This 2013 report from the Asian Development Bank has some eye-popping statistics.

Trends in population, economic growth, industrialization, urbanization, and changing dietary patterns have largely encumbered already scarce natural resources. Total arable land per person in East and South Asia has been shrinking, falling from almost one-quarter hectare per person 50 years ago to an estimated one-tenth hectare by 2050. Water resources are also strained. Across Asia, between 60% and 90% of water is used for agriculture. However, share of household and industrial water consumption almost doubled during 1992–2002. The region would need an additional 2.4 billion cubic meters of water each day to provide each consumer with 1,800 calories per day by 2050. The growth in yields has been declining in Asia. And the projected impact of climate change will significantly affect soil and water resources in many subregions.

Expanding cultivated lands is no longer an option for food production growth in nearly all countries in Asia and the Pacifi c. Although most arable land is accounted for, there remains considerable room to increase crop yields even with currently available resources and existing technologies—provided appropriate market incentives and public support mechanisms are in place. Agricultural output and productivity can be raised in two broad ways: (i) through improved productivity at the farm level, and (ii) through better postharvest productivity. In South and Southeast Asia, about one-third of food production is lost as it travels through the supply chain.

During my brief time living in Asia and working on urban development and water resources projects, I started to have a sense that the sheer scale of human activity in Asia is such that it will determine our civilization’s future. What we do here in the United States or the western hemisphere more generally is less consequential, simply because we don’t have the scale of population, agricultural and industrial production, consumption, and more importantly, exponential growth of all these things that Asia is experiencing.

I am not an expert on agriculture, so it is easy for me to sit here and opine on organic farming and sustainable agriculture. Feeding people by the billions is a serious business where any missteps have unacceptable consequences, and so far a combination of irrigation, fossil-fuel derived fertilizer, massive surface water diversion and groundwater mining has largely managed to do that, although the poor sometimes get left behind. In the short term I don’t think we want to disrupt this system. But we better give some serious thought to whether it is sustainable (in the dictionary sense) in the face of exponential population and consumption growth. If not, the scale of human misery that will result could be truly awful.

So I would look for incremental improvements to farming practices that increase sustainability and reduce long-term risk without decreasing output. Soil and water conservation seem like a good place to start to me. If your farming practices are building the amount and fertility of the soil from year to year without causing water scarcity or pollution, that is a good clue that you may be doing something sustainable.