I don’t know how realistic his time predictions are, given how few years he’s extrapolating from, but his overall concern seems very realistic to me. Especially with the earth dimming over the last decade.

Record global temperature in 2023 helps reveal acceleration of global warming on decadal time scales. The proximate cause of the acceleration is increase of Earth’s energy imbalance, specifically a substantial darkening of the planet (decreased albedo) equivalent to a CO2 increase of more than 100 ppm -The paper where James Hansen says that

This fact alone is terrifying to me. I don’t know if there is a reason to think it will slow. La Nina is weak, and not lowering temperatures.

“astonishing and frankly terrifying” that January remained at record highs despite a La Niña emerging.

This is what makes it a bit of a surprise: you’re not seeing this cooling effect, or temporary brake at least, on the global temperature that we were expecting to see.

The brakes are burning out. A massive change is happening. I really believe the earth is dying. I have been crying off and on since seeing this analysis. If the next decade really is as bad as the last five years have been, a lot of people will die. Even if it takes twice as long, three times, it will still happen. In front of me. I will watch everything be destroyed. This is the peak of human civilization. So, so many people are going to die.