Dr. Syun Akasofu on IPCC's forecast accuracy

UPDATE#2 I finally found a graph from Professor Akasofu that goes with the text of his essay below. I’ve added it above.  You can read more about Akasofu’s views on climate in this PDF document here. (Warning: LARGE 50 megabyte file, long download) The two previous graphs used are in links below.

UPDATE: Originally I posted a graph from Roger Pielke Jr. see here via Lucia at the Blackboard because it was somewhat related and I wanted to give her some traffic. As luck would have it, few people followed the link to see what it was all about, preferring to question the graph in the context of the article below. So, I’ve replaced it with one from another article of hers that should not generate as many questions. Or will it? 😉 – Anthony

THE IPCC’S FAILURE OF PREDICTING THE TEMPERATURE CHANGE DURING THE FIRST DECADE

Syun Akasofu

International Arctic Research Center

University of Alaska Fairbanks

Fairbanks, AK 99775-7340

The global average temperature stopped increasing after 2000 against the IPCC’s prediction of continued rapid increase. It is a plain fact and does not require any pretext. Their failure stems from the fact that the IPCC emphasized the greenhouse effect of CO2 by slighting the natural causes of temperature changes.

The changes of the global average temperature during the last century and the first decade of the present century can mostly be explained by two natural causes, a linear increase which began in about 1800 and the multi-decadal oscillation superposed on the linear increase.  There is not much need for introducing the CO2 effect in the temperature changes. The linear increase is the recovery (warming) from the Little Ice Age (LIA), which the earth experienced from about 1400 to 1800.

The halting of the temperature rise during the first decade of the present century can naturally be explained by the fact that the linear increase has been overwhelmed by the superposed multi-decadal oscillation which peaked in about 2000.*

This situation is very similar to the multi-decadal temperature decrease from 1940 to 1975 after the rise from 1910 to 1940 (in spite of the fact that CO2 increased rapidly after 1946); it was predicted at that time that a new Big Ice Age was on its way.

The IPCC seems to imply that the halting is a temporary one.  However, they cannot give the reason.  Several recent trends, including the phase of the Pacific Decadal Oscillation (PDO), the halting of sea level increase, and the cooling of the Arctic Ocean, indicate that the halting is likely to be due to the multi-decadal change.

The high temperatures predicted by the IPCC in 2100 (+2~6°C) are simply an extension of the observed increase from 1975 to 2000, which was caused mainly by the multi-decadal oscillation.  The Global Climate Models (GCMs) are programmed to reproduce the observed increase from 1975 to 2000 in terms of the CO2 effect and to extend the reproduced curve to 2100.

It is advised that the IPCC recognize at least the failure of their prediction even during the first decade of the present century; a prediction is supposed to become less accurate for the longer future.

For details, see http://people.iarc.uaf.edu/~sakasofu

* The linear increase has a rate of ~ +0.5°C/100 years, while the multi-decadal oscillation has an amplitude of ~0.2°C and period of ~ 50-60 years, thus the change in 10 years is about ~ -0.07°C from the peak, while the linear change is about ~ +0.05°C.