How much Land Can Ten Billion People Spare for Nature in an Uncertain Climate

The Second Kuehnast Lecture, 1994

Paul E Waggoner

The Connecticut Agricultural Experiment Station, New Haven

Making food for an exploding population a function of cropland taken from Nature and yields falling with changing climate produces a ‘dumb farmer’ scenario of doom.  A doomed, hungry humanity will not spare nature reserves.  While all people temper their own multiplication and also greenhouse gas emissions, smart farmers have a peculiar responsibility to improve the yield coefficient of land per crop connecting cropland to food.  They face the big question, “For a warmer planet with more people, more trade and more CO­2 in the air, can farmers prepare within a few decades to sustain more production while emitting less and stashing away more greenhouse gases?”  Because warmer inevitably means faster evaporation, water seems the crucial factor.  Still the adaptability of farmers proven by history, their past conservation of cropland by raising yields, the security of trading with nations where climate favors farming, and slower evaporation when CO­2 narrows stomata lend hope for meeting the challenge of the big question. Since the crux of climate change is uncertainty, a prudent nation will hedge for the risks by assembling a diverse portfolio of agricultural assets and assure their flexibility.  The asset of land brings diverse climates.  The asset of trade allows exchange among the climates. Institutions become assets if they encourage changing rather than static land and water use.  Finally, exemplified by agricultural meteorology, research is the gilt-edge asset for adaptation.  Meteorology can model future and measure actual climates.  And especially, its timely forecasts mitigate the harm and heighten the benefit of climate change in a smart farmer scenario.