text: The answer is as simple as not interfering with the historical and still-ongoing increase in the atmosphere's CO 2 concentration, since this latter phenomenon dramatically increases the water use efficiencies of essentially all agricultural crops -- see Water Use Efficiency (Agricultural Species) in our Subject Index -- thereby enabling farmers to produce ever-increasing quantities of the vast array of grains, fruits and vegetables, as well as animal feed crops, upon which the inhabitants of all nations of the earth ultimately depend for their sustenance, all of which can be accomplished without the need to extract ever greater quantities of ever-more-difficult-to-obtain water from earth's soils.