African Temperatures According To GISS

 

 

According to GISS, Africa is one of the fastest warming places on the planet. But how reliable are their temperature records?

The first thing to notice is that the anomalies are based on the period 1950-1980, but if we look at a couple of long running South African stations, we immediately see the familiar story of a much cooler interlude between about 1940 and 1980.

 

 

 

 

So it would hardly be surprising to see that current temperatures are warmer than 1950-1980. Nevertheless we should surely be able to trust the temperature record in recent years. After all there are 538 African GHCN stations listed in the GISSTEMP record, so there ought to be a pretty good coverage across the continent. However, if you thought that you would be wrong.

I have analysed all of these stations to see which ones fulfil the following criteria :-

1) A  record from 1941 or earlier up to 2011. ( There are many stations with gaps in their record, but I have not excluded these).

2) No more than 20% missing data between 2001 and 2011.

Out of 538 stations, only 40 stations actually meet these two conditions. Furthermore, of these , 39 are urban / small towns, leaving just 1 rural station. Bear in mind, that according to GISS methodology, urban stations are only included in the GISS temperature analysis if there exists a nearby rural station so as to make adjustments for UHI. Therefore it would appear that the temperature analysis for most of Africa is based either on stations with a record not long enough to give proper long term trends or on stations with large gaps in their records in the last decade (or both!)

For interest the only rural station to meet the criteria is Calvinia, a small town in South Africa with a population of 8146. The temperature graph for Calvinia shows no apparent long term trend.

 

 

What of the rest?

So what about the other 498 stations? I wondered if I was being too selective in omitting stations which were only set up after 1941. To check this out, I carried out a fuller analysis on 50 stations from one page of the GISS subset, which in their own words “ contribute to the final products”. (This particular batch seems to centre around the area from Angola/Congo/Gabon in the west across to Kenya in the east – in other words a fairly typical swathe across Central Africa).

The analysis showed that :-

1) There were 29 urban/small towns and 21 rural stations.

2) Of the 21 rural stations, only 7 had records up to 2011. None of the others extended past 1991.

3) Of the 7 current stations, 6 had no records prior to 1987.

4) Amongst these 6 stations, at least 67% of the monthly temperature readings were missing for the period 2001-10. The missing records were even worse for 2006-10 with at least 75% missing in all cases.

5) To cap it all, the other station (the only rural station with records prior to 1987) is Garissa in Kenya. Although GISS list this as “rural”, it is in fact a large town with a population of 65000, and the weather station is at an airport. Even here, a full 50% of monthly records between 2006 and 2010 are missing.

It is abundantly clear that in most of Africa, the temperature record simply does not exist to allow continent wide analysis. Temperatures may have risen there in the last 30 years, but that should not allow GISS to make up numbers, if the actual data does not exist to prove it.