An activist takes a selfie during a protest ahead of the 2015 Paris Climate Conference, in Paris, Sunday, November 29, 2015. More than 140 world leaders are gathering around Paris for high-stakes climate talks that start Monday, and activists are holding marches and protests around the world to urge them to reach a strong agreement to slow global warming. (Photo by Christophe Ena/AP Photo)

Undulatus asperatus (or alternately, asperatus) is a cloud formation, proposed in 2009 as a separate cloud classification by the founder of the Cloud Appreciation Society. If successful it will be the first cloud formation added since cirrus intortus in 1951 to the International Cloud Atlas of the World Meteorological Organization. The name translates approximately as “roughened or agitated waves”.

Beyonce performs during the Formation World Tour at Raymond James Stadium on Friday, April 29, 2016, in Tampa, Florida. (Photo by Frank Micelotta/Invision for Parkwood Entertainment/AP Images)

Triston surfs a wave as his father, Todd, watches in Morro Bay. “Hes the most coordinated 3-year-old I've ever seen”, says the 35-year-old captain/paramedic with the Morro Bay Fire Department. (Photo by Joe Johnston/The Tribune of San Luis Obispo)

An opposition supporter wearing a costume lies on the ground in front of riot police during a rally against Venezuelan President Nicolas Maduro's government and to commemorate the 59th anniversary of the end of the dictatorship of Marcos Perez Jimenez in Caracas, Venezuela January 23, 2017. The sign reads “Venezuelans starve. There is no food or medicine. The underworld kills us. Get out Maduro”. (Photo by Marco Bello/Reuters)

Spanish soldiers of the 7th Airborne Light Infantry Brigade “Galicia” fire a howitzer Light Gun L118 during maneuvers with other units in preparation to NATO's Very High Readiness Joint Task Force (VJTF) in Zaragoza, Spain, April 19, 2016. (Photo by Javier Cebollada/EPA)

Penitentes, or nieves penitentes (Spanish for “penitent-shaped snows”), are a snow formation found at high altitudes. They take the form of tall thin blades of hardened snow or ice, closely spaced with the blades oriented towards the general direction of the sun.

Graham Fink has been documenting the demolition sites of Shanghai for five years, trying to capture the state of flux during this period of rapid urbanisation. His Ballads of Shanghai exhibition is at London’s Riflemaker gallery until Sunday. Here: “Big Dreams”. (Photo by Graham Fink/Riflemaker)