"It was a controversial move when Madison, Wis., decided to replace all its lead pipes in 2001. But that decision put the city ahead of the curve — allowing it to avoid the lead water contamination that is plaguing cities like Flint, Mich., now."

"Hidden beneath Boston lies a vast network of aging iron and steel pipes that leak natural gas from thousands of points under the city. A small number of these leaks emit large volumes of methane, a potent greenhouse gas, while others pose an immediate explosion hazard, according to a recent peer-reviewed study published in the journal Environmental Pollution."

"U.S. health regulators are facing a lawsuit from a coalition of environmental organizations seeking to overturn the government's landmark approval of a type of genetically engineered salmon to be farmed for human consumption."

"President Obama and President Xi Jinping of China said Thursday that they would sign the Paris Agreement on climate change on April 22, the first day the United Nations accord will be open for government signatures."

"Americans trying to kick their soda habit are succeeding, with soda consumption in the U.S. at its lowest level in 30 years, according to a new report."

"MEXICO CITY — Metropolitan authorities on Wednesday temporarily ordered all cars to remain idle one day a week in response to this notoriously smoggy capital's worst air-quality crisis in over a decade."

"The Obama administration on Wednesday announced a new partnership with 41 energy companies that have agreed to voluntarily reduce methane emissions from natural gas operations to help combat climate change."

"New study says at least 39 fracked wells in Alberta and British Columbia likely triggered earthquakes in recent years."

"Donald Trump and Ted Cruz oppose a carbon tax, putting them in league with the Republican National Committee on the issue but at odds with some oil companies and economists who view a levy on those heat-trapping emissions as an effective way to combat climate change."

"A new report from six health and environmental groups finds 67 percent of nearly 200 food cans from dozens of brands and retailers tested positive for Bisphenol A, a hormone-disrupting chemical linked to increased risk of breast and prostate cancers, infertility and type-2 diabetes."