Tuesday, December 1, 2009

When Results Go Bad...

from WUWT:

Coversation between Dr. Karlen and Climategate associated scientist Dr. Trenberth...

[Karlen] I have in my studies of temperatures also checked a number of areas using data from NASA. One, in my mind interesting study, includes all the 13 stations with long and decent continuously records north of 65 deg N.

The pattern is the same as for the Nordic countries. This diagram only shows 11-yr means of individual stations. A few stations such as Verhojans and Svalbard indicate a recent mean 11-year temperature increase up to 0.5 deg C above the late 1930s. Verhojansk, shows this increase but the

temperature has after the peak temperature decreased with about 0.3 deg C during the last few years. The majority of the stations show that the recent temperatures are similar to the one in the late 1930s.

In preparation of some talks I have been invited to give, I have expanded the Nordic area both west and east. The area of similar change in climate is vast. Only a few stations near Bering Strait deviates (e.g. St Paul, Kodiak, Nome, located south of 65 deg. N).

My studies include Africa, a study which took me most of a summer because there are a large number of stations in the NASA records.  I found 11 stations including data from 1898-1975 and 16 stations including 1950-2003.

The data sets could in a convincing way be spliced. However, I noticed that some persons were not familiar with ’splicing’ technique so I have accepted to reduce the study to the 7 stations including data from the whole period between 1898-2003. The results are similar as to the spliced data set and

also, surprisingly similar to the variability of the Nordic data.

Regression indicates a minor (if any) decrease in temperature (I have used all stations independent of location, city location or not).

[Trenberth] Africa is notorious for missing and inaccurate data and needs careful assessment.

[Karlen] Another example is Australia. NASA only presents 3 stations covering the period 1897-1992. What kind of data is the IPCC Australia diagram based on?

If any trend it is a slight cooling. However, if a shorter period

(1949-2005) is used, the temperature has increased substantially.

The Australians have many stations and have published more detailed maps

of changes and trends.

There are more examples, but I think this is much enough for my present

point:

How has the laboratories feeding IPCC with temperature records selected stations?

[Trenberth] See our chapter and the appendices.

[My comment] I have looked at these. The source for Fig. 9.1.2 is given as “(HadCRUT3; Brohan et al., 2006)”. HadCRUT3 is produced jointly by CRU and the Hadley Centre.

[Karlen] I have noticed that major cities often demonstrate a major urban effect (Buenos Aires, Osaka, New York Central Park, etc). Have data from major cities been used by the laboratories sending data to IPCC?  Lennart Bengtsson and other claims that the urban effect is accounted for but from what I read, it seems like the technique used has been a simplistic

[Trenberth] Major inner cities are excluded: their climate change is real but very

local.

[My comment] It is true that the IPCC Chapter 3 FAQ says this:

Additional warming occurs in cities and urban areas (often referred to as the urban heat island effect), but is confined in spatial extent, and its effects are allowed for both by excluding as many of the affected sites as possible from the global temperature data and by increasing the error range (the blue band in the figure).

To check this claim, I took the list of temperature stations used by CRU (which I had to use an FOI to get), and checked them against the GISS list. The GISS list categorizes stations as “Urban” or “Rural”. It also uses satellite photos to categorize the amount of light that shows at night, with big cities being brightest. It puts them into three categories, A, B, and C. C is the brightest.

It turns out that there are over 500 cities in the CRU database that the GISS database categorizes as “Urban C”, the brightest of cities. These include, among many others:

AUCKLAND, NEW ZEALAND

BANGKOK METROPOLIS, THAILAND

BARCELONA, SPAIN

BEIJING, CHINA

BRASILIA, BRAZIL

BRISBANE, AUSTRALIA

BUENOS AIRES, ARGENTINA

CHRISTCHURCH, NEW ZEALAND

DHAKA, BANGLADESH

FLORENCE, ITALY

GLASGOW, UK

GUATEMALA CITY, GUATEMALA

HANNOVER, GERMANY

INCHON, KOREA

KHARTOUM, SUDAN

KYOTO, JAPAN

LISBON, PORTUGAL

LUXOR, EGYPT

MARRAKECH, MOROCCO

MOMBASA, KENYA

MOSKVA, RUSSIAN FEDERA

MOSUL, IRAQ

NAGASAKI, JAPAN

NAGOYA, JAPAN

NICE, FRANCE

OSAKA, JAPAN

PRETORIA, SOUTH AFRICA

RIYADH, SAUDI ARABIA

SAO PAULO, BRAZIL

SEOUL, KOREA

SHANGHAI, CHINA

SINGAPORE, SINGAPORE

STOCKHOLM, SWEDEN

TEGUCIGALPA, HONDURAS

TOKYO, JAPAN

VALENCIA, SPAIN

VOLGOGRAD, USSR

So the CRU is using Tokyo? Beijing? Seoul? Shanghai? Moscow? Their claim is entirely false. In other words, once again the good folk of the CRU are blowing smoke. I can understand why it took me a Freedom of Information request to get the station list.