While crops designed to produce more have indeed fed the hungry across the world, scientists now suggest that they might also be causing increases in seasonal carbon dioxide shifts.
Plants “breathe” in and out in a particular pattern that causes carbon dioxide to follow a seasonal cycle each year. However, since 1950, it seems that this breathing pattern has significantly deepened. A video released by NASA just a few days ago captures a year’s worth of data in a matter of minutes. It vividly portrays this breathing pattern as carbon dioxide levels increase and decrease across the Northern Hemisphere.
Two independent teams of scientists are convinced they found the reason for this increased swing in CO2 levels. According to their results, farming accounts for anywhere between 20 and 50 percent of carbon dioxide that is taken in by plants in summer and given back during the winter months.
Curiously enough, it’s not because of the tremendous increases in planted acres but because of the spectacular productivity that certain crops have achieved that such swings come to be. Improved breeds, fertilization, irrigation and longer summers have all worked towards the rising levels of carbon dioxide in the atmosphere. Global warming also has a significant role to play in this equation as it has caused summers to stretch out longer.
Although the broader implications of the study’s results are yet to be worked out, one thing is for sure. Man’s influence on the Earth’s ecosystems has been under-appreciated for quite some time. According to Josh Gray, Boston University researcher in its Department of Earth and Environment explains that previous models simulating our planet’s carbon cycle didn’t reveal this human influence that isn’t at all negligible.
US produced corn now yields five times as high as it did before WW2. And although this is news to rejoice about, one can’t fail but wonder whether such increases could have also influenced the Earth’s metabolism, Ning Zeng, Earth Systems Science Interdisciplinary Center at Maryland College Park says.
One study analyzed crop statistics and used carbon-mapping tools to investigate four major crops: corn rice, soy and wheat. According to the results, increased production caused a 25 percent increase in seasonal carbon dioxide swing size and the heavy hitter was corn. It accounted for over 65% of all the increase.
Although corn production has seen a global tripling, its origin lies in relatively small areas in China and the US Midwest.
Researchers believe that these studies prove that farming must be included on the human activity causing seasonal CO2 swings list.