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Showing posts with the label pause

How Have Contrarian Climate Predictions Performed?

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If you follow popular discussions about AGW, you'll likely see many claims that climate scientists have been making terrible predictions and climate models invariably run too hot compared to observations. If you investigate these, almost all of so-called "predictions" of climate scientists turn out to be some combination of misinformed assessments by media personalities, reporters and politicians or claims by scientists that have been misread by contrarians. And while it's true that some climate scientists have said some things that have not panned out, this is clearly the exception, not the rule. In fact, overall, climate scientists have been slightly conservative with their predictions, and climate model have performed quite well.[1] In fact, Zeke Hausfather has done a pretty good job of tracking how model predictions compare to observations, and overall, they've done quite well. So given all the rancor from contrarians about the predictions of climate scientist...

Type II Errors in Conclusions from Short-Term Trends

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95% CI Envelope for HadCRUT4 in McKitrick's Paper In a recent post , I shared why making conclusions from short-term trends is misleading. It's the kind of mistake that people make on social media, but I didn't think that I would find it in the scientific literature.  But in 2014, Ross McKitrick published a paper attempting to develop a statistical method for determining the length of the so-called "pause" in global warming through 2014. To do this, McKitrick calculated trends with 95% CIs through 2014 in 3 datasets - HadCRUT4, RSS and UAH. The lower bound CI overlapped 0 C/decade in 1995 for HadCRUT4, 1998 for UAH and 1988 for RSS. McKitrick then says these dates can give us the length of the "pause" in global warming. His words: I propose a robust definition for the length of the pause in the warming trend over the closing subsample of surface and lower tropospheric data sets. The length term J MAX is defined as the maximum duration J for which a vali...