A drop in global malnutrition may depend on agricultural productivity and climate change, according to a recent study.

Researchers from Purdue University in Indiana found that global malnutrition could fall 84 percent by the year 2050 as incomes in developing countries grow -- but only if agricultural productivity continues to improve and climate change does not severely damage agriculture.

"The prevalence and severity of global malnutrition could drop significantly by 2050, particularly in the poorest regions of the world," Thomas Hertel, Distinguished Professor of Agricultural Economics, said in a statement. "But if productivity does not grow, global malnutrition will worsen even if incomes increase. Climate change also adds a good deal of uncertainty to these projections."

For the study, researchers developed a combination of economic models to predict how global food security from 2006 to 2050 could be affected by changes in population, income, bioenergy, agricultural productivity and climate. One model captures the main drivers of crop supply and demand and another assesses food security based on caloric consumption.

Based on the results, researchers determined that income growth coupled with projected increases in agricultural productivity could raise more than half a billion people out of extreme hunger by mid-century.

The researchers said growth in income will allow people to increase the amount of food they consume and "upgrade" their diets by adding more meat and processed foods to staples such as crops and starches. The shift toward a diet higher in calories and richer in protein could lift many in hunger-stricken regions such as sub-Saharan Africa, South Asia, China and Mongolia above the malnutrition line.

The volume of food consumed per capita globally could increase by about 31 percent. In developing regions with strong growth in income and population, consumption could rise by about 56 to 75 percent.

Hertel said these projections depend heavily on corresponding increases in agricultural productivity.

"There is a clear link between productivity growth in agriculture and the number of malnourished people," Hertel said. "Boosting productivity tends to lower food prices, and declines in the cost of food in turn can allow for better nutrition. Income growth alone will not be enough to solve the malnutrition problem."

The researchers also cautioned that the impacts of a changing climate on crop yields remain uncertain.

"Up to 2050, there could be some pluses for agriculture," he said. "But in the longer run, adverse temperatures will likely become overwhelming, and rising carbon dioxide concentrations won't help after a certain point. Eventually, you drop off a cliff."

The findings were recently published in the Australian Journal of Agricultural and Resource Economics.