The entire premise of this article became suspect in the first paragraph.

Hunger today (the 1 billion people who do not get enough to eat worldwide) is not caused by an inability to produce food. In fact, by most estimates, we ALREADY produce enough food worldwide for 9 billion people.

Rather, the problem is one of poverty, corruption, war, food distribution that favors profit over people, land usage inequities, U.S. ag subsidies that skew the international commodity markets, and the use of expensive and unsustainable agricultural inputs like GMO seeds and fossil-fuel derived poisons and fertilizers, etc.

Even in the U.S. where food is cheap and plentiful, 1 in 10 are threatened with hunger and food insecurity. Agricultural science has little to offer this political problem.

But part of solving hunger and climate change means we need to create local food security and self-reliance worldwide, which means de-industrializing agriculture and boosting the agricultural knowledge of people worldwide, as mentioned in the article.

Even the IAASTD recognizes that organic agriculture, permaculture and agroecology practices (like holistic management, polycultural guilds, push-pull, seed selection and microclimate breeding) used on smallholdings produce better yields and better human nutrition for less money--while building topsoil and restoring biodiversity--than any industrialized farming technology is capable of, especially in developing countries.

In sum, hunger today and tomorrow is mostly a political problem, not a scientific one. WE ALREADY HAVE THE TECHNOLOGY to feed the world sustainably. But the governments and corporations who profit from hunger would have to give up a lot to have the will to use it on a global scale.

Fortunately, many people are working at a community level developing and disseminating bioregionally-appropriate agroecological and permaculture best practices and fostering local self-reliance. This is how real change happens anyway.

Dawn Gifford makes a valid observation. I believe the first step is to spend 'Stimulus Money' to create sustainable jobs for the unemployed to clean and recycle environmental waste to provide a plentiful and permanent source of clean fresh water.

Many years ago while taking tests I noticed that when more than4 qualifications were involved in making a statement or exspressing an idea it was most often wrong or incorrect. The authors list 7 variables and state more exist. As the number of conditions= variables increase the chance of fullfulment decreases exponentually.
Dawn Gifford in her coment plugs "equetable land distribution".
In this she agrees with Bishop Zimmeri who 2007 was head of the Catholic bishops conference in Guatemala. Guatemala has 27 Million Acres of which 6 million are either row crop or tree crop land. It also has 14 Million people. Equal distribution will give people less than 1/2 acre. The population at present rates will double in less than 30 years.
Personally I give as much as I can to an organization that does family planning in Guatemala. The editors would probably object to a direct named plug. If you are interested please contact me at my EMAil. Ben Franklin said" Better done is better than better said" If I was young rather than old I would start an organization called "DO". to do.

Peter Hubbell
P.s. Haiti: Even with the horrible losses the population will increase at least 100,000. To add to the 850Per Square mile.
P.P.S. Mongabay frog teee-shirt is potentually deadly as some fool will try handling or worse sucking a poison arrow and die.

GMOs are not sustainable according to the true definition of the word. Monsanto has been touting their 'sustainable agriculture' for years and they rely on high inputs of fertilizers and pesticides, exploitative user agreements, and teams of lawyers to enforce their power over food production. Agroecology is a science based on sustainability, not genetically engineered seeds. GE seeds are absolutely not the way to 'feed the world'. That is simply a bogus, self serving argument that the agribusiness industry unashamedly promotes. GMOs were unleashed on this Earth twenty years ago, and they have done absolutely nothing to alleviate world hunger. In fact, no one can argue against the fact that world hunger has increased tremendously since GMOs were made available to farmers. All these companies do is trap farmers in a chemical treadmill that furthers their dependence and has harmful effects on the environment.

And following the argument that we have to provide more food in the future- hasn't anyone thought of what challenges we will face after 2050? After we already have 9 billion people on the planet? Continuous growth is not a good thing, and the last thing we should be doing is planning for it! How about promoting contraceptives for a change instead of trying to find another technological 'fix-it'?

Corporations have embraced the term sustainability in their greenwashing campaigns and it has lost it's true meaning. At this point, the word 'sustainable' means less than nothing at this point, so please stop using it. This new study in Science is just another ecologically blind assertion by scientists who rejoice in the imaginary possibilities of biotechnology.

Monsanto is basically about creating a monopoly. It is now being investigated by U.S. government re monopolistic practices. Their idea of seeds that will grow with less water will lead to dust bowls. How-- you go in and plow up low rainfall grasslands and plant-- if rains are "normal" you get a crop, but every few years rains fail as these areas are areas of high declination from average rainfall. Think Sahal or N.E. Brazil. No rain + wind= dust as ground has no vegatation to hold soil.
Re fertilizer. Many soils have been degraded of fertility useing purely organic farming as when to take off and eat crops or livestock you are taking chemical elements= fertility. No type of farming can create them. Liming on acid soils by changing Ph can make them more available as both high and low Ph tends to tie them up in non sololable forms. Here in Arizona desert you don't want to acidify as this would release Cadmium which at high levels and is poisonous.

I think it is exceedingly unlikely that the world will reach 9 billion. There are far too many collapsing systems within the biosphere today for this figure to ever be realized. We are almost at peak population world wide now.

By 2050, we will have seen several huge events. The severity of climate change will have been fully realized by humans, impacting global populations everywhere and agricultural production. The severity of depleted aquifers, soils and minimal agricultural outputs will prevent such human numbers ever being realized.

I fully expect energy wars to have earnestly commenced within the next decade too, far sooner then 2050, and this will lead to WWIII, new disease and plague outbreaks, and the continued expansion / exploitation for energy with resultant pollution and ecosystem destruction.

I suspect these scientist are simply dreaming, creating a wish list of 'possibilities' not rooted in reality. Human nature being what it is, we will never see 9 billion on this planet (thankfully).

These kind of numbers stagger the mind, the destruction required to the biosphere would make this considerably worse then it already is.

There is an alternative and highly detailed set of modelling reports out - commissioned by CIWF and Friends of the Earth from the Potsdam Institute which show that we can feed this enlarged populatin without trashing the planet or investing in unethical or untested technologies and practices - - it is an extremely detailed peice of modelling and well worth a look - see

http://www.foe.co.uk/resource/reports/eating_planet_report.pdf

My presure to see great potential to save the future from diffrent persons ;i appriciates the article and the thought in it is fully implemented.
Never the less I do suggest reduction on population growth rate to zero population growth rate inorder to create sustainable resources to ensure food production.
Those resources include Land,Water,capital,climate and others all these will be dirrectly be affect food production and should population increase they size decreases .