Imagine the devastation that would have occurred had agricultural technology been frozen at 1961 levels, while mortality rates continued to drop, pushing up population. Massive deforestation, soil erosion, greenhouse gas emissions, and losses of biodiversity would occur with the more-than-doubling of land and water diverted to agriculture, but hunger and starvation would not decline. The additional pressure on the land would have increased land prices, making it more difficult to reserve land for conservation (except, possibly, in the deserts, the frozen polar regions, and the peaks of mountain ranges).
Such tragic results did not happen, thanks to improvements in productivity at each step of the food and agricultural system. To begin with, science-based varieties of seeds helped increase global yields for all cereals, the grains that are grown on 45 percent of the world's cropland. Cereal yields went up by 126 percent between 1961 and 1998 (FAO 2001). To more fully exploit these high-yielding crop varieties, farmers implemented a set of complementary technologies. Yes, these caused environmental problems. Yet they also increased productivity, reducing the amount of land devoted to agriculture.
Other factors also contributed to farm productivity. These include (a) innovations in animal husbandry, (b) technologies for storage, handling and processing (e.g., plastic bags, refrigeration, canning and preservation), and (c) a wider - largely fossil fuel driven - global infrastructure for the efficient transportation, storage, distribution and trade of agricultural inputs and outputs (which also helped reduce wastage and spoilage) (Goklany and Sprague 1991).
Recognizing the benefits of these technologies does not mean that we should ignore the tendency to overuse inputs such as water, fertilizers, pesticides and energy, in part because of subsidies and, in the case of water, lack of property rights. So although total benefits of various technologies probably exceed total costs, marginal costs may not always exceed marginal benefits.
To put a long-term focus on the environmental pros and cons of agricultural technologies, many effects of agricultural pollutants seem reversible, although not always rapidly and sometimes at substantial cost. In the richer nations, new laws and large investments in new and clean technologies have helped many freshwater systems and aquatic and avian species recover from decades, if not generations, of abuse (Goklany 1996).
Soil erosion has declined; the Rhine, Thames, and Hudson Rivers are cleaner - and support more species - now than in past decades; and DDT and other pesticide residues in freshwater fish and human adipose tissue have dropped by an order of magnitude or more in North America and Europe. Thus, the direct effects of agricultural pollutants seem no more long-lived or irreversible than the indirect ecological and biodiversity effects of additional land clearance that would have occurred without those technologies.
Some have argued that agricultural technology, by making more food available, merely postponed the Malthusian day of reckoning, leading to a larger population which, in turn, increased net conversion of wildlife habitat. In response to this claim, I would first argue that agricultural technology, by reducing starvation and hunger, helped reduce maternal and infant mortality rates. Not only has this reduced misery worldwide, but it has also directly improved human well-being.
Second, failure to produce enough food would not necessarily have led to protection of habitat for the rest of nature. Consider the statistics about India. In 1961, daily food supplies per capita in India were 2,073 Calories (2,073 kilocalories, more accurately). At that time, 398 million acres of India's total land area of 734 million acres (or 54 percent) was devoted to crop production.
Between 1961 and 1998, population increased by 117 percent, food supplies per capita grew 19 percent, and India became, at least temporarily, a net grain exporter. Yet cropland increased by only 5 percent (to 420 million acres). Forest and woodland area expanded 21 percent between 1961 and 1994 (from 141 to 170 million acres) (FAO 2001).
Assuming no improvement in agricultural production since 1961 or any change in the 1998 population level, available daily food supplies per capita would have slid to 955 Calories - well below even the minimum energy an adult needs to keep basic metabolic activities functioning at rest in a supine position! The Food and Agricultural Organization (1996) estimates that minimal level of existence as requiring 1,300 to 1,700 Calories/day. Mass starvation and death would have been inevitable.
Would that have translated into more wildlife habitat? Not likely. Faced with such hunger, it seems unlikely that India's population and policy makers would have been more willing to set land aside for conservation. India would have been fortunate not to have lost much of its remaining forests, let alone "reserve" as much as the 35 million acres currently in partially or fully protected areas (World Resources Institute 2000).
By reducing hunger, agricultural technology has not only improved human welfare and reduced habitat loss but has made it easier to view the rest of nature as a source of wonder and not merely as one's next meal or the fire to cook it with. It also decreased the socioeconomic cost of conservation.
These factors helped create the conditions necessary for support of conservation within the body politic. Finally, in the absence of technological progress, would the World Conservation Union's Red List, which classifies about a quarter of all mammalian species as threatened (World Conservation Union 2000), been larger, because more species would be threatened - or smaller, because more species were extinct?
