Can We Grow More Food in 50 Years Than in All of History?

Oct. 5, 2009 — -- How serious is the world's situation? Bad enough, says a leading Australian scientist, that the world will have to produce more food in the next 50 years than we have in the thousands of years since civilization began, and will have a tough time keeping up.

There have been dark predictions --mostly wrong -- of worldwide food shortages before.

But this one comes from Megan Clark, the head of Australia's national science agency, the Commonwealth Scientific and Industrial Research Organisation, or CSIRO. Clark is hardly a wild-eyed extremist; she is a former mining executive.

In a speech in Canberra last week, Clark said growing population will cause exponentially-rising demand, and a warming climate will make the challenge more difficult.

"It is hard for me to comprehend that in the next 50 years we will need to produce as much food as has been consumed over our entire human history," she said.

"That means in the working life of my children, more grain than ever produced since the Egyptians, more fish than eaten to date, more milk than from all the cows that have ever been milked on every frosty morning humankind has ever known."

The so-called green revolution of the last half-century had dramatic results on increasing food production: India alone doubled its wheat harvest from 1965 to 1972, and, as Clark noted, the world overall doubled its food output from 1960 to 2000.

Some parched countries, such as Saudi Arabia, have surprised the world and grown food even in the desert. Lester Brown, president of the Earth Policy Institute and a prominent advocate on world food issues, tells how in the 1970s -- fearful that other countries would retaliate for the 1973 oil embargo with grain embargoes -- the Saudis used their oil-drilling technology to tap deep aquifers. They have used the water to irrigate large swaths of desert.

But Brown says the green revolution has run out of steam. The Saudis admit they are draining those aquifers. The number of chronically-hungry people in the world bottomed out in the 1990s, Brown told ABCNews.com, and is once again rising. Of the 6.8 billion people on earth, he said, more than 1 billion go hungry.

"Most of the things scientists can think of to raise grain yields, they're already done," Brown said. "When you get to the limits of photosynthetic efficiency, there's not much more you can do."