Limitations of Substitutes


When limited using one substance, we may turn to a substitute which may not serve our purpose less well and introduce new problems besides. An example is R134a refrigerant instead of R12 Freon, the king of ozone depleting chemicals (ozone hole). But R134a is less efficient as a refrigerant, so it requires slightly more energy to use; plus it’s a potent greenhouse gas, so sealing leaks is no less important.

Topsoil illustrates this point differently. We’ve run ahead of natural replenishment losing topsoil for centuries; not a new risk, but getting worse. Fertilizer substitutes for nutrients in soil lost to prior crops, run-off, and evaporation. Crop yields are boosted by hybrid varieties and nitrate fertilizer synthesized from natural gas. So we use fuel to fertilize fields as well as work them. That’s the essence of industrial farming.

We need topsoil for food, but when we consider food shortages, we jump on how to grow more – expansion of industrial farming. There are other avenues to resolving “world hunger.” One is to keep food from spoiling or being thrown away. Estimates of the eaten-to-grown ratio are as low as 50% for various reasons: field rot, pests, spoilage in storage, or dumped as garbage.

Food is one item where drastic reduction in end consumption is not desired, but we can dramatically reduce resource waste all along the human supply chains used to provide it.