"General Motors, a company that's made strides to lower the carbon footprint of driving, is taking heat from 10,000 of its customers for a donation its charitable foundation made to an institute that casts doubt on climate science."

"With efforts to reduce lead poisoning among children at a crossroads, Maryland lawmakers are wrestling with proposals to expand state regulation of home sales, rentals and repairs to reduce youngsters' exposure to the toxic metal."

"TALLAHASSEE — Federal environmental officials underestimated the cost of implementing their new water pollution rules for Florida, just as critics have been saying, a National Research Council panel concluded in a report released Tuesday."

"NIAGARA FALLS, N.Y. — Niagara Falls has gone on record against treating wastewater from hydraulic fracturing, with elected officials saying they don't want the city that endured the Love Canal toxic waste crisis to be a test case for the technology used in gas drilling operations."

"Senate Republicans' push for a vote on approval of the delayed $7 billion Keystone XL oil pipeline project gained momentum on Tuesday after Democrats failed to end debate on a major transportation bill.

Fifty-two senators, most of them Democrats, voted to move forward on the $160 billion highway bill without a proposed Republican amendment to authorize construction of the Canada-to-Texas pipeline, eight votes short of the 60 needed to end debate.

"An environmental scientist at Johns Hopkins University in Baltimore, Maryland, has resigned from the expert advisory committee intended to guide the US National Children’s Study (NCS), charging that the goals of the massive study, which aims to track factors affecting the health of 100,000 children from before birth to age 21, have been 'significantly abrogated' by its managers at the National Institutes of Health (NIH)."

"President Barack Obama said on Tuesday he is concerned about oil output around the world as gasoline prices soar and is looking to ease bottlenecks at U.S. refineries to help ease prices at home."

"From its perch in a spacious brand-new headquarters blocks from the White House, the Cato Institute has built on its reputation as a venerable libertarian research center unafraid to cross party lines. Now, however, a rift with one of its founding members — the billionaire conservative Charles Koch — is threatening the institute's identity and independence, its leaders say, and is exposing fault lines over Mr. Koch's aggressive and well-financed brand of Republican politics."

Coltan ore is valuable as a source of niobium and tantalum, metals key to many kinds of electronics. Coltan mining has helped finance war in places like the Democratic Republic of Congo. Now new illegal coltan mining activity has sprung up in the remote Amazon jungles on the border between Venezuela and Columbia. It is controlled largely by armed militias and drug smugglers.