The increasing levels of carbon dioxide in the atmosphere, which are responsible for climate change, could have an adverse impact on crops, according to a new study. Increasing global temperatures reduce the moisture levels in the soil, but this reduction is balanced by the heightened fertilization from rising levels of carbon dioxide.
This carbon dioxide is converted into carbohydrates and fuel during photosynthesis. Scientists say that they can estimate how big a plant or tree can grow using these calculations. It was because of these findings that the Intergovernmental Panel on Climate Change (IPCC) concluded in 2001 that global warming might actually increase crop yields.
But a paper published in Science says that "higher temperatures, poor airflow and trapped humidity" in greenhouse environments could harm crops in the long run. "The two things were very roughly thought to counteract each other," said lead researcher Stephen Long, an agriculture expert at the University of Illinois. "If you raise the CO-2 level under fully open conditions, do you see this large fertilization of crop yield? Roughly what we found was that under open air conditions, that increase appears only to be half of what was expected."
The researchers conducted several outdoor experiments on five crops to prove their point. They analyzed soybeans, wheat, rice, maize and sorghum at the levels of carbon dioxide though to prevail 50 to 100 years hence.
When planted outdoors all crops showed significant reduction in growth. Long said that the experiments suggested that in tropical areas global warming might end up harming the crops. "We also simulated that rise in our experiment," he said. "That reduces the yield of soybean by about 20 percent, which is a very large yield decrease, and this has not been taken account in future projections on food supply."
