China and the United States ready to sign the Paris climate agreement

The planet has just experienced the warmest winter on record, with temperatures at the North Pole approaching zero degrees: unprecedented. And that's the glass half empty. The half-full glass is that Chinese President Xi Jinping and US President Barack Obama announced that they would sign the Paris climate agreement on the first day of its official presentation. The two biggest polluters on Earth - 40% of carbon dioxide emissions - confirm their commitment.