People walk passed sculptures by Chinese artist Minjun Yue on a street outside a museum in Beijing, China on July 5, 2018. (Photo by Nicolas Asfouri/AFP Photo)

A couple watches the sunset over a sea of fog covering the Geneva Lake from Chardonne, Switzerland, 28 December 2015. (Photo by Jean-Christophe Bott/EPA)

People walk during a polluted day in Shenyang, Liaoning province, March 31, 2016. (Photo by Reuters/Stringer)

A tower belonging to the Abengoa solar plant at the Solucar solar park is seen in Sanlucar la Mayor, Spain on October 1, 2018. (Photo by Marcelo del Pozo/Reuters)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)

South Korean girl group KARA arrive during the 21st High1 Seoul Music Awards at Olympic gymnasium on January 19, 2012 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

Police officers detain a Femen activist during a demonstration of supporters of former Spanish dictator Francisco Franco, during annual gathering held on the week of the 45th anniversary of the dictator's death, in Madrid, Spain, November 22, 2020. (Photo by Javier Barbancho/Reuters)

Google has built its first self-driving car prototypes and hopes to test hundreds more models this summer. If all goes well, the company is planning a pilot program in California over the next few years.