Global Warming Reached +1.53°C in 2024
- Thomas Neuburger
- 2 hours ago
- 4 min read
By Thomas Neuburger
“Courage is the resolve to do well without the assurance of a happy ending.” —Climate scientist Kate Marvel here
To measure global warming, one needs a baseline. The IPCC, in its wisdom, has defined “pre-industrial temperature” as the average of the years 1850-1900, partly because these are the first years of the modern instrumental record, and partly for political purposes. (The higher the baseline, the less we’ll be moved to action, which benefits the nations controlling the IPCC.)
I’ve long maintained that what the IPCC has been calling its pre-industrial baseline is way too high. In a January 2017 piece, for example, “Global Warming Has Reached Nearly +1.5°C Already,” I argued that there’s about 0.2°C of warming undeclared in the accepted baseline number.
After all, the Industrial Age is generally said to start with the invention of James Watt's steam engine in the 1700s. (The patent date is 1769.) More than half a century of steam-powered, coal-fueled “industry” occurred before 1850.
The conclusion, that we’re ahead of the Paris agreement schedule, is sobering. Again, from 2017, almost a decade ago:
Two points: • The Paris climate agreement had hoped to hold global warming to no more than +1.5°C above the pre-Industrial temperature. This is not going to happen. We're almost at that point now, and we'll breach that goal in just a few years. • From the chart at the top, note that the two-year rise from 2014 to 2016 was, converted to Celsius, +0.1 degrees all on its own. Three more two-year periods like this and global temperatures will cross +2°C, the extremely generous IPCC "magic barrier" after which, in lay language, "we're mainly screwed." This doesn't mean we should do nothing to adapt to the blow — it's always necessary and wise to adapt, even if the start of adaptation is very late. But the window to mitigate — to lessen the blow — is rapidly closing. Remember, once the social and political chaos reaches critical mass (once there's too much of it), global warming will run to its natural conclusion. Elsewhere I've predicted the "natural conclusion," barring conscious intervention, to be global warming of +7°C before humans are forced to stop emitting so much CO2, either through greatly diminished numbers, or greatly diminished technology, or both.
Again, this was written in 2017. By the way, my +7°C prediction from more than a decade ago (2013) is here, along with the reasoning behind it.
New Evidence for a Lower ‘Pre-Industrial Baseline’
Recall that the period 1850-1900 was chosen in part because it conforms to the instrumental record. But not long ago, two scientists in the UK, Andrew Jarvis and Piers Forster, have devised a well-constructed proxy for pre-industrial temperature, using CO2 concentration found in East Antarctica ice cores.
The method is complex, but not incomprehensible. Their original paper was published in Nature Geoscience, one of the premier climate publications:
They applied their method both to the instrumental data from 1850 to 1900, and to the period starting at 13 CE through the 1800s. The correlation between their method’s temperature predictions and the instrumental record is high, with the added benefit that theirs has a greater degree of accuracy (a narrower uncertainty band). This gives confidence about their pre-instrumental conclusions.
‘Pre-Industrial’ Temperatures and Existing Global Warming
Their conclusions are clear. Baked into the 1850-1900 data is additional warming. From a report on the paper at Jarvis’s Lancaster University:
The authors find that when measured from this earlier more accurate definition of pre-industrial time, the long-term human contribution to warming was 1.49 °C ± 0.11 °C in 2023 and is now above 1.5 °C. This reveals that there is almost 0.2 °C of warming within the 1850-1900 baseline currently being used to define the warming.
This is using 2023 data. In an interview, Jarvis said that using CO2 data from October, their method shows human-induced warming had hit +1.53°C.
What to Do? What We Would Do Anyway. Live Courageously.
Since we’re not going to stop, not under anyone’s rule...
...we’re headed to what I called above the “natural conclusion.”
As to what to do, consider: Since global warming has clearly accelerated, and since we’ve limited time and money to use in response, we should shift our efforts from mitigation (making the world less unfriendly) to adaptation (making ourselves more resilient).
If we can’t change the world, we can still adapt to it — a task that can be attempted at any level, individually, in families, or larger.
And, like in every day of our fragile lives, we can face the one coming with courage. Or, as the ancient American philosopher Tom Waits wrote (Willie Nelson's dramatic reading here):
All your cryin' don't do no good Come on up to the house Come down off the cross, we can use the wood Come on up to the house
We can definitely use the wood, and another hand to help carry it.