Tess Vigeland: The United Nations says a billion people go hungry on this planet each day. And the overall population is growing. Experts expect we'll top 9 billion by 2045. The looming question: How to feed everyone with limited resources? This week, several major foundations -- including Ford and Gates -- launched a $3 million a year initiative aimed at figuring out how to come up with the food we need.

From the Marketplace Sustainability Desk, Adriene Hill looks at what the answer might involve -- and what it might not.

Adriene Hill: The farmers markets in Los Angeles these days are piled high with organic strawberries and kale. To the contented shoppers, this is what the future should be -- fruits and veggies grown on small farms, nearby the city. But, get over it. This isn't the future -- not if we want to feed everyone.

Pedro Sanchez: If you ask me point blank whether organic-based farming is better than conventional, my answer is no.

That's Columbia University's Pedro Sanchez.

Sanchez: There are just too many of us, we just need too many nutrients.

And those nutrients come from plants that need nutrients that organic fertilizers can't always provide.

Sanchez: It's like a bank account, you've got to have a positive balance.

And if you deposit only organics he says...

Sanchez: You're going to go broke.

One reason experts say organic farming isn't the big-scale answer...

Mark Rosegrant: Organic production tends to have somewhat lower yields compared to non-organics.

Mark Rosegrant is with the International Food Policy Research Institute, an organization focused on sustainable ways to end hunger. He says going all organic would require a whole lot more land. Organic farming is, Rosegrant says, a niche market. It's not bad, per se, but...

Rosegrant: It's not an important part of the overall process to feed 9 billion people.

The Economist recently had a special issue on global food supplies. One piece ended with the thought that the reaction against commercial farming -- with it's dependence on chemicals -- is "a luxury of the rich."

So what does the future of farming look like? Rosegrant thinks that genetically-modified crops have to play a part -- especially as pollution causes the planet warms up.

Rosegrant: I think we do think it's part of the toolbox going forward, that for example to get some of the drought tolerance or other kinds of heat tolerance.

The future may also involve more creative farming.

Organic squash grows in the land between tarmacs at the former El Toro Marine base in Orange County, Calif.

AG Kawamura: We're in the middle of what used to be the El Toro Marine base. We're on an airport actually, and we're farming in the open areas between the tarmac.

AG Kawamura is a third-generation farmer. He also is the former California secretary of Agriculture. The afternoon sun bounces off concrete runways and rows of small organic yellow squash. Kawamura and his brother grow organic and conventional crops.

Kawamura: Globally, the idea, it's going to be a big tent. There's big agriculture, small agriculture, there's room for all.

When you grow lots of food, in lots of ways, in lots of places, Kawamura says, droughts and floods and bugs that chomp down on crops become less of a problem. The future may also involve eating differently.

Mark Bittman: We need to address what diet looks like in the developed world and what diet looks like in the developing world, and how to sort of balance things out.

Mark Bittman is a food columnist for the New York Times and the author of "The Food Matters Cookbook." His mantra -- more veggies, less meat. Animals takes a lot more water and food to grow than plants.

Bittman: We hear a lot about how the Chinese are eating more like us, but the reality is we need to be eating more like the Chinese.

For the billion of underfed people in the world today, there are a billion-and-a-half that are overweight. That too needs to change, Bittman says, as we all start thinking more about what we eat.

I'm Adriene Hill for Marketplace.

Vigeland: When do you buy organic? Adriene asked each of her experts that question. For their answers, and to share yours -- take a look at her blog post.

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