A woman wearing a mask reacts at her garden which locates next to chimneys of coal-fired power plant in Shijiazhuang, Hebei province, China, January 28, 2015. Beijing introduced tougher regulations this year to combat pollution, keen to overhaul China's unwanted image of smog-choked cities, fouled waterways and heavy-metal tainted soil. (Photo by Kim Kyung-Hoon/Reuters)

Paul, 9, dumps a bucket of water over his head at a fountain near government buildings during hot weather on July 1, 2015 in Berlin, Germany. Temperatures across northern Europe are rising and in Germany a high of 36 degrees is forecast for the weekend. (Photo by Sean Gallup/Getty Images)

The Villarrica Volcano is seen at night from Pucon town, Chile, July 12, 2015. Villarrica, located near the popular tourist resort of Pucon, is among the most active volcanoes in South America. (Photo by Cristobal Saavedra/Reuters)

Teachers carry children away from Briarwood Elementary school after the tornado destroyed the school in south Oklahoma City. (Photo by Paul Hellstern/The Oklahoman)

“On Friday, after something of a show trial, three young women in a Russian punk band were found guilty and sentenced to two years in prison for an anti-Vladimir Putin protest in a Moscow cathedral earlier this year”. – Daniel Schwartz via CBC News

Photo: A woman wears on her chest the text “free p*ssy riot” as a demonstration by supporters of the jailed feminist punk band p*ssy Riot takes place outside the Russian Embassy on August 17, 2012 in London, England. The three women who staged an anti-Kremlin protest in a church in February, were found guilty today of hooliganism motivated by religious hatred, and could face a three-year jail sentence. Supporters are gathering in several cities around the world today as a mark of solidarity. (Photo by Dan Kitwood)

A vendor drinks water as she waits for customers at a roadside flower market in Ahmedabad, India, February 8, 2017. (Photo by Amit Dave/Reuters)

A man climbs up a wooden pole to get a prize during celebration of Maslenitsa, or Pancake Week, a pagan holiday marking the end of winter, near Rumyantsevo, Moscow region, Russia, February 26, 2017. (Photo by Sergei Karpukhin/Reuters)

A woman stands next to a giant jandal on Tamarama Beach as giant sculptures are installed ahead of the “Sculpture by the Sea” exhibition in Sydney on October 19, 2016. Celebrating it's 20th anniversary, Sculpture by the Sea is the world's largest annual, free-to-the-public, outdoor sculpture exhibition. (Photo by William West/AFP Photo)