Carbon dioxide is fuel that helps the plants humans require for food to grow, but researchers are learning that too much of it actually hurts the nutritional quality of rice, wheat and other crops so much of the planet depends on.
Rising carbon dioxide levels in the atmosphere are going to have profound implications for the future of agriculture and public health, epidemiologist Kristie Ebi told a Thursday audience at the TED Talks in Vancouver.
Field studies have revealed that rice crops grown in conditions with carbon dioxide levels expected mid-century have 10 per cent less protein, 15 per cent fewer B1 and B2 vitamins, and 30 per cent less folate, Ebi said.
“These are very serious potential consequences for health as carbon dioxide continues to rise,” Ebi said.
Those B vitamins are important in physiological functions of the body and folate critical for pregnant mothers and child development.
For wealthier people, who can afford to compensate for the faltering nutrition of plants, the trend isn’t that big a deal, Ebi said.
“When you start thinking about the poor in every country who rely on starch, this will put people on the edge over the edge and into deficiencies that create all sorts of health problems,” she said.
Ebi, who is the Rohm & Haas professor in public health at the University of Washington, added the impact will move up the food chain as the forage crops for livestock also declines in nutritional value.
“This is true in Vancouver, the state of Washington and everywhere else,” Ebi said in an interview following her talk.
And she is just looking at the effects of rising CO2 on plant nutrition, never mind the impacts of climate change — extremes of flooding, temperature and drought — that will also alter agriculture.
TED is an acronym that stands for technology entertainment and design and the idea of TED Talks is to expose ideas deemed worth spreading. Ebi was keen to make sure this science becomes more widely known.
To date, although studies are being published, Ebi said it isn’t on the radar of government agencies.
“I came here primarily to raise awareness,” Ebi said of her TED talk. “This is an issue people should know about, should be paying attention to.
“And many of the people who come to TED invest in companies, invest in new technologies and invest in lots of different ways.”
So the talk was also a nudge to get people thinking about making investments in the additional research needed for a more complete understanding of the phenomenon.
For instance, the studies that have been done project the potential for nutritional decline into the future.
Ebi said what researchers don’t know is how much the nutrition in food has already declined as CO2 has risen in the atmosphere since the start of the Industrial Revolution.
Reducing greenhouse gas emissions is the ultimate solution, Ebi said, but it will take decades for even dramatic reductions to make a difference.
“The lifetime of carbon dioxide in the atmosphere is about 1,000 years,” Ebi said. “So, yes we need to reduce our emissions and yes, (the modelling) shows that the most effective route is to reduce our emissions (but) that’s not enough.”