1.5 Degrees Is Dead, and COP31 Diplomats Know It

The slogan that rallied climate campaigners for a decade — keep 1.5 alive — got a burial at the United Nations summit in Antalya, Turkey. Chris Bowen, Australia's minister for climate change and energy and the official steering the COP31 negotiations, did not soften it: the world, he said, cannot hold warming to 1.5 degrees Celsius. Diplomats who spent years defending the number instead spent the summit mourning it.

The target dates to 2015, when nearly every country signed the Paris Agreement and pledged to try to cap warming at 1.5 degrees Celsius above preindustrial levels. Eleven years later, scientists say that without severe greenhouse gas reductions, the planet is very likely to heat by at least 2.6 degrees Celsius — 4.7 degrees Fahrenheit — by the end of the century.

Researchers have long warned what the gap costs. Past 1.5 degrees, extreme heat turns more frequent and more brutal, storms pack more force, seas climb, and poorer nations absorb the worst of it. That bill is already arriving: wildfires have burned from Canada to Indonesia, floods and mudslides have wrecked Brazil, and a European heat wave is estimated to have killed 50,000 people.

Nepal delivered the grimmest example. A glacier there collapsed, killing thousands and erasing entire towns, according to The New York Times. The summit in Turkey now carries the argument over what replaces a target that no longer functions.