Robert Rohde, at Berkley Earth published the annual summary for 2024 on January 10th, 2025. You can find it [here]

The Berkley analysis finds the year’s mean to be 1.62℃ above the 1850-1900 average. The other five main centres have provisional numbers a bit lower:

Rohde explains that most of this discrepancy is due, not to methodological differences, so much as the baseline estimate. Obviously, meteorological records over a century old leave a lot to be desired, and it takes some judgement to reconcile them. You can see how much the early records diverge here:

The record makes it clear that the analyses since 1960 have been in very close agreement - even though they use independent approaches to treatment of the data. If the records are aligned so the baseline periods coincide, however, it’s easy to see how the current differences arise:

Just to get an idea how anomalous the last two years have been, this plot shows the last ten years, plus a few earlier ones, with their measurement uncertainties:

And this shows how far the warming trend defined by greenhouse gas forcing has risen from its path in those two years - strongly suggesting an additional cause:

Here you see how the warming rates of land and ocean surface are drawing apart. We expect land to warm faster than water because of their very different heat capacities - but the trend should concern us because, while all our political goals are stated as ‘global mean surface temperature’ (GMST), it’s obviously the land temperature, where we all live that really matters. That’s where heat waves happen; that’s where soil evaporation, crop desiccation, and lightning-ignited wildfires happen. It’s what really counts as a human hazard.

Rohde discusses the evolving understanding of what combination of factors has caused the 2023-4 anomaly, without coming to any final conclusion. Like a good scientist, he concedes we will have to wait for longer observations and more investigation into each of the putative causes before we know. What is clear though, is that the planet has been taking in more solar energy, and that this trend has been increasing the planetary energy imbalance over the last 25 years, and specially the last decade or so. The imbalance is the distance between the red and blue sloping lines. As discussed in Chapter 2, the warming Earth is constantly adjusting its imbalance by raising its output of infra-red heat - that’s why the blue line is rising. But the further those quantities deviate, the longer it takes for the balance to return - under any circumstances whatsoever.

If the change in energy imbalance is mapped by large regions, you can see how there is a major contribution to surface albedo decline from the reduction of Antarctic sea ice in the last few years - something like 2 million km² in 2023-4 in the winter maximum. The Arctic has a smaller anomaly from the same cause, while the increases over the ocean, specially the North Atlantic & North Pacific may be related to aerosol reductions there.