How are rising carbon dioxide levels affecting crops? NASA finds out!

Climate change, global warming and its visible haunting effects on Earth have left the entire world stumped.

The accumulation of greenhouse gases and carbon emissions over the years has put a huge question mark planet Earth's future as a habitat for all living things and beings.

2015 saw the leaders of the world unite to fight against the horrifying phenomena that is slowly taking over the planet and take a pledge to reduce their country's respective carbon foorprints.

At the same time, researchers and scientists across the globe are trying their level best to come up with new technology and new ways through which, the dangers of climate change that threaten our planet can be reduced.

US space agency NASA is among those contributing toward this by carrying out studies in order to create awareness regarding these threats.

According to a new study by NASA, elevated carbon dioxide concentrations in the atmosphere may increase water-use efficiency in crops and considerably mitigate yield losses due to climate change.

The findings show some compensation for the adverse impacts of temperature extremes and water scarcity caused by increasing emissions of carbon dioxide and other greenhouse gases.

As per the space agency, higher concentrations of atmospheric carbon dioxide affect crops in two important ways: they boost crop yields by increasing the rate of photosynthesis, which spurs growth, and they reduce the amount of water crops lose through transpiration. Plants transpire through their leaves, which contain tiny pores called stomata that open and collect carbon dioxide molecules for photosynthesis. During that process they release water vapor. As carbon dioxide concentrations increase, the pores don’t open as wide, resulting in lower levels of transpiration by plants and thus increased water-use efficiency.

Global climate impact assessments for crops have focused primarily on the impacts of elevated atmospheric carbon dioxide on yields, said Delphine Deryng, lead author and a climate scientist at NASA’s Goddard Institute for Space Studies (GISS) in New York City. “There has been very little impact assessment analysis that looked at the dual effect on yield and water use and how they play out in different regions of the world, which is critical to anticipating future agricultural water demands,” she said.

NASA further reported that according to the study, the impact of doubled carbon dioxide concentrations on crop water productivity and yield varies regionally. Results show that maize suffers yield losses with doubled carbon dioxide levels, due in large part to the plant’s already greater efficiency at using carbon dioxide for photosynthesis compared with the other crops. Maize yields fall by 15 percent in areas that use irrigation and by 8 percent in areas that rely on rain. Even so, losses would be more severe without the carbon dioxide increase: yields would decrease 21 percent for irrigated maize and 26 percent for rainfed maize.\

The study offers some hope for crops grown in arid, often economically challenged areas, said Cynthia Rosenzweig, a climatologist at GISS. “For example, farmers may switch to crops where their improved photosynthesis and more efficient water use more than offsets losses due to the high temperatures that climate change will bring.”

The researchers say their findings cast a light on agriculture globally and highlight the importance of studying arid and semi-arid cropping systems. “For farmers, water is essential,” Deryng said. “Building on this research will help them and other stakeholders prepare for production in a hotter, drier planet.”

The results of the study were published in the journal Nature Climate Change on April 18.