A Commentary on: Deforestation, Climate Change and Sustainable Nutrition Security: A Case Study of India

Abstract

Solar radiation, temperature, and soil moisture availability are the primary determinants of crop productivity, although humidity and windiness also play critical roles. In order to anticipate how greenhouse-forced climatic changes will affect all of these aspects of climate we will need to know more about the distribution of changes in cloudiness, diurnal temperature wave, evaporation and evapotranspiration, precipitation and regional pressure fields — in other words, changes in weather patterns. General circulation models (GCMs) are not yet able to provide such information reliably on the regional scale. What we can say with some assurance, however, is that mean global temperature will rise as radiatively active trace gases continue to accumulate in the atmosphere and problably more so at the high than at the low latitudes. We can also say with some assurance that on the global scale, both evaporation and precipitation will increase. We know that the regional distribution of changes in precipitation is not yet predictable (Schneider and Rosenberg, 1989). Sinha and Swaminathan’s paper conveys the impression that we know more about forthcoming climate changes on the Indian sub-continent than I believe we do.