Can we feed 9 billion people? And at what costs?

This is an information dense video with both good and bad news...

Good food comes from extensive farming, not intensive farming

GM rice, choice between 2 evils?

From TreeHugger;

Chinese government to allow Chinese farmers to get carbon credits when they use their [GM] rice [which reportedly requires less nitrogen fertilizer]. The reasoning is, less nitrogen fertilizer equals less nitrous oxide emissions (a greenhouse gas 300 times more potent than carbon dioxide). Under the Kyoto Treaty, the credits gained from that reduction can then be sold on the global market, bringing extra money to farmers. "Swapping global rice supply to the GM version, the company says, would save the equivalent of 50m tonnes of carbon dioxide each year, and generate £750m in carbon credits for farmers.

Some readers of TreeHugger commented:

seems like switching one evil for another. Which of the two evils worse though?

Chinese farmers have been using natural fertilizers for centuries before the modern fertizers were introduced. A lot of research (see permaculture and other more progressive form of agriculture) points out a simple method of letting mother nature to generate the necessary nutrients. Let micro-organisms active in our earth again! Another great promise would be a large co-production of fish and rice, similar to aquaponics. Build some fish farm near the rice fields and use the water from the fish farm for the rice! Protein and carbo at the same time, why not?

Vertical Farming

The concept of indoor farming is not new, since hothouse production of tomatoes, a wide variety of herbs, and other produce has been in vogue for some time. ...The Vertical Farm must be efficient (cheap to construct and safe to operate). Vertical farms, many stories high, will be situated in the heart of the world's urban centers. If successfully implemented, they offer the promise of urban renewal, sustainable production of a safe and varied food supply (year-round crop production), and the eventual repair of ecosystems that have been sacrificed for horizontal farming.
Advantages of Vertical Farming

Year-round crop production; 1 indoor acre is equivalent to 4-6 outdoor acres or more, depending upon the crop (e.g., strawberries: 1 indoor acre = 30 outdoor acres)

No weather-related crop failures due to droughts, floods, pests

All VF food is grown organically: no herbicides, pesticides, or fertilizers

VF virtually eliminates agricultural runoff by recycling black water

VF returns farmland to nature, restoring ecosystem functions and services

VF greatly reduces the incidence of many infectious diseases that are acquired at the agricultural interface

VF converts black and gray water into potable water by collecting the water of evapotranspiration

VF adds energy back to the grid via methane generation from composting non-edible parts of plants and animals

VF dramatically reduces fossil fuel use (no tractors, plows, shipping.)

VF converts abandoned urban properties into food production centers

VF creates sustainable environments for urban centers

VF creates new employment opportunities

We cannot go to the moon, Mars, or beyond without first learning to farm indoors on earth

VF may prove to be useful for integrating into refugee camps

VF offers the promise of measurable economic improvement for tropical and subtropical LDCs. If this should prove to be the case, then VF may be a catalyst in helping to reduce or even reverse the population growth of LDCs as they adopt urban agriculture as a strategy for sustainable food production.

VF could reduce the incidence of armed conflict over natural resources, such as water and land for agriculture

Another potential design: