Paris Conundrum: How to Know How Much Carbon Is Being Emitted?

As climate negotiators consider rules for verifying commitments under the Paris Agreement, they will have to confront a difficult truth: There currently is no reliably accurate way to measure total global emissions or how much CO2 is coming from individual nations.

PCB pollution threatens to wipe out killer whales

More than 40 years after the first initiatives were taken to ban the use of PCBs, the chemical pollutants remain a deadly threat to animals at the top of the food chain. A new study shows that the current concentrations of PCBs can lead to the disappearance of half of the world’s populations of killer whales from the most heavily contaminated areas within a period of just 30-50 years.