The week began with a biting cold snap that hammered much of the U.S., the product of a jet stream that slips out of its usual path more often these days.

The European climate agency says for the eighth straight month in January, Earth was record hot.

Scientists say the annual peak of global heat-trapping carbon dioxide in the air has reached another dangerous milestone: 50% higher than when the industrial age began.

Activists of the so-called "KoalaKollektiv", an organization asking for climate justice, protested with the burning of the globe against the ECB's climate policy. (AP Photo/Michael Probst)BERLIN – The United States on Wednesday formally left the Paris Agreement, a global pact it helped forge five years ago to avert the threat of catastrophic climate change. “There is no greater responsibility than protecting our planet and people from the threat of climate change,” the statement said. Germany, which currently holds the EU's rotating presidency, said it was important for Europe to lead by example now that the United States had left the pact. In addition to condemnation from abroad, environmental and public health groups in the United States criticized Wednesday’s withdrawal.