INDIA-EARTH-DAY(01 of21)
Open Image ModalYoung Indian girls pose with their painted faces during a 'Save Earth' awareness programme on the eve of World Earth Day at a school in Patiala on April 21, 2015. AFP PHOTO (Photo credit should read STR/AFP/Getty Images) (credit:STR via Getty Images)
Global Citizen 2015 Earth Day Courtesy of Partner Citi(02 of21)
Open Image ModalWASHINGTON, DC - APRIL 18: A general view of atmosphere at the Global Citizen 2015 Earth Day Courtesy of Partner Citi at National Mall on April 18, 2015 in Washington, DC. (Photo by Paul Morigi/Getty Images For CITI) (credit:Paul Morigi via Getty Images)
Global Citizen 2015 Earth Day Courtesy of Partner Citi(03 of21)
Open Image ModalWASHINGTON, DC - APRIL 18: A general view of atmosphere at the Global Citizen 2015 Earth Day Courtesy of Partner Citi at National Mall on April 18, 2015 in Washington, DC. (Photo by Paul Morigi/Getty Images For CITI) (credit:Paul Morigi via Getty Images)
CHINA-LIFESTYLE-ENVIRONMENT-RIGHTS-PETA(04 of21)
Open Image ModalUS model Kelly Chin poses with a body painting to advertise a new pro-vegan Earth Day by PETA (People for the Ethical Treatment of Animals) Asia in Beijing on April 20, 2015. In the advertisement, Kelly's body is painted with the Earth's oceans and continents to draw attention to the fact that animal agriculture is one of the leading causes of climate change and a major contributor to resource depletion, pollution, and world hunger. AFP PHOTO / FRED DUFOUR (Photo credit should read FRED DUFOUR/AFP/Getty Images) (credit:FRED DUFOUR via Getty Images)
PHILIPPINES-ENVIRONMENT-EARTH DAY(05 of21)
Open Image ModalA woman holds a placard as she joins members of an eco-waste coalition and other environmentalist in a march to the presidential Malacanang Palace in Manila on April 21, 2015 a day before Earth Day on April 22. The rally was held to call on Philippine President Benigno Aquino to defend the Clean Air Act law from legislative attacks and keep a local incineration ban intact. AFP PHOTO / Jay DIRECTO (Photo credit should read JAY DIRECTO/AFP/Getty Images) (credit:JAY DIRECTO via Getty Images)
COLOMBIA-ENVIRONMENT-CONSERVATION-EARTH DAY(06 of21)
Open Image ModalBiologist Carlos Galvis measures a Golden Frog (Phyllobates terribilis), the most venomous in the world, in a laboratory at the zoo in Cali, Colombia, on April 21, 2015. The zoo of Cali, has the largest amphibians laboratory in the country, where they perform studies on the conservation of some amphibian species in danger of extinction. Colombia has the second largest biodiversity in the world. Activists across the globe will celebrate Earth Day on April 22 with events aimed at bringing awareness of environmental concerns. AFP PHOTO/LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) (credit:LUIS ROBAYO via Getty Images)
COLOMBIA-ENVIRONMENT-CONSERVATION-EARTH DAY(07 of21)
Open Image ModalBiologist Carlos Galvis holds a Golden Frog (Phyllobates terribilis), the most venomous in the world, is photographed in a laboratory at the zoo in Cali, Colombia, on April 21, 2015. The zoo of Cali, has the largest amphibians laboratory in the country, where they perform studies on the conservation of some amphibian species in danger of extinction. Colombia has the second largest biodiversity in the world. Activists across the globe will celebrate Earth Day on April 22 with events aimed at bringing awareness of environmental concerns. AFP PHOTO/LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) (credit:LUIS ROBAYO via Getty Images)
COLOMBIA-ENVIRONMENT-CONSERVATION-EARTH DAY(08 of21)
Open Image ModalA Poison dark frog (Oophaga lehmanni), is photographed in a laboratory at the zoo in Cali, Colombia, on April 21, 2015. The zoo of Cali, has the largest amphibians laboratory in the country, where they perform studies on the conservation of some amphibian species in danger of extinction. Colombia has the second largest biodiversity in the world. Activists across the globe will celebrate Earth Day on April 22 with events aimed at bringing awareness of environmental concerns. AFP PHOTO/LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) (credit:LUIS ROBAYO via Getty Images)
COLOMBIA-ENVIRONMENT-CONSERVATION-EARTH DAY(09 of21)
Open Image ModalA Cocoi frog (Oophaga histrionica), is photographed in a laboratory at the zoo in Cali, Colombia, on April 21, 2015. The zoo of Cali, has the largest amphibians laboratory in the country, where they perform studies on the conservation of some amphibian species in danger of extinction. Colombia has the second largest biodiversity in the world. Activists across the globe will celebrate Earth Day on April 22 with events aimed at bringing awareness of environmental concerns. AFP PHOTO/LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) (credit:LUIS ROBAYO via Getty Images)
