Climate Change

Aaron Brown | 2.5.2026 2:25 PM

Bloomberg columnist Mark Gongloff says this scary-looking chart is something "climate denialists can't ignore" because it shows how much hotter the world has been getting since 1930.

The chart should actually look like this.

How about this terrifying graph showing record warm temperatures?

It should look like this.

These are two examples of how climate scientists manipulate data to generate scary-looking charts. Global warming is real, but using statistical tricks to frighten people into panicking about it poisons the public discourse and leads to bad policy decisions. 

Both charts are known as hockey-stick graphs because they show a sharp, alarming upward trend in temperature. 

Here's the original hockey stick graph from 1998.

It was created by climate activist Michael Mann, who exploited widespread ignorance of physics and mathematics to advance his point. He refused to reveal his data and methodology. He grafted the scary red line on the right, unrelated to the data in the rest of the chart. He used a biased statistical method to stitch together unreliable proxy data, and the graph dramatically overstated the certainty of past temperatures. 

Here's the more recent hockey-stick chart I showed above, which was published by the U.S. government's Global Climate Change Research Program.

It measures record-high temperatures in the U.S. using ratios. The red lines show the ratio of record-high to record-low daily temperatures, and the blue lines show the ratio of record-low to record-high daily temperatures. If there were more record highs than record lows, you see a red line; if there were more record lows than record highs, you see a blue line. And the line's height is the ratio.

The only reason to present the data as a ratio is to create a scary visual in which the alarming-looking red lines get taller and taller. The chart is labeled "Record Warm Daily Temperatures Are Occurring More Often," but as the theoretical physicist Steven Koonin explained in his 2021 book Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters, that's not what it shows.

Koonin graphed the number of record warm days in the U.S. and, as........

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