CO2 'significantly reduces' nutrients in major food crops Skip to main content

CO2 'significantly reduces' nutrients in major food crops

CO2 'significantly reduces' nutrients in major food crops
wheat The nutrient content of major crops like wheat is likely to be reduced by rising temperatures

Related Stories

Rising levels of CO2 around the world will significantly impact the nutrient content of crops according to a new study.

Experiments show levels of zinc, iron and protein are likely to be reduced by up to 10% in wheat and rice by 2050.

The scientists say this could have health implications for billions of people, especially in the developing world.

The report has been published in the journal Nature.

Start Quote

"It is possibly the most significant health threat that has been documented for climate change”
Dr Samuel Myers Harvard School of Public Health
 
Researchers have struggled over the past two decades to design large scale field trials to accurately model the impacts of increased CO2 levels on the nutritional makeup of crops.
Now an international team has put together a global analysis based on experiments in Japan, Australia and the US.

They've grown 41 different varieties of grains and legumes in open fields, with levels of carbon dioxide expected in the middle of this century.

"It is possibly the most significant health threat that has been documented for climate change," said lead author Dr Samuel Myers from the Harvard School of Public Health.

"We found significant reductions in iron, zinc and protein in rice and wheat, and we found significant reductions in iron and zinc in soybeans and field peas as well," he said.

Scale of the impacts

  • CO2 levels of 546-568 parts per million would reduce nutrients in grains and legumes by the following amounts
  • Wheat - zinc 9.3%, iron 5.1% and protein 6.3%
  • Rice - zinc 3.3%, iron 5.2% and protein 7.8%
  • Field Peas - zinc 6.8%, iron 4.1% and protein 2.1%
  • Soybeans - zinc 5.1%, iron 4.1% and protein 4.6%
  • No significant reductions in maize or sorghum
The researchers estimate that these reductions of up to 10% could have major health implications for millions of people around the world. 

Around a third of the global population are already suffering from iron and zinc shortages, leading to some 63 million life years being lost annually as a result.

"We found that close to 2bn people are getting at least 70% of their iron and zinc from these grains and legumes. So reductions in those crops are potentially quite worrisome in terms of increasing those deficiencies," said Dr Myers.

Eating more food to make up for these reductions in nutrients would not be a good solution, he said.

"The problem with that is that if you eat 5-10% more calories every day it would be a matter of months before we were morbidly obese and bumping into issues around metabolic diseases."
rice  
Varieties of rice reacted differently to CO2, giving hope that new breeds can be developed that don't lose their nutrition
 
The scientists are unsure of the mechanism through which levels of carbon dioxide of around 550 parts per million limit crop nutrition.

It had been thought that crops would substitute carbohydrates for nutrients as the gas increased. But the new research was inconsistent on this point.

Breeding difficulties
 
The authors did find that within some species such as rice, there are considerable differences in response to CO2 which gives them hope to overcome these reductions.

"What we speculate is that this could produce a basis for breeding programmes to produce rice that was less sensitive to CO2. We are not proving that this is possible but we are just saying there may be a genetic basis for doing it," said Dr Myers.

"These breeding programmes all sound good on paper but you can produce a cultivar and the yield is reduced or it just doesn't taste good. It's complicated."

The impact of carbon on nutrient levels is another blow to global food production.
According to the Intergovernmental Panel on Climate Change (IPCC), crop yields are also set to suffer as a result of rising temperatures.

Their recent summary on the impacts of global warming stated that the production of maize, wheat and rice will go down over the course of this century.

http://www.bbc.com/news/science-environment-27308720

Comments

Popular posts from this blog

Chronology of the Press in Burma

1836 – 1846 * During this period the first English-language newspaper was launched under British-ruled Tenasserim, southern  Burma . The first ethnic Karen-language and Burmese-language newspapers also appear in this period.     March 3, 1836 —The first English-language newspaper,  The Maulmain Chronicle , appears in the city of Moulmein in British-ruled Tenasserim. The paper, first published by a British official named E.A. Blundell, continued up until the 1950s. September 1842 —Tavoy’s  Hsa-tu-gaw  (the  Morning Star ), a monthly publication in the Karen-language of  Sgaw ,  is established by the Baptist mission. It is the first ethnic language newspaper. Circulation reached about three hundred until its publication ceased in 1849. January 1843 —The Baptist mission publishes a monthly newspaper, the Christian  Dhamma  Thadinsa  (the  Religious Herald ), in Moulmein. Supposedly the first Burmese-language newspaper, it continued up until the first year of the second Angl

ARSA claims ambush on Myanmar security forces

Arakan Rohingya Salvation Army (ARSA) on Sunday claimed responsibility for an ambush on Myanmar security forces that left several wounded in northern Rakhine state, the first attack in weeks in a region gutted by violence. Rakhine was plunged into turmoil last August, when a series of ARSA raids prompted a military backlash so brutal the UN says it likely amounts to ethnic cleansing of the Muslim Rohingya minority. The army campaign sent some 650,000 Rohingya fleeing for Bangladesh, where refugees have given harrowing accounts of rape, murder and arson at the hands of security forces and vigilantes. Myanmar's military, which tightly controls information about Rakhine, denies any abuses and insists the crackdown was a proportionate response to crush the "terrorist" threat. ARSA have launched few attacks in recent months.  But the army reported that "about ten" Rohingya terrorists ambushed a car with hand-made mines and gunfire on Friday morning

Thai penis whitening trend raises eyebrows

Image copyright LELUXHOSPITAL Image caption Authorities warn the procedure could be quite painful A supposed trend of penis whitening has captivated Thailand in recent days and left it asking if the country's beauty industry is taking things too far. Skin whitening is nothing new in many Asian countries, where darker skin is often associated with outdoor labour, therefore, being poorer. But even so, when a clip of a clinic's latest intriguing procedure was posted online, it quickly went viral. Thailand's health ministry has since issued a warning over the procedure. The BBC Thai service spoke to one patient who had undergone the treatment, who told them: "I wanted to feel more confident in my swimming briefs". The 30-year-old said his first session of several was two months ago, and he had since seen a definite change in the shade. 'What for?' The original Facebook post from the clinic offering the treatment, which uses lasers to break do