Why it matters: The climate of 2023 was the hottest seen in at least 125,000 years; for the first time in instrument records, daily global average temperatures went well above the other Paris guardrail of 2°C.
Driving the news: Data released Tuesday morning from Europe’s Copernicus Climate Change Service lays out just how many significant climate records were surpassed during 2023, amplified mainly by burning fossil fuels for energy.
The intrigue: Last year’s heat raises questions among scientists about whether climate change has accelerated, or even passed a tipping point. It started with a cooling La Niña event in the tropical Pacific Ocean and ended with a strong El Niño.
- El Niño events serve as added warming influences on top of human-caused climate change. But not even El Niño could fully explain the unusual warmth of 2023.
- Neither do other factors, such as the2022 eruption of the Hunga Tonga-Hunga Ha’apai volcano in the South Pacific. That sent massive amounts of water vapor into the stratosphere that could be adding to short-term warming.
- One other suspect is the reduction of aerosol emissions from global marine shipping, but this too is thought to have contributed only a small amount to climate change during 2023.