A man smiles as he carries firewood he bought on a street amid ongoing fuel and cooking gas shortages in Yemen's capital Sanaa December 2, 2015. (Photo by Khaled Abdullah/Reuters)

Fog hangs between pine trees in a forest near Neubrueck, eastern Germany, on November 20, 2012. Meteorologists forecast cloudy sky and temperatures around 5 degrees Celsius for the region. (Photo by Patrick Pleul/AFP Photo)

Fishermen collect their catch from a net at Dojran Lake, Macedonia, January 4, 2017. Fish from the lake is a traditional food for locals for orthodox Christmas eve, which falls on January 6. The lake faced sustainability issues during the 1990s due to drought and excessive use of its water but has since recovered after measures were taken to replenish and sustain water levels, according to local media. Dojran Lake is one of the three natural lakes in Macedonia, and also the warmest. It is said it is also the richest lake in fish in Europe. (Photo by Ognen Teofilovski/Reuters)

In this Tuesday, March 10, 2015 photo, rime ice covers rocks on the summit of Mount Washington in New Hampshire. Rime ice occurs when freezing fog hits stationary objects in frigid conditions. (Photo by Robert F. Bukaty/AP Photo)

A long time exposure shows a Igloo at the “Igloo village” (Iglu Dorf) in front of the famous Matterhorn mountain in Zermatt, Switzerland, late 28 January 2016. The hotel-igloo village made of snow and ice at 2'815 meters about sea level with a bar, a restaurant, bedrooms and wellness are celebrating their 20th anniversary. For this occasion the hosts built the largest classic igloo with a diameter of 13 meters and a ceiling hight of 11 meters in front of Matterhorn in Zermatt, and they will attempt the world record for this Igloo. (Photo by Jean-Christophe Bott/EPA)

An alligator is skinned at All American Gator August 16, 2006 in Pembroke Park, Florida. The company processes gators for their skins, meat and trophies and was at full capacity a day after the start of gator hunting season. This year more than 4,000 licenses were sold with each license allowing hunters to kill two gators. The hunt has been expanded by 41 days over previous years, running August 15 to November 1. (Photo by Joe Raedle/Getty Images)

Makoto Chino eats a purple haze carrot as he works harvesting the morning's vegetables and fruit from his family's farm in Rancho Santa Fe, California August 12, 2014. The gravitational pull of Chino Farm is legendary. Since they don't ship, everyone – whether a top chef or a traveling foodie or a local resident – comes to the farm stand, simply called “Vegetable Shop”, on a dusty corner of this affluent San Diego County town, hemmed in by sprawling housing estates. (Photo by Mike Blake/Reuters)

Revellers celebrate the start of the carnival season, a season of controlled raucous fun that reaches a climax during the days before Ash Wednesday and the start of Lent, at 11.11 am in Cologne, Germany, November 11, 2016. (Photo by Wolfgang Rattay/Reuters)