Hausfather conducted an analysis of what a 1963-level eruption would mean for the global average temperature. It shows that the planet would likely cool 0.1-0.2 degrees Celsius with the peak cool period coming around 2019. A weak La Niña that’s expected to last into the spring of next year could have also have a limited chilling effect on the planet.


Of course, “cool” is used relatively. In Hausfather’s analysis, 2019 would be the coolest of the post-Agung eruption years, but it would still rank as one of the five warmest years on record. That’s because Agung’s sulphur dioxide is far outweighed by the warming influence of all the carbon dioxide humans have added to the atmosphere. It’s like dropping an ice cube into a pot of water boiling on the stove.

Now if the volcano under Yellowstone decides to erupt, that’s another story. But don’t get your hopes up.