As is by now familiar, the book was selectively quoted to try to support the idea that Lamb was predicting something vaguely related to an immenent ice age, and/or strong contemporary cooling. On the contrary, he does no such thing.
Its from chapter 17, page 345, section "Forecasts of the natural climate" (the poster didn't give the section name, leaving us to imply that the text quoted below is a complete forecast: of course it isn't).
"The most accepted forecast of the broad tendency of the natural climate so far issued rests on this sort of basis. In 1974 a specially appointed panel of the National Science Foundation produced the analysis of the position summarized here in Table 11 [a table of fluctuations based on lengths of fluctuations of climate in various time intervals from 100,000 years to 100 years is given]. The net outcome is a suggestion that the natural climate IS AT PRESENT COOLING at an average rate of 0.15C per decade. On this analysis, the net cooling rate would be expected to decline to zero by about the year 2015 and be followed by two or three decades of slight warming, the peak rate being about 0.08C per decade around 2030, and thereafter little change before a further decline a century later. The variations considered in this treatment over periods of about 100,200 and 2000 years (or as some writers would have it 250 and 2500 years) are perhaps generally thought to be solar in origin, although some variations of the tidal forces may be involved. Traces of a periodic variation of about 200 years period-length have also been reported in the (global total) volcanic activity; if real these could contribute to the climatic swings and perhaps help in the forecasting problem"
Note that the "at present cooling" is applied to *the natural climate*. It isn't perfectly clear from the quote above, but this section on "the natural climate" is followed by one on human-induced change; and a summary combining the two views. So the trend (0.15 oC/decade) is *not* a description of temperature trends measured in the real world at that time, but a theoretical value derived from cycle-type models. That the climate was cooling was uncontroversial about 5-10 years previously. By 1982 the cooling trend had ended/become unclear (see wcc-1979).
Lamb then goes on to consider perturbations to the natural climate from human influences: almost entirely about CO2 increases raising the global temperature. With caveats, he reports predictions of T increases of between 1-2 oC for 2050-2100 assuming low CO2 increase or 4-9 oC "on the basis of what are thought to be likelier developments." (p357).
He reports that the "general tenor of the conclusions may be summarized as follows:
The conclusing summary of chapter 17 then combines this to say, after various caveats, that:
There is no necessary conflict is diagnoses which identify:
Our present uncertainties about the overlaps between these tendencies
do, however, frustrate forecasting attempts.
Which is to say that although Lamb though that mild cooling was likely to continue (it didn't) he didn't think it was actually predictable; his views on century-scale warming are fairly compatible with the present-day IPCC position.
W M Connolley, 2004/04.
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