> Today’s infrared thermometers for fevers have a 2F accuracy. You’re telling me that you can calculate temperatures from around the world pre-1950s and trust that it’s consistent and accurate?

Yes. Believe it or not, the average of multiple calibrated measurements is more accurate than some random off the shelf consumer electronics. My laptop display has a delta E of about 20 out of the box. If someone calibrates it they could bring it down to 5, most likely. I have no trouble believing an actually decent panel can achieve less than 3.

I can probably finagle a way of measuring haemoglobin with my kitchen equipment and some reagents I order off eBay. I might even get one sig fig out of that. That doesn't mean the literal bottom shelf crap I use is going to be the absolute limit of possible precision.

I mean, what kind of argument even is that? "I can't make similar measurements using the equipment I have at home, therefore climate scientists must have either no idea what error bars are or are lying"?