Yashpal Rathore / Composite image of Fireflies synchronize display just after first shower of monsoon, on moonless night. India.

Juergen Freund / Bleached Staghorn corals (Acropora cervicornis), Great Barrier Reef, Australia, 2017.

Ashley Cooper / Sunflower next to the PS20 solar thermal tower, the only such working solar tower currently in the world. Sanlucar La Mayor, Andalucia, Spain. May 2011

Ashley Cooper / Heliostats, large reflective mirrors directing sunlight to the PS20 solar thermal tower, the only such working solar tower currently in the world. Sanlucar La Mayor, Andalucia, Spain. June 2011

Ashley Cooper / Sun rays reflected onto solar tower at Ivanpah Solar Thermal Power Plant, the largest solar thermal plant in the world. It covers 4,000 acres of desert and produce 392 megawatts (MW) of electricity....

Ashley Cooper / Wind turbine with stacks of coal fired power station in Amsterdam, Netherlands. May 2013

Benjamin Olson / Gentoo Penguin (Pygoscelis papua) wet from rain due to climate change, Antarctica

Paul Williams / Budgerigars (Melopsittacus undulatus) flocking to find water, Northern Territory, Australia

Denis-Huot / Masai giraffes (Giraffa camelopardalis tippelskirchi) in dry season, Masai-Mara Game Reserve, Kenya. March.

Denis-Huot / Cheetah (Acinonyx jubatus) female with cubs sitting in long grass during the dry season, Masai-Mara Game Reserve, Kenya. March.

Denis-Huot / Cheetah (Acinonyx jubatus) resting with rainbow behind it, Masai-Mara Game Reserve, Kenya. September.

Denis-Huot / Two cheetahs (Acinonyx jubatus) in dry season, Masai-Mara Game Reserve, Kenya. February.