Rising CO2 poses significant threat to human nutrition

first_imgAt the elevated levels of atmospheric CO2 anticipated by around 2050, crops that provide a large share of the global population with most of their dietary zinc and iron will have significantly reduced concentrations of those nutrients, according to a new study led by Harvard School of Public Health (HSPH). Given that an estimated 2 billion people suffer from zinc and iron deficiencies, resulting in a loss of 63 million life years annually from malnutrition, the reduction in these nutrients represents the most significant health threat ever shown to be associated with climate change.“This study is the first to resolve the question of whether rising CO2 concentrations — which have been increasing steadily since the Industrial Revolution — threaten human nutrition,” said Samuel Myers, research scientist in the Department of Environmental Health at HSPH and the study’s lead author.The study appears online May 7 in Nature.Some previous studies of crops grown in greenhouses and chambers at elevated CO2 had found nutrient reductions, but those studies were criticized for using artificial growing conditions. Experiments using free air carbon dioxide enrichment (FACE) technology became the gold standard as FACE allowed plants to be grown in open fields at elevated levels of CO2, but those prior studies had small sample sizes and have been inconclusive.The researchers analyzed data involving 41 cultivars (genotypes) of grains and legumes from the C3 and C4 functional groups (plants that use C3 and C4 carbon fixation) from seven different FACE locations in Japan, Australia, and the United States. The level of CO2 across all seven sites was in the range of 546 to 586 parts per million (ppm). The researchers tested the nutrient concentrations of the edible portions of wheat and rice (C3 grains), maize and sorghum (C4 grains), and soybeans and field peas (C3 legumes).The results showed a significant decrease in the concentrations of zinc, iron, and protein in C3 grains. For example, zinc, iron, and protein concentrations in wheat grains grown at the FACE sites were reduced by 9.3 percent, 5.1 percent, and 6.3 percent, respectively, compared with wheat grown at ambient CO2. Zinc and iron were also significantly reduced in legumes; protein was not.The finding that C3 grains and legumes lost iron and zinc at elevated CO2 is significant. Myers and his colleagues estimate that 2 billion–3 billion people around the world receive 70 percent or more of their dietary zinc and/or iron from C3 crops, particularly in the developing world, where deficiency of zinc and iron is already a major health concern.C4 crops appeared to be less affected by higher CO2, which is consistent with underlying plant physiology, as C4 plants concentrate CO2 inside the cell for photosynthesis, and thus they might be expected to be less sensitive to extracellular changes in CO2 concentration.The researchers were surprised to find that zinc and iron varied substantially across cultivars of rice. That finding suggests that there could be an opportunity to breed reduced sensitivity to the effect of elevated CO2 into crop cultivars in the future.In addition to efforts to reduce CO2 emissions, breeding cultivars with reduced sensitivity to CO2, biofortification of crops with iron and zinc, and nutritional supplementation for populations most affected could all play a role in reducing the human health impacts of these changes, said Myers. “Humanity is conducting a global experiment by rapidly altering the environmental conditions on the only habitable planet we know. As this experiment unfolds, there will undoubtedly be many surprises. Finding out that rising CO2 threatens human nutrition is one such surprise,” he said.Other HSPH authors include Antonella Zanobetti, Itai Kloog, and Joel Schwartz.last_img read more

D’Tigress Start FIBA Women’s World Cup Campaign against Australia Today

first_imgAfter weeks of training which started in Atlanta and ended in Turkey, African Champions, D’Tigress will start their 2018 FIBA Women’s World Basketball cup campaign against Australia today by 12:30a.m. Nigerian time.D’Tigress who are ranked 34th in the world by FIBA will square up against world number 4, Australia at the San Cristobal de La Laguna, Santiago Martin Arena in Tenerife.Without any previous record of meeting, both sides’ target will be starting the tournament on a strong note with a win. Reacting before the game, D’Tigress Head coach Otis Hughley is confident of his team’s readiness to confront any opposition.“We were born ready for this. There is no point in coming to such events like this just to add to the numbers. We have done what we should have done within the time allowed for training and the general consensus in the team is that we are good to go.”D’Tigress having enjoyed an unprecedented support from the leadership of the Nigeria Basketball Federation are determined to repay the faith withworld-class performance at the highest stage of world basketball.Team captain, Adaora Elonu said she was grateful to the NBBF for their support.“We can’t thank the federation enough for this level of preparation. I have been around the national team set up for a while and I can confidently say this is the first time we’ve had this type of preparation.”She said the team is not under pressure heading into their first game as she promised that the girls are determined to try their best at the world cup.Besiktas of Turkey player, Evelyn Ahkator while echoing her team mates’ belief said that as African Champions, the onus lies on them not just to fly the Nigerian flag alone but that of every other basketball playing nation in Africa.“In 2017, nobody believed we could win the Afrobasket in Mali. It is our time to prove to the world that Nigeria is not a pushover.”The team will be hoping to make history as the first African team to win a world cup match and also record their first victory at the world stage.Share this:FacebookRedditTwitterPrintPinterestEmailWhatsAppSkypeLinkedInTumblrPocketTelegramlast_img read more