We need to go beyond net zero to reverse catastrophic climate damage

WHEN it comes to global warming, every notch on the thermometer is vital. But one temperature rise has been etched into our minds for years: 1.5°C above pre-industrial levels. Passing this threshold may trigger multiple climate “tipping points” that could change the planet irreversibly. The arrival of an El Niño weather event and our poor efforts at cutting greenhouse gas emissions mean we could exceed 1.5°C of warming as soon as next year. This is “uncharted territory” for Earth’s climate, warns the World Meteorological Organization.

Uncharted, perhaps, but certainly not unknown. For years, scientists have been studying …