Cologne on September 20, 2016. The fair for the photographic and imaging sector, that is running from September 20 to 25, 2016, presents products from image capture, image processing and storage to image output. Photokina also includes a program of events with congresses, workshops, symposiums and photography exhibitions. (Photo by Patrik Stollarz/AFP Photo)

A view of one of the stands during the inauguration of the Integrated Systems Europe (ISE) fair, the largest audiovisual show in the world, in Barcelona city, Catalonia, north-eastern Spain, 31 January 2023. The event runs until 03 February, gathers 68,000 registered attendees and 1,055 exhibiting companies. (Photo by Quique Garcia/EPA)

Dawn at Blyth beach huts in Northumberland, with the prospect of warm weather over the coming weekend on Friday, October 8, 2021. (Photo by Owen Humphreys/PA Images via Getty Images)

This photo taken on October 23, 2022 shows a soap bubble reflecting the Namsan Seoul Tower at Namsan Park in Seoul, South Korea. (Photo by Xinhua News Agency/Rex Features/Shutterstock)