"The holy grail of space exploration is to find extraterrestrial life. An important precursor to that is finding liquid water—and that's exactly what NASA [Monday] announced scientists have discovered on Mars."

"Volkswagen’s diesel deception unleashed tons of extra pollutants in the United States, pollutants that can harm human health. So while many commentators have been quick to say that the cheating engines are not a highway safety concern, safety — as in health — is still an issue."

"The Environmental Protection Agency (EPA) is moving forward with new rules to ensure that shipments of hazardous waste are safely imported and exported."

"Donald Trump was succinct last week when asked how the United States should respond to climate change. 'It's not a big problem at all,' the leader in opinion polls for the Republican presidential nomination told a radio talk show host. 'If you look at China, they're doing nothing about it.'"

"While differences on cyber security and talk of sanctions dominated the headlines for Chinese president Xi Jinping’s visit to the US, the two countries also signed up to a major agreement to end the global trade in ivory."

"The pledges that countries are making to battle climate change would still allow the world to heat up by more than 6 degrees Fahrenheit, a new analysis shows, a level that scientists say is likely to produce catastrophes ranging from food shortages to widespread extinctions of plant and animal life."

"Pope Francis told world leaders on Friday that in order to address poverty, hunger, war and inequality, they must first tackle climate change."

"Volkswagen AG's upmarket Audi brand says 2.1 million of its vehicles are among those with the engines affected by the emissions-rigging scandal."

"SEATTLE – In a meeting with Chinese President Xi Jinping, a bipartisan group of five U.S. governors Tuesday signed an accord with six Chinese governors to promote clean energy technology and economic development."

"Russia has rebuffed calls for a more ambitious plan to cut its carbon dioxide emissions after environmentalists branded its current pledge inadequate and backward-looking."