On the importance of the natural components in climate change study: Temperature rise in the study of climate change

The theme of this paper is to show that the temperature rising rate by the greenhouse gases is only 1/5 of what is generally considered. This conclusion is based on identifying two natural global changes. One of them is a near-linear change after the Little Ice Age (LIA) and the second is the Pacific (PDO) and Atlantic AMO) decadal oscillations, together called MDO. After the end of the LIA in about 1850, the rising rate of temperature rise has been approximately linear with the rate + 0.3°C/100 years, while the MDO has been super9 posed on it with an amplitude of 0.2°C (the range = 0.4ºC) and the period of 40-60 years. The combined rise of temperature by the two natural components between 1975 and 2000 (which is considered to be due to CO2 by the IPCC) is 0.47°C; it is comparable with the observed rise of 0.5°C during the same period. Thus, the contribution of the greenhouse gases for the same period is estimated to be at most 0.1°C, not 0.5°C.It is estimated that the temperature rise from 2000 to 2100 will be 0.9°C± 0.2°C (=‘recovery’ from LIA + greenhouse gases + MDO), namely 0.3°C + 0.4°C ± 0.2°C, namely between 0.7°C and 1.1°C, assuming that the present production rate of the greenhouse gases is maintained.