Demand for food is rising globally. Farming crops are an essential source of food but is also to be blamed for rising carbon dioxide (CO2) in our environment.

Weather experts, the United Nations (UN) and government agencies across the world have blamed industrialization for the increase of CO2 emissions in the atmosphere. However, a team of researchers suggest that increased crop production also contributes to the spike of CO2 levels.

Researchers suggest that increase in farm crops accounts for about 25 percent of the seasonal increase in CO2. Scientists explain that CO2 is absorbed by the plants in the summer and spring when they transform solar energy into food. However, CO2 is also released back to the atmosphere during winter and autumn.

Experts suggest that with increased food demand, food productivity is also estimated to double in the next five decades. Chris Kucharik, from the University of Wisconsin-Madison, who is also the co-author of the study, indicates that the research highlights the influence of human farming on the composition of the Earth's atmosphere.

Kucharik reveals that since 1960s, the production of wheat, maize, soybeans and rice has increased by 240 percent in the Northern Hemisphere. The study also found that Northern China and mid-west U.S. are the regions that have witnessed the biggest spike in farm crop production.

Kucharik explains that crops are not adding CO2 to the atmosphere directly. Crops are like sponge that absorbs and releases CO2. However, the size of the sponge has increased that absorbs and releases higher levels of CO2 as before.

The study suggests that until now, scientists missed the association between CO2 and crops.

"Global climate models don't represent the important details of agroecosystems and their management very well," says Kucharik.

The researchers found that the farming area across the world has not increased. However, the efficiency in crop production has increased a lot in the last few decades, which has affected the atmosphere.

Kucharik suggests that improvements in crop production such as use of fertilizers, plant breeding, improved irrigation, use of technology in farming and more has led to a spike in crop production throughout the world.

The authors of the study also suggest that global warming is also to be blamed for increased crop production in the world. With the Earth getting warmer, the length of the crop growing season has also increased.  

The study has been published in the journal Nature.