Planes land in fog at Heathrow Airport, west London on January 4, 2014, as heavy fog covers a many parts of the south east. (Photo by Steve Parsons/PA Images via Getty Images)

Seven-year-old Dihan Awallidan from Garut, West Java, is not like other boys his age. While most children crave chocolate and candy, Dihan is addicted to cigarettes. The second-grader picked up the habit at the age of 3 and now smokes up to three packs a day, using the pocket money he gets from his enabling parents to feed his addiction. (Photo by Rezza Estily/JG Photo)

The Mount Bromo volcano erupts in the Bryce Canyon, Utah. (Photo by Reynold Dewantara/2016 National Geographic Travel Photographer of the Year Contest)

Russian Foreign Ministry spokeswoman Maria Zakharova dances during the reception in honour of heads of the delegations at the Russia-ASEAN summit in Sochi, Russia, May 19, 2016. (Photo by Host photo agency via Reuters)

A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)

“Catch of the Decade”. Can you guess what happened next? Photo location: Katmai National Park, Alaska, USA. (Photo and caption by Aaron Baggenstos/National Geographic Photo Contest)

A Brussels Airlines aircraft prepares for landing in Cointrin airport during sunrise over the Mont Blanc in Geneva December 1, 2011. (Photo by Denis Balibouse/Reuters)