US climate sees decline in both hot and cold extreme temperatures since 1899
phys.orgThe actual paper is by professional climate denialist John Cristy.
https://link.springer.com/article/10.1007/s00704-026-06200-3
Just because he's paid to do this doesn't make him wrong, but it does suggest that he's motivated to make certain kinds of errors. The discussion section is devoted to proving that climate change data is systematically skewed, which is weird given that his own lab handles the satellites and quite clearly shows increasing global temperatures. Cristy is the "climate change isn't so bad" kind of climate denier, not the "it isn't happening" kind.
He spends a lot of time describing data cleaning, but it's notable that extremes declined as data-collecting methods improved, then started increasing over the past several decades. An alternative hypothesis is that people collecting data by hand make more mistakes than computers and satellites.
The word decline in this headline is utterly ambiguous.
- Hot and cold tenps lowered
- Hot lowered and cold rose
- Extremes were less significant
- Extremes were more spikey
Then there's the nonsense figure of speech "US climate sees"
Finally, what's significant about 1899?
When a headline invokes a litany of questions that confuse or betray it, you've encountered clickbait noise.
The paper notes that 1899 was an extreme cold event -- an order of magnitude greater than average. Pick any other starting year and the trend becomes vastly smaller.
It's hard to tell if that's just bad data collection in 1899, perhaps a genuine cold snap exaggerated by data gatherers seeking extremes.
There's a similar magnitude of hot snap in 1936 that dwarfs every other one, and that's not simply cherry-picking on Christy's part, but it was confined to North America. Globally 1936 was not especially hot.
Regardless, as TFA says, "Extreme cold has decreased sharply." Cristy is trying to claim that extreme heat has also decreased, but I don't think he's evaluating the data critically.