The latest victim of climate change is not the polar bear or melting ice caps - it is food. Food scarcity is an old phenomenon, but a new study warns that warming temperatures could leave more than half the world's population facing food shortages by 2100.
The National Science Foundation study examines the severity of rapidly warming temperatures on the world's food security.
Using direct observation and climate models, the study's authors found there was a 90-percent probability that by 2100 the lowest temperatures during growing season in the tropics and subtropics will be higher than any recorded to date.
The models show the affected areas include stretches from the southern United States to northern Argentina, northern India to southern Australia, and all of Africa. These areas along the equatorial belt are among the poorest in the world and also have the fastest-growing populations.
University of Washington professor David Battisti, who co-authored the report, says the problem could be even more widespread. Citing the deadly heat wave that hit France in 2003, he says the models show those temperatures could become the standard.
"In mid-latitudes, extreme years like 2003 are going to look like the normal 100 years from now at the end of this century," said Battisti. "But in the tropics extreme years in the past, the most extreme years in the past, is still going to be way colder than the years in the future."
The study appears to correspond with a recent U.N. study by the Right to Food program that warned climate change could reduce food production by eight percent between now and 2080.
But Battisti says that figure includes all crops, including plants such as sugar cane, which will perform better in the heat. He says the models show overall reduction of staple crops like rice, wheat and soy could be as high as 20 to 30 percent.
He says to ease the problem carbon dioxide emissions will need to be drastically reduced.
"What we are saying is if you do not stop emitting CO2, and really reduce CO2 emissions seriously, starting almost immediately then this is going to play out," said Battisti. "And it is going to play out to the point where you have already got a billion people already on the edge, who are fundamentally dependent on agriculture for income and food, and that population is going to double, what are the options?"
Battisti says it is unlikely there will be enough investment in development and technology to help the affected countries adapt to the changing agricultural realities.