HadCRUT, Numbers 4 And 5

Guest Post by Willis Eschenbach

The HadCRUT record is one of several main estimates of the historical variation in global average surface temperature. It’s kept by the good folks at the University of East Anglia, home of the Climategate scandal.

Periodically, they update the HadCRUT data. They’ve just done so again, going from HadCRUT4 to HadCRUT5.

So to check if you’ve been following the climate lunacy, here’s a pop quiz. What did the new record do to the HadCRUT historical temperature trend?

It decreased the trend, or

It increased the trend?

Yep, you’re right … it increased the trend. You’re as shocked by that as I am, I can tell.

So … here’s the old record and the new record.

Figure 1. HadCRUT4 and HadCRUT5 temperature records. The yellow/black and blue/black lines are lowess smooths of each dataset.

Let’s take a closer look at the changes. Here are just the lowess smooths, which give us a clear view of the underlying adjustments. I’ve added the University of Alabama Huntsville microwave sounding unit temperature of the lower troposphere (UAH MSU TLT) for comparison.

Figure 1. Lowess smooths of HadCRUT4 and HadCRUT5 surface temperature records, and the UAH MSU satellite lower troposphere temperature record. The yellow/black, blue/black, and orange/black lines are lowess smooths of each dataset. The red/black line shows the adjustments made to the HadCRUT4 dataset.

There were a couple of surprises in this for me. Normally, the adjustments are made on the older data and reflect things like changes in the time of observations of the data, or new overlooked older records added to the dataset. In this case, on the other hand, the largest adjustments are to the most recent data …

Also, in the past adjustments have tended to reduce the drop in temperature from ~ 1942 to 1970. But these adjustments increased the drop.

Go figure.

Anyhow, that’s the latest chapter in the famous game called “Can you keep up with the temperature adjustments”. I have no big conclusions, other than that at this rate the temperature trend will double by 2050, not from CO2, but from continued endless upwards adjustments …

After I voted today (no on tax increases), the gorgeous ex-fiancee and I spent the afternoon wandering the docks down at Porto Bodega, and looking at a bunch of boats that I’m very happy that I don’t own. She and I used to fish commercially out of that marina, lots of great memories.

My best regards to all,


Like this:

Like Loading…


via Watts Up With That?


March 3, 2021 at 12:05PM

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s