we have experienced a period of abnormally “good” climate, unusually 
favorable for food production (especially in the United States). This will 
not continue indefinitely. Changes in climate, well within the normal range 
of variation, can be expected to have heavy impact on world food supply. 
NACOA thus addresses first the question of what action we should take 
now, based on what we already know about climate, which could ameliorate 
the impact on food of unfavorable yearly climate variation. But we cannot 
afford to remain content with near-term planning to which we are limited 
if we depend solely on historical evidence. For long-term planning we 
must understand better why and how climate changes on a scale of decades. 
Thus the second issue NACOA addresses in this chapter is what should be 
done to understand better the complicated nature of climate change, what 
influences it, and particularly how it depends on the long-term interaction 
of the oceans and the atmosphere. 
NACOA then turns from the effect of climate on world food to consider 
the effect world energy use may have upon climate. This ranges from 
short-term, small-scale effects known to be occurring today (“hot spots’’), 
to long-range, large-scale, even global effects which might take place within 
the next half century. This concern came about when considering side- 
effects of the intensifying use of fossil and nuclear fuels. Energy cannot 
be destroyed, so except for that very small amount which is stored by 
biological processes, it is either radiated into space or it is embedded in 
the atmosphere and the oceans as heat. The additional heat embedded as 
the result of power-generation and use may, within less than a century, 
be sufficient to impose significant disturbances on climate.* Perhaps we 
can learn enough to foresee what will happen, perhaps enough to forestall 
what is undesirable, soften the effects, or delay them so that we could 
adjust in other ways. We must already begin to deal with local “hot spots.” 
Food: Joseph in Egypt 
World food reserves vary from about 7% to 10% of annual require- 
ments and even small departures from normal productivity can mean mal- 
nutrition and starvation for many. In recent years relatively small climatic 
fluctuations caused the poor crop-growing conditions which led to the 
Russian wheat crop failure in 1972, the temporary disappearance of the 
cold surface waters of the Peruvian Current which contributed to the virtual 
disappearance of Peru’s anchovy fishery and generated a world crisis in 
livestock feed, and the persistent drought in northern Africa which has 
allowed the Sahara Desert to encroach southward causing widespread 
famine and massive population migrations. 
* “Energy Systems,’ by Wolf Haefele, Proceedings of the IIASA Planning Con- 
ference on Energy Systems. International Institute for Applied Systems Analysis, 
Schloss Laxenburg, Austria, July 17—20, 1973. 
