Existing projections on the impact of higher temperature on agricultural production vary. However, there is empirical evidence that higher temperatures, and the resulting higher levels of carbon dioxide in the atmosphere are expected to lower protein levels of crops such as wheat and rice.

A World Bank report stresses that the impact of climate change on food production could be severe, especially given that the benefits of carbon dioxide fertilisation, which is an increase in rate of plant growth due to increasing carbon dioxide concentration in the atmosphere, are still uncertain. The lower nutritional value of foodgrain would have "strong repercussions on food security and are likely to negatively influence economic growth and poverty reduction in the impacted regions", the report, titled "Turn Down the Heat: Climate Extremes, Regional Impacts and the Case for Resilience", has said.

While agricultural productivity of some regions of the country may improve with higher temperature, studies show that the nutritional value of crops decreases, bringing down the nutritional value of the foodgrain being offered to the households under the proposed law.

Projections on the impact of higher temperatures on account of climate change on agricultural produce vary depending on the temperature rise and location. Some areas, particularly arid regions, could experience improved production on account of higher carbon dioxide levels in the atmosphere. However, even as the quantity of the production increases, the nutritional value decreases.

According to studies, while higher temperatures would affect water availability, chances of droughts and flooding, and other elements that affect food production, these cannot be countered by the benefits of increased carbon dioxide, which are still uncertain.

The World Bank report has drawn on extensive studies linking the impact of climate change on nutritional value of the food production, particularly grains. Studies by D Taub, B Miller and H Allen reveal that while the grain mass increases on account of higher atmospheric carbon dioxide (as a result of global warming), the protein concentration of the grains decreases, particularly in wheat, barley, rice and potatoes.

Rice and wheat are key components of the foodgrain on offer under the food security legislation. More recent studies by Pleijel and Uddling on the impact on wheat production confirm this finding. The study found that increased carbon dioxide levels in the atmosphere result in decreasing the nutritional value of wheat harvests.

The report finds that crop production systems will be under increasing pressure to meet growing global demand in the future. Already the 0.8°C warming has shown to have significant impact on crop yield.