Dating in the 70s
This is because all the processes are interconnected by multiple nonlinear positive and negative feedbacks.The CO2 increment since 1958 has been about 12 ppmv; the climatic effect of man-generated CO2 should therefore be a warming of about 0.07°C. arnumber=5217849 Atmospheric carbon dioxide, which amounts to 320 parts per million (ppm) by volume, rather than being a pollutant, is essentially a thread of life woven through the globe on which we live.
The effect could be negligibly small, or it could be as large as 3 x 10 tons of carbon per yr.It was found that the greenhouse warming of the terrestrial surface can be strongly inhibited by the development of a more isothermal, moister and higher troposphere than at present. CO;2 In no way can the measured increase in CO2 account for the decrease in annual mean temperature of the surface observed since 1940 (Mitchell, 1961). [W]e may conclude that evidence trying to support a continuous global build-up of atmospheric aerosol content due to increased human activities is, to a large extent, inconclusive (Mitchell, 1971). Mitchell (1971) gives an approximate treatment for determining the effect of small changes in aerosol characteristics from an average reference atmosphere on the global climate. CO;2 From the 1880’s till the 1930’s Oslo temperature was more often above the average than below, particularly during the second half of the period which created an upward trend over more than 50 years.He concludes that the presence of stratospheric aerosols would lead to a cooling at the earth’s surface. His analysis does not support the suggestion by other investigators that the apparent worldwide cooling of climate in recent decades is attributable to largescale increases of atmospheric aerosols by human activities. During these years the type Greenland Below (that is, Europe above the mean) was the most frequent one most of the time, and to this was added a large increase of Both Above in the last two decades.Since the 1940’s the temperature at Oslo was more often below than above the long-term average, and during these three decades Greenland Above was the dominant type.It is thus plain that the long-term trends in these regions in winter are closely connected with changes in the frequency of circulation types.