"With Earth's burgeoning populations to feed, we must turn to the sea with new understanding and new technology. We need to farm it as we farm the land," French ocean explorer and television filmmaker Jacques-Yves Cousteau.
By 2030 population growth will increased demand for food by 1 billion metric tons more cereals and a further 120 million hectares of land to be farmed. Yet, the potential for the land to produce more food is almost exhausted. Agriculture already uses almost all of the workable land. Most of the uncultivated land is comprised of deserts, mountains, ice caps, cities, roads, etc.
Meanwhile, almost 70% of the Earth's surface is covered by oceans, from which we get just 2% of our food.
While "farming the seas" may not become a reality in the near feature, We need to start thinking how to develop this with vigour.
We are eating ourselves out of house and home. Recently, Johan Rockström and his colleagues proposed 10 “planetary boundaries” to define safe limits of human activity. Those limits include caps on greenhouse gas emissions, biodiversity loss, the global conversion of land cover to crop land, and other mega-impacts on the earth’s ecosystems. Yet humanity has already exceeded several of them and is on a trajectory to exceed most of the others. The rising demand for food plays a large role in those transgressions.
The green revolution that made grain production soar gave humanity some breathing space, but the continuing rise in population and demand for meat production is exhausting that buffer. The father of the green revolution, Norman Borlaug, who passed away in September at the age of 95, made exactly this point in 1970 when he accepted the Nobel Peace Prize: “There can be no permanent progress in the battle against hunger until the agencies that fight for increased food production and those that fight for population control unite in a common effort.”
That common effort was inconsistent at best and sometimes essentially nonexistent. Since 1970 the population has risen from 3.7 billion to 6.9 billion and continues to increase by around 80 million a year. Food production per person has declined in some big regions, notably sub-Saharan Africa. In India the doubling of population has absorbed almost all of the increase in grain production.
Food production accounts for a third of all greenhouse gas emissions when one tallies those from fossil fuels used in growing, preparing and transporting food; the carbon dioxide released by clearing land for farming and pastures; the methane from rice paddies and ruminant livestock; and the nitrous oxide from fertilizer use.