"Opponents of the Keystone XL pipeline and the heavy Canadian crude oil that it would carry released two reports on Thursday asserting that the environmental impacts of the project are worse than previously estimated, and urged the Obama administration to veto it."

"A new method for monitoring the decline in bee populations may prove a useful tool in much-needed conservation efforts. It requires only a few hundred pan traps: bright shallow bowls partly filled with soapy water or propylene glycol."

"A carcinogenic mold, its growth exacerbated by the warming climate, reached record highs in 2012."

"Leaked documents reveal the government has sought to change proposals that could prevent deepsea drilling operations."

"NASA and NOAA scientists say 2012 global temperature records further consolidate a pattern of global warming."

"Black carbon, the soot produced by burning fossil fuels and biomass, is a more potent atmospheric pollutant than previously thought, according to a four-year international study released on Tuesday."

"GENEVA — Delegates from more than 130 nations began a final round of negotiations on Sunday that are expected to lead to the creation of the first legally binding international treaty to reduce mercury emissions."

"The world could avoid much of the damaging effects of climate change this century if greenhouse gas emissions are curbed more sharply, research showed on Sunday."

"The Pacific bluefin tuna, fished relentlessly for decades, is in trouble."

"GENEVA -- Mercury pollution in the top layer of the world's oceans has doubled in the past century, part of a man-made problem that will require international cooperation to fix, the U.N.'s environment agency said Thursday."