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TESTIMONY OF DR. SYUN-ICHI AKASOFU BEFORE THE UNITED STATES SENATE COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION SUBCOMMITTEE ON GLOBAL CLIMATE CHANGE AND IMPACTS HEARING ON THE PROJECTED AND PAST EFFECTS OF CLIMATE CHANGE: A FOCUS ON MARINE AND TERRESTRIAL SYSTEMS

Washington, DC
26 April 2006
(Verbal testimony of Syun Akasofu)

Members of the Subcommittee:

Thank you for providing me with the opportunity to testify at this important hearing today.

The most prominent warming in the world had been taking place in the continental Arctic during the last half of the last century, three times more than in the rest of the world. I would like to bring your attention to this most prominent feature.

We have at least two firm scientific indicators that show it is incorrect to conclude that this warming in the continental Arctic is due entirely to the greenhouse effect caused by man.

The first indicator is that the most advanced 14 IPCC global climate models, which include the best scientific knowledge of the greenhouse effect, cannot reproduce the warming of the continental Arctic that occurred during the last half of the last century. This is the so-called “hindcasting” method and is so far the best scientific test of the greenhouse hypothesis.

The scientific methodology consists of three parts. The first is observation (the temperature variations in this case). The second is to hypothesize causes (the CO₂ hypothesis in this case), and the third is to verify the hypothesis on the basis of the best scientific knowledge available and using a supercomputer, if necessary.

If the computed result agrees with the observations, the hypothesis will become a scientific fact. If the computed result disagrees with the observations, the hypothesis should be disapproved.

If one still insists on the validity of the hypothesis, it will be in the category of science fiction, which can ignore science.

If one insists that global climate models are not good enough to test the greenhouse hypothesis, is there any other quantitative proof that the present warming is caused by the greenhouse effect?

If not, the basic scientific methodology is being ignored, and one is no longer talking about science, but science fiction.

There is no problem with the physics of warming by CO₂. The problem is that the greenhouse hypothesis has failed to reproduce the observations. We encounter many hypotheses, which are based on sound physics (good ideas!). But we have to discard them, if they fail the test quantitatively. This is what all scientists do.

The second indicator is that the geographical pattern of the warming in the Arctic has been drastically changing in recent years. The strong continental arctic warming trend is no longer evident during the last two decades. If the warming trend were entirely due to the greenhouse effect, the past geographic pattern of the warming should intensify. That is not the case. Various warming and cooling of similar magnitude has occurred continuously at different locations in the Arctic during the last 100 years and, thus, it is natural to conclude that such trends would continue.

In addition, long-term records of glaciers and sea ice show that they have been receding continuously since 1800, well before the CO₂ release became serious. We have some evidence that the present recession of sea ice in the Arctic Ocean is due partly to the intrusion of warm North Atlantic water, which is caused by the North Atlantic Oscillation, a natural phenomenon. This warm water is flowing along the Siberian coast and is approaching Alaska at the present time.

The Arctic is obviously the best location for this study because the warming and cooling signals are larger there than they are in the rest of the world.

Some of the Q/A:

Senator Vitter: You said that the Arctic is the best place to do global warming research?

S.-I. Akasofu: Yes

Senator Stevens: Can you estimate the warming caused by the intrusion of the warmer North Atlantic Water?

S.-I Akasofu: We have not done it yet.

Senator Lautenberg: We have a house on fire (meaning global warming). We had better put out the fire.

S-I. Akasofu: I am not sure if we have a house on fire. If we want to put it out (without understanding what is going on), we may make much water damage, ruining the furniture.