Guest Weblog By Syun-Ichi Akasofu – Global Warming And The Little Ice Age

Dr. Syun-Ichi Akasofu has been the Director of the International Arctic Research Center of the University of Alaska Fairbanks since its establishment in 1998. He has been Professor of Geophysics since 1964. Dr. Akasofu has published more than 550 professional journal articles, authored and co-authored 10 books and has been the invited author of many encyclopedia articles. He has collaborated with numerous colleagues nationally and internationally, and has guided nine students to their Ph.D. degrees.

He is certainly well qualified scientifically to present his perspective on climate change. He has completed several articles on this subject; e.g.

Why has “global warmingâ€? become such a passionate subject?
– Let’s not lose our cool –

Is the Earth still recovering from the “Little Ice Ageâ€??
A possible cause of global warming

His contribution as a guest weblog follows:

Global Warming and the Little Ice Age

Many studies of the present global warming focus only on changes during the last 100 years or so, or after 1975 (based on satellite data). By extending records back for 100-200 years (however inaccurate the data may be, compared with satellite data) based on related publications, it has become clear that the present warming research is inadequate. This is because there has been a change of the temperature with an almost constant rate (about +0.5°C/100 years) from about 1800, or even much earlier, to the present. Since the increase began well before the rapid increase of CO2 in about 1940, this warming trend is likely to be a natural change.

One possible cause of the linear increase may be that the Earth is still recovering from the Little Ice Age. World glaciers and sea ice in the Arctic Ocean have been receding since 1800 or earlier; these are not just recent phenomena. It seems to me that most climate researchers are so caught up in the CO2 effect, the Little Ice Age has been all but forgotten.

In addition, multi-decadal oscillations were in a positive phase (~+0.1°C/10 years) during the last 30 years or so of the last century. These trends should be subtracted from the temperature data during the last 100 years.

Thus, there is a possibility that only a fraction of the present warming trend may be attributed to the greenhouse effect resulting from human activities. This conclusion is contrary to the IPCC (2007) Report, which states that “mostâ€? of the present warming (+0.7°C/100 years) is due to the greenhouse effect.

It is urgent that natural changes be correctly identified and removed accurately from the presently ongoing changes in order to find the contribution of the greenhouse effect. Some details are given at: http://www.iarc.uaf.edu/highlights/2007/akasofu_3_07/index.php

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