The Pause - fun and games in the 2010s

[GregLocock]

First a bit of light reading

https://journals.ametsoc.org/view/journals/bams/97/5/bams-d-14-00106.1.xml

So, all these scientists seemed to think it was a significant event.

But if they had merely looked at the temperature record and applied a tiny little bit of high school maths they'd have found that pauses are more common than not. But they didn't. In fact since 1950 only a small proportion of the years have been pause free. So the algorithm works by starting with an end date and then finding the start date that results in a 0 slope line. The height of the pause line is the average temperature during that pause. The red dot is the 1998 peak in temperature that anchored the pause that got all the attention. And I'll admit it took more than 10 minutes to write the script for this graph, most of it was turning tables into vectors. Temperature data is HadCrut5 global by month. For the sake of speed I decremented the end date by year instead of month.

 

[GregLocock]

Incidentally you may be wondering why the 1998-2010 'Pause' is so short. That's because I used HadCRUT 5, which is significantly warmer than HadCRUT4 which is significantly warmer than HadCRUT 3

Yeah, right

and if you compare HadCRUT 5 to the satellite UAH data, well, no surprises

HadCRUT 5 is running 30% warmer than the satellite. Although it is tempting to call both temperature sets data, they aren't really, they are models of the data. H5 in particular uses kriging to extrapolate temperatures into unmeasured locations, which causes a warming effect, and also uses corrections for weather stations and their neighbors, which spreads UHI out into rural areas (for some reason these corrections always end up as an increase recent temperatures). UAH is measuring the temperature (kinda sorta) of the lower troposphere, great, but we live at the bottom of the lower troposphere, not in its average. The HadSST trend is the sea temperature trend, HadCRUT is a weighted average of the sea and the land series, so it seems likely there is something inherently optimistic/pessimistic in the land series. All of the main surface temperature series now use the same input data and the same modelling algorithms, hence they all agree with HadCRUT 5 bar a few mistakes here and there.

 

[GregLocock]

And just a little more, effect of making up data, or infilling, or kriging. You guessed it, 7% increase in the temperature trend.


The big effect of kriging may not surprise you when we look at the valid grid points for HadCRUT 3 - so the chances are good that all the white bits are interpolated/extrapolated/guessed in H5

 

[dik]

Why am I in this hqndbasket, and where am I going?

 

[GregLocock]

We're coming out of an Ice Age. The earth is therefore warming and the ice caps are retreating. More plants are growing. You are in an elevator not a handbasket.