The heat is on and will take a heavy toll on your rice bowl in the coming years. The reason: global warming.

Global warming, which will increase the temperatures up to 4.5 degree celsius by the end of the century, will hit rice cultivation hard by reducing production by 7 to 60 per cent this century.

In fact, the scientific world views the threat of increasingly high temperatures to rice - now the principal crop for the country's food security with 44.6 million hectare area and 89 million tonnes in production - as a huge problem. According to scientists, temperature is a major determinant of crop development and growth of rice. Rice yields would dip 10 per cent for every 1 degree Celsius increase in minimum temperature during the growing season.

The scene will be alarming if you take into consideration the population growth. The country's rice production has to be enhanced to 122 million tonnes by 2020 to meet the increasing demand.

Almost 90 per cent of the world's rice is produced and consumed in tropical Asia, and this factor alone is likely to force agri-research into rice varieties that are highly temperature tolerant.

Scientific studies presented at the International Rice Research Conference in October 2006 have said that the results of climate change impact assessment show general rice yields being seriously affected not just in north-west India but countrywide. 

While in the short term rice production may not be affected significantly, but in the long term climate change will have significant adverse impact on India's rice production.

A study by Indian Agricultural Research Institute scientists pegged the range of yield reduction from the technological determined level from 7 per cent in 2020 to a significant 25 per cent in 2080.

The study used models with future climatic anomalies as inputs into the crop sensitivity model for five stations, based on district-level historical rice yield and monthly rainfall as well as the maximum temperatures and minimum temperatures for the past 30 years.