2015 Earth Day Concert(10 of21)
Open Image ModalCommon performs at the Global Citizen 2015 Earth Day on the National Mall, Saturday, April 18, 2015, in Washington. (Photo by Nick Wass/Invision/AP) (credit:Nick Wass/Invision/AP)
2015 Earth Day Concert(11 of21)
Open Image ModalCommon performs at the Global Citizen 2015 Earth Day on the National Mall, Saturday, April 18, 2015, in Washington. (Photo by Nick Wass/Invision/AP) (credit:Nick Wass/Invision/AP)
2015 Earth Day Concert(12 of21)
Open Image ModalGwen Stefani, of the band No Doubt, performs at the Global Citizen 2015 Earth Day on the National Mall, Saturday, April 18, 2015, in Washington. (Photo by Nick Wass/Invision/AP) (credit:Nick Wass/Invision/AP)
MorningStar Farms Earth Day Event(13 of21)
Open Image ModalIMAGE DISTRIBUTED FOR MORNINGSTAR FARMS - Padma Lakshmi invites New Yorkers to take Veg of Allegiance - a pledge to eat less meat - at a MorningStar Farms Earth Day event in New York City on Sunday, April 19, 2015. (John Minchillo/AP Images for MorningStar Farms) (credit:AP Images for MorningStar Farms)
Malaysia Anti Nuclear(14 of21)
Open Image ModalA protestor holds up an anti-nuclear placard during a protest in Bangi outside Kuala Lumpur, Malaysia on Tuesday, April 21, 2015. In conjunction with the World Earth Day on April 22, about a dozen protestors from the Malaysia Socialist Party gathered outside the Malaysia Nuclear Agency to protest the development plans of nuclear reactor in Malaysia. (AP Photo/Joshua Paul) (credit:ASSOCIATED PRESS)
Malaysia Anti Nuclear(15 of21)
Open Image ModalProtestors hold up anti-nuclear placards during a protest in Bangi outside Kuala Lumpur, Malaysia on Tuesday, April 21, 2015. In conjunction with the World Earth Day on April 22, about a dozen protestors from the Malaysia Socialist Party gathered outside the Malaysia Nuclear Agency to protest the development plans of nuclear reactor in Malaysia. (AP Photo/Joshua Paul) (credit:ASSOCIATED PRESS)
Malaysia Anti Nuclear(16 of21)
Open Image ModalProtestors hold up anti-nuclear banner and placards during a protest in Bangi outside Kuala Lumpur, Malaysia on Tuesday, April 21, 2015. In conjunction with the World Earth Day on April 22, about a dozen protestors from the Malaysia Socialist Party gathered outside the Malaysia Nuclear Agency to protest the development plans of nuclear reactor in Malaysia. The words in red read " Nuclear Free Malaysia, Death Awaits and Nuclear Has To Stop. " (AP Photo/Joshua Paul) (credit:ASSOCIATED PRESS)
India PETA(17 of21)
Open Image ModalA supporter of People for the Ethical Treatment of Animals (PETA) poses for photos in a bath during a vegetarianism campaign ahead of Earth Day, in Mumbai, India, Tuesday, April 21, 2015. According to PETA, it takes more than 15,000 litres of water to produce 1 kilogram (2.2 pounds) of meat, the equivalent of taking 75 baths. (AP Photo/Rafiq Maqbool) (credit:ASSOCIATED PRESS)
Pakistan Earth Day(18 of21)
Open Image ModalA Pakistani woman washes vegetables with a polluted water at a canal in Lahore, Pakistan, Tuesday, April 21, 2015. Pakistan will observe the Earth Day on April 22, 2015. (AP Photo/K.M. Chaudary) (credit:ASSOCIATED PRESS)
Malaysia Anti Nuclear(19 of21)
Open Image ModalA protestor lies on the ground with an anti-nuclear placard covering his face during a protest in Bangi outside Kuala Lumpur, Malaysia on Tuesday, April 21, 2015. In conjunction with the World Earth Day on April 22, about a dozen protestors from the Malaysia Socialist Party gathered outside the Malaysia Nuclear Agency to protest the development plans of nuclear reactor in Malaysia. (AP Photo/Joshua Paul) (credit:ASSOCIATED PRESS)
Pakistan Earth Day(20 of21)
Open Image ModalPakistani children play in a stream polluted by sewerage from nearby localities, in a suburb of Islamabad, Pakistan, Tuesday, April 21, 2015. Pakistan will also observe the Earth Day on April 22, 2015. (AP Photo/B.K. Bangash) (credit:ASSOCIATED PRESS)
Pakistan Earth Day(21 of21)
Open Image ModalPakistani children play in a stream polluted by sewerage from nearby localities, in a suburb of Islamabad, Pakistan, Tuesday, April 21, 2015. Pakistan will also observe the Earth Day on April 22, 2015. (AP Photo/B.K. Bangash) (credit:ASSOCIATED PRESS)