Japan Institute for National Fundamentals

　　　　　Many people may wonder if summer heat waves this year, floods accompanying typhoons and other abnormal climatic or environmental changes might have resulted from global warming by greenhouse gas emissions through human economic activities, being concerned about the future of the earth.
　　　　　Then, I would like you to first know that almost no global temperature rise has been seen since around 2000 while greenhouse gas emissions including carbon dioxide emitted through coal and oil combustion have still continued to increase.

Minimal temperature rise in the past two decades
　　　　　The Paris Agreement, an international framework of global warming countermeasures agreed on in 2015, seeks to hold down a global average temperature rise from pre-industrial times through 2100 to less than 2°C. According to 102 computations by a group of scientists using 32 models, the average global temperature is projected to increase by 0.3-1.2°C in about two decades from 2000. In fact, however, the average temperature increase from 2000 has been limited to only 0.1-0.2°C. The projection using supercomputers proved wrong. This fact is not known by ordinary citizens as it has not been reported publicly.
　　　　　Why has the computer projection been wrong? Because the International Panel on Climate Change has concluded it is highly likely that the global temperature increase in the second half of the 20th century is attributable to GHG emissions. The supercomputer projection only represents an extension of the temperature rise in the second half of the 20th century until 2100. Initial data for computation had been wrong.
　　　　　Why has the IPCC reached such conclusion? Because the IPCC has ignored natural fluctuations. The earth has repeated large-scale warming and cooling through natural fluctuations. As a matter of course, natural fluctuations have been going on. Regrettably, there are no means to revise such fluctuations. In my book titled “Tadashiku shiru chikyu ondanka (Understanding global warming correctly)” (published by Seibundo Shinkosha in 2008), I attributed five-sixths of the temperature rise in the second half of the 20th century to natural fluctuations and less than one-sixth to GHG emissions. Given a temperature change since 1800, I predicted that the average global temperature would remain unchanged for some 30 years from 2000.

Has climate change occurred?
　　　　　Some researchers in the U.S. academic world have at last begun to admit natural fluctuations and revise global warming projections. Global warming has been alleged to accelerate climatic changes. For example, however, I question if the annual number of typhoons seen in the vicinity of Japan increased in the past half century. The U.S. National Oceanic and Atmospheric Administration says that the number of tornadoes in the U. S. has decreased. Tornado damage has increased year by year due to progress in urbanization. In the past, any tornado might have passed through large farms or wilderness.
　　　　　Television reports on global warming frequently show ice collapsing from a glacier. However, it is natural for the edge of a glacier to collapse because a glacier is an ice river. I have no objection to cutting GHG emissions. However, scholars and ordinary citizens know too little about global warming. Computer experts have no interest in the long history of changes on the earth. I believe that it is impossible to accurately project climate change without sufficiently understanding natural fluctuations.

Syun-Ichi Akasofu is a visiting fellow of the Japan Institute for National Fundamentals and Professor Emeritus at the University of Alaska.