Accepting the scientific evidence that the increased carbon-dioxide inatmosphere,introduced mainly by burning fossil fuels since the industrialrevolution,is to cause global warming,the next question is the consequence:is global warming or the alternative global cooling more of a threat to mankind?Global temperature changes are to influence regional precipitationpatterns.Scientific and historical data indicate that at times of global warming,low-latitude lands in continental interior such as China are wetter,whereas high-latitude countries such as Europe are drier.Both sets of circumstanceshave been beneficial to agricultural economy.At times of globalcooling,low-latitude lands in continental interior are more arid,whereashigh-latitude countries are wetter.Both sets of such circumstances are detrimentalto agricultural economy.History also shows epochs of peace and propserity alternating withepochs of war and famines.Those epochs seem to correspond to epochs ofwarmer and colder climate respectively.The two global-cooling epochsduring the last two millennia were the Little Ice Age of the 16th and 17thcentury and the age of the Great Migrations of the late 3rd to the 6th century.In those centuries,there were droughts and famines in China,andbad harvests and popular unrest in Europe.The lesson of history suggeststhat a return of a little ice age would cause such an aridity in China that its1.2 billion population cannot possibly be fed.At the same time,Europeansmay suffer from bad harvest or even starvation.
