"Hollywood actor and environmental activist Leonardo DiCaprio has been named a United Nations Messenger of Peace, a post he will use to raise awareness about climate change, U.N. Secretary-General Ban Ki-moon said on Tuesday."

"The Senate confirmed two of President Obama’s nominees to the Nuclear Regulatory Commission on Tuesday."

"A week before major UN talks on climate change, EPA extends comment period for rule to cut carbon pollution from plants."

"The Obama administration on Tuesday announced a series of moves aimed at cutting emissions of hydrofluorocarbons, or HFCs, powerful greenhouse gases that contribute to climate change."

"A United Nations chief dismayed at the lack of resolve toward the climate crisis; a daunting deadline for negotiating a new treaty; 125 or so heads of state; a sprawling agenda of fossil fuels, food, forestry and finance; a train of think tanks hauling gigabytes of green data; countless teach-ins, press conferences, art shows—plus tens or even hundreds of thousands of activists marching through midtown Manhattan, demanding action now."

"Agriculture experts raised a number of concerns with genetically modified crops, including safety and spreading weed resistance, at the first public meeting of a U.S. government sponsored study of genetically engineered crops held Monday."

"Problems with natural gas well construction appears to be the primary cause of drinking water contamination from shale-gas extraction, according to a new study published today by researchers from five universities."

"Coal miners in Kentucky and other parts of Appalachia are contracting serious cases of black lung disease at rates not seen since the early 1970s — just after preventive regulations were enacted, according to a study published Monday."

"Major U.S. poultry firms are administering antibiotics to their flocks far more pervasively than regulators realize, posing a potential risk to human health."