Residents carry a slaughtered pig with a bamboo pole as they walk home on a street, which was shut to traffic due to ice, in Leishan county, Guizhou province January 31, 2015. Blizzards and icy rain that lasted for several days at the end of January have disrupted traffic, collapsed houses and decimated crops in central Chinese provinces, Xinhua News Agency reported. (Photo by Reuters/Stringer)

“Cassowaries are large, flightless birds related to emus and (more distantly) to ostriches, rheas, and kiwis”, writes Olivia Judson in the September issue of National Geographic magazine. How large? People-size: Adult males stand well over five foot five and top 110 pounds. Females are even taller, and can weigh more than 160 pounds. Dangerous when roused, they’re shy and peaceable when left alone. But even birds this big and tough are prey to habitat loss. The dense New Guinea and Australia rain forests where they live have dwindled. Today cassowaries might number 1,500 to 2,000. And because they help shape those same forests – by moving seeds from one place to another – “if they vanish”, Judson writes, “the structure of the forest would gradually change” too. (Photo by Christian Ziegler/National Geographic)

Rooftops of solar powered houses are pictured in Ota, 80 km northwest of Tokyo in this October 28, 2008 file photo. One by one, Japan is turning off the lights at the giant oil-fired power plants that propelled it to the ranks of the world's top industrialised nations. With nuclear power in the doldrums after the Fukushima disaster, it's solar energy that is becoming the alternative. Solar power is set to become profitable in Japan as early as this quarter, according to the Japan Renewable Energy Foundation (JREF), freeing it from the need for government subsidies and making it the last of the G7 economies where the technology has become economically viable. (Photo by Yuriko Nakao/Reuters)

A rider holds on as a bull tries to throw him during the Bull Ride Spectacular on the first day of the 2014 Deni Ute Muster at the Play on the Plains Festival grounds on October 3, 2014 in Deniliquin, Australia. (Photo by Mark Kolbe/Getty Images)

A lunar eclipse appears behind a gargoyle atop the old red Dallas County Courthouse early Wednesday morning, October 8, 2014. The moon appears orange or red, the result of sunlight scattering off Earth's atmosphere. This is known as the blood moon. (Photo by Tom Fox/AP Photo/The Dallas Morning News)

People take part in the Classic Ride Rally in downtown Valencia, eastern Spain, 23 November 2014. Some hundred people on classic bikes from the 20's to the 70's participated in the rally. (Photo by Kai Foersterling/EPA)

A young girl sells balloons by the Yamuna River as devotees carrying idols of the Hindu god Ganesh, the deity of prosperity, immerse the idol on the last day of the ten-day-long Ganesh Chaturthi festival in Delhi, India, September 15, 2016. (Photo by Cathal McNaughton/Reuters)

The villas of Marabe Al Dhafra in Abu Dhabi, United Arab Emirates are home to approximately 2,000 people. Located in one of the hottest regions of the world, the record high temperature here is 49.2C° (120.6F°). (Photo by Benjamin Grant/Penguin Random House)