1. More Productive Land
Economists point out that we keep improving the productivity of each acre of land by applying fertilizer, mechanization, pesticides and irrigation. Further innovation is bound to shift the ceiling upward. Jesse Ausubel at Rockefeller University calculates that the amount of land required to grow a given quantity of food has fallen by 65% over the past 50 years, world-wide.
2. Overestimating Water Demand
Estimates made in the 1960s and 1970s of water demand by the year 2000 proved grossly overestimated: The world used half as much water as experts had projected 30 years before. The reason was greater economy in the use of water by new irrigation techniques. Some countries, such as Israel and Cyprus, have cut water use for irrigation through the use of drip irrigation. Combine these improvements with solar-driven desalination of seawater worldwide and it is highly unlikely that fresh water will limit human population.
3. The Shale Revolution
Until about 10 years ago, it was reasonable to expect that natural gas might run out in a few short decades and oil soon thereafter. If that were to happen, agricultural yields would plummet and the world would be faced with a stark dilemma: Plow up all the remaining rainforest to grow food, or starve. But thanks to the shale revolution, peak oil and gas have been postponed.
4. Alternative Sources
Phosphorus is vital to agricultural fertility. The richest phosphate mines, such as on the island of Nauru in the South Pacific, are all but exhausted. Does that mean the world is running out? No: There are extensive lower grade deposits, and if we get desperate, all the phosphorus atoms put into the ground over past centuries still exist, especially in the mud of estuaries. It’s just a matter of concentrating them again.
5. Greater Affluence and New Technology
In many respects, greater affluence and new technology have led to less human impact on the planet, not more. Richer people with new technologies tend not to collect firewood and bushmeat from natural forests; instead, they use electricity and farmed chicken—both of which need much less land. In 2006, Mr. Ausubel calculated that no country with a GDP per head greater than $4,600 has a falling stock of forest (in density as well as acreage).
Innovation is not under that much stress to keep ahead of resource demand.
Regular agriculture is on track to boost yields to 15 tons per hectare for most of the grains.
Rice breed, DH2525 (Y two superior No 2), produced a harvest of 13.9 tons a hectare during its trial planting in Longhui county in Hunan province.
Does the present breakthrough translate into a yield of 13.5 tons per hectare at commercial scale? Yuan did not think so, but 80% at more than 10.5 tons per hectare is realizable according to past experience.
The highest rice yield in the world is in Australia, on average about 9.9 tons per hectare (660 kg/mu), followed by 6.7 tons per hectare (445 kg/mu) in Japan. The yields of China’s super-rice have now reached 550 and 600 kg/ mu, respectively, at large scale, as the result of the first two phases of development. So spreading best practices boost worldwide yield by 50%-100%. What is done across an entire country (Australia) to other countries.
These plants were generated from regular plant breeding. They did not use genetic engineering. Plant breeding has existed for thousands of years. Assyrians did plant breeding before 870BC.
Milk production was raised by 50% over the last decade and by 5 times over the last several decades. Innovations like washing cows increased milk production. Milk production is still expected to increase by 30% this decade.
Slack in Protein production and ways to improve meat production
It takes about 8 pounds of grain to produce 1 pound of beef. World production of meat is about 260 million tons and beef production is about 55 million tons.
Chicken and fish are about 1.5-2.5 pounds of grain to produce 1 pound of meat.
Greenhouses can boost yield by 6-12 times for regular greenhouses and 20-30 times for “advanced greenhouses”
It is believed the first practical greenhouse was built by French botanist, Jules Charles, in 1599 in Leiden, Holland. Ancient greenhouses might have existed in Pompeii.
Greenhouse management is well understood.
A survey disclosed that construction costs to establish a complete economic unit [greenhouse], to include required equipment, varied from $5,500 by a Louisiana grower, to over $70,000 for a completely automated unit in Canada. Turn key construction costs by competent greenhouse construction contractors were substantially higher than construction costs by an owner/operator who supervised construction and used subcontractors. The average construction costs varied from $1.90 to over $30/ft2 ($20.90-$323/M2). These expenses did not include the cost of land. The average cost was $5 per square foot in the US or Canada.
Penn state has a greenhouse design for Africa that is 5.5 meters by 6 meters (over 300 square feet) and is one-fourth the cost of other greenhouses in Kenya. The Penn State greenhouse costs approximately $600, compared to a standard greenhouse, which goes for about $2,300.
“They can purchase it and pay it off within three growing seasons,” Eckard said. “It’s about empowering others. That’s why I’m involved.” With a greenhouse, a farmer can extend a growing season to three crop cycles and they can keep insects away from the crops.
About $65 million for greenhouses that cover a square kilometer for the average deployed systems.
The lower cost Pennstate system would be about $20 million to cover a square kilometer.
So let us say $65 trillion for 1 million square kilometers. This would be nearly double the agricultural yield. Over years it would be less than 2% of GDP. If volume production and economies of scale could lower the cost the more “advanced greenhouses” were scaled that can achieve 20-30 times the yield of regular land then either the yield could be increased or less land could be used. This is before considering vertical farming to apply skyscraper technology to boost the amount of land. Similar simple approaches can be used to boost water and energy levels