Alexandria leaders are about to take a formal position against the expansion of operations at a hazardous materials facility.

Demand for rhino horn, used in traditional Chinese medicine, is fueling a slaughter of the animals in Africa. In Vietnam, the sought-after commodity is fetching prices as high as $1,400 an ounce, or about the price of gold. There, some believe ground horn can cure everything from hangovers to cancer.

Treated human waste has been used on farmland for decades, but the ick factor has not entirely faded. Some environmentalists think the treatment process may not get rid of all the harmful contaminants that could be in the waste.

Saturday is the opening of the walleye fishing season, and it's usually one of the busiest weekends for the state's resort communities. This year, many of the lakes in northern Minnesota are still iced over, putting a chill on the season.

Since 1958, researchers have been measuring the amount of carbon dioxide in the atmosphere at the Mauna Loa Observatory. The remote outpost has just reported a carbon dioxide level of 400 parts per million — the highest it has climbed in the modern age.

The amount of carbon dioxide in the atmosphere has crossed the "psychological threshold" of 400 parts per million. That number is one of the clearest measures of how humans are changing the planet by burning fossil fuels.