Image Source: Flickr. By: KevinLallier.

You’ve probably heard all the reports about how Climate Change will damage our crops and livelihoods via drought, flooding (from rising sea levels), and so forth. However, I’ll bet you haven’t heard about the latest threat climate change poses to crops: decreased nutritional value.

A study, published in Science magazine, shows that increased levels of CO2 in the atmosphere could reduce crop protein by 20%. Scientists tested the 2 main types of soil nitrogen available to plants (nitrate and ammonium) and the affect they had on 2 major types of plants (monocotyledons and dicotyledons) that were exposed to an atmosphere with high levels of CO2. The study showed that plants exposed to nitrate had difficulty producing nitrogen-containing compounds (protein, for example) but the ammonium-exposed plants did not.

Study author, Arnold Bloom, explained that the problem is “most crop plants…use nitrate as their main form of nitrogen”. He added that:

“Wheat grain that has been exposed to the conditions that we expect in the next few decades declines about 20%.”

Although plants may eventually adjust to the rising levels of CO2, this study suggests that the reason why the plants might not do as well in CO2-rich environments as expected can be linked to the nitrate (or lack thereof). Wheat physiologist, Marta Lopes, stated:

“This study is alerting us about the need to develop new fertilization techniques and to improve crops’ nitrogen use efficiencies.”

You can read the full study here.