Matt Rourke / AP fileEnvironmentMassive oil refinery leaks toxic chemical in the middle of Philadelphia
Zakaria Abdelkafi / AFP - Getty Images fileClimate in CrisisThe last decade was the warmest on record, NASA and NOAA find
Asanka Brendon Ratnayake / AFP - Getty ImagesHealth newsAustralian wildfire smoke stokes health fears in cities
Galapagos National Park via APAnimal NewsGiant tortoise who helped save species retires in Galapagos Islands
Aidan Morrison / via ReutersEnvironment'Fire clouds': After Australia, scientists warn the erratic weather phenomenon could become a new reality
Janaina N. AvilaSpaceBuried in a meteorite, 7 billion-year-old stardust is oldest material found on Earth
NOAAClimate in Crisis'Weather on steroids': Earth's warming oceans store energy for destructive storms
Robert Markowitz / NASA - Johnson Space CenterSpaceNASA graduates new class of astronauts for missions to the moon, Mars
Tracey Nearmy / ReutersClimate in Crisis'It was like midnight': Australia's wildfires spur health concerns over smoke
Evan Vucci / APClimate in CrisisTrump proposes massive environmental rollback to speed approval process
Steve Helber / AP fileClimate in Crisis'We're fighting for our lives': Activists in pipeline station battle score major victory
Lisa Maree Williams / Getty ImagesClimate in CrisisScientist estimates a billion animals killed by Australian wildfires
Saeed Khan / AFP - Getty ImagesClimate in CrisisRare and dangerous weather phenomena in Australia as wildfires rage