Rising temperatures during the past 25 years have already cut the yield growth rate by 10-20 per cent in several locations.
"We found that as the daily minimum temperature increases, or as nights get hotter, rice yields drop," said Jarrod Welch, lead author of the report and graduate student of economics at the University of California, San Diego.
A decline in rice production will mean more people will slip into poverty and hunger, the researchers said.
"Up to a point, higher day-time temperatures can increase rice yield, but future yield losses caused by higher night-time temperatures will likely outweigh any such gains because temperatures are rising faster at night," said Welch.
"And if day-time temperatures get too high, they too start to restrict rice yields, causing an additional loss in production," he added.
Researchers believe the solutions to these problems are to either create new methods of rice production or develop new rice strains.
The study is published in the online early edition the week of August 9 in Proceedings of the National Academy of Sciences.