The report by Oxfam released Tuesday said the demand for food will grow 70 to 90 percent by 2030, without factoring in the impact of climate change.
Increasingly frequent droughts, floods and changes in agricultural patterns from global warming will add pressure to what the agency calls an already broken system.
"The food system is buckling under intense pressure from climate change, ecological degradation, population growth, rising energy prices, rising demand for meat and dairy products and competition for land for biofuels, industry and urbanization," Oxfam said in its report, "Growing a Better Future."
It said 925 million people - one out of seven - are hungry, and the figure is likely to surpass 1 billion by the end of this year.
"If you think we have a crisis here, in 30 years it will be a cataclysm if the status quo remains," said Gonzalo Fanjul, a policy adviser for Oxfam.
The U.N. Food and Agriculture Organization says food prices are higher than they have been in the last 20 years, surpassing the 2008 price spike that set off food riots in cities around the world. Instability fueled by high oil prices is likely to continue, the Rome-based FAO said.
"Prices will never come back to the levels of the 90s, but there will be ups and downs," said Fanjul.
Oxfam's report assigned part of the blame to commodities traders, saying three companies control 90 percent of the trade in grain. It urged greater regulation of speculation in the international food market.
But the system that controls global food production and requires reform is far broader, it said. It includes large-scale landowners in poor countries, farm lobbies and seed manufacturers in wealthy countries and high-carbon industries blocking action on climate change.
"For too long governments have put the interests of big business and powerful elites above the interests of the 7 billion of us who produce and consume food," Oxfam's executive director Jeremy Hobbs said in a statement.
The report called for building a multilateral system of food reserves, ending biofuel subsidies so more crops go toward edibles, and more investment in the 500 million small farms in developing countries that support 2 billion people.
The long-term problem is that the growing number of people on Earth and their increasing demand for an animal-based, Western-style diet is outstripping the growth in agriculture. Oxfam said global crop yields grew an average 2 percent between 1970 and 1990, but then dropped to 1 percent and are still declining.
"The dramatic achievements of the last century are running out of steam," it said.
--- AP writer Alessandra Rizzo in Rome contributed to this article. (Copyright 2011 by The Associated Press. All Rights Reserved.)