City skyscrapers stand on the waterfront on Palm Jumeirah artificial island in Dubai, United Arab Emirates.

Gilles Ledos/Bloomberg

City skyscrapers stand on the waterfront on Palm Jumeirah artificial island in Dubai, United Arab Emirates.

Lava fountains are pictured at the site of a fissure eruption near Iceland's Bardarbunga volcano September 2, 2014. A fissure eruption near Iceland's Bardarbunga volcano was still spouting lava on Monday but no ash, a day after an eruption that briefly caused the country to raise its ash alert level for aviation to its highest level. Iceland's largest volcanic system - 190 km long and up to 25 km wide (118 miles by 15.5 miles) - has been hit by thousands of earthquakes over the last two weeks, putting scientists have been on high alert.

Armann Hoskuldsson/Reuters

Lava fountains spew out at the site of a fissure eruption near Icelands Bardarbunga volcano

A wall in Princes Street Gardens in Edinburgh, Scotland, as the Scottish independence referendum campaign continues.  Picture date: Tuesday September 2, 2014.

Danny Lawson/PA

A wall defaced with a pro independence slogan in Princes Street Gardens in Edinburgh, Scotland, as the Scottish independence referendum campaign continues

An armed pro-Russian separatist stands next to an APC in the city of Donetsk, eastern Ukraine, September 2, 2014.

Maxim Shemetov/Reuters

An armed pro-Russian separatist stands next to an APC in the city of Donetsk, eastern Ukraine

Residents launch paper boats during celebrations for the 69th anniversary of the end of World War Two in the far eastern city of Vladivostok, September 2, 2014. The holiday, marking the victory over Japan in World War II, is a Russian national memorial day, established by then President Dmitry Medvedev and approved by the Russian State Duma and the Federation Council on July 23, 2010.

Yuri Maltsev /Reuters

Residents launch paper boats in the far eastern city of Vladivostok in Russia on Tuesday to mark the 69th anniversary of the end of the second world war.

A firefighter adjusts his safety helmet as he tries to extinguish a fire at the park Floresta Nacional in Brasilia, Brazil, 01 September 2014. Six teams, a helicopter and an aircraft were mobilized to contain the fire. The Brazilian capital suffers of current low humidity and a period of drought.

Fernando Bizerra Jr/EPA

A blaze engulfs part of a national forest in Brazil, the Floresta Nacional in Brasilia, as the nation’s capital is hit by a drought.

An Indian boy walks through an old gate decorated with horseshoes in Allahabad, India, Tuesday, Sept. 2, 2014. (AP Photo/ Rajesh Kumar Singh)

Rajesh Kumar Singh/AP

An Indian boy walks through an old gate decorated with horseshoes in Allahabad, IndiaRead more

Pakistani army soldiers stand alert inside the parliament building during an emergency session in Islamabad, Pakistan, Tuesday, Sept. 2, 2014. Lawmakers met over the political crisis roiling the country as thousands of anti-government protesters remained camped out in front of the parliament building, demanding Prime Minister Nawaz Sharif resign.

B.K. Bangash/AP

Pakistani army soldiers stand alert inside the parliament building during an emergency session in Islamabad, Pakistan. Lawmakers met over the political crisis roiling the country as thousands of anti-government protesters remained camped out in front of the parliament building, demanding Prime Minister Nawaz Sharif resign.

To go with Palau-conservation-animal-sha...To go with Palau-conservation-animal-shark-oceans,FEATURE by Neil Sands  In this undated handout photograph received from Richard W. Brooks on August 27, 2014, a grey reef shark (C) is seen riding the incoming tide, to conserve energy, at Blue Corner, off Koror, in the small Pacific island nation of Palau. Palau created the world's first shark sanctuary in 2009 and the move has been so successful that plans are now underway to completely ban commercial fishing in the island nation's vast ocean territory by 2018. AFP PHOTO / Richard W. Brooks  --- EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT " AFP PHOTO / RICHARD W. BROOKS" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVESRichard W. Brooks/AFP/Getty Images

Richard W. Brooks/AFP/Getty

A grey reef shark is seen riding the incoming tide, to conserve energy, at Blue Corner, off Koror, in the small Pacific island nation of Palau. Palau created the world’s first shark sanctuary in 2009 and the move has been so successful that plans are now underway to completely ban commercial fishing in the island nation’s vast ocean territory by 2018. Read more

A fan yawns as he watches the match between Kei Nishikori, of Japan, and Milos Raonic, of Canada, during the fourth round of the 2014 U.S. Open tennis tournament Tuesday, Sept. 2, 2014, in New York. (AP Photo/Darron Cummings)

Darron Cummings/AP

A fan yawns as he watches the match between Kei Nishikori, of Japan, and Milos Raonic, of Canada, during the fourth round of the 2014 U.S. Open tennis tournament on Tuesday. Read more