Why Climate Change May Affect the Foods We Eat

Climate change may one day affect the foods we eat: A new study led by the Harvard School of Public Health finds that crops which provide dietary zinc and iron to a big part of the global population will have significantly reduced concentrations of both nutrients. The researchers estimated that 2 billion to 3 billion people around the world get 70 percent or more of their dietary zinc and iron from grains, and this is particularly true in developing countries where zinc and iron deficiencies are a major problem. An estimated 2 billion people suffer from zinc and iron deficiencies, which causes a loss of 63 million life years annually from malnutrition, according to the study.

Iron deficiency is the most common and widespread nutritional disorder in the world, according to the World Health Organization (WHO). Two billion people, more than 30 percent of the world’s population, are anemic, many due to iron deficiency. Zinc deficiency is a serious health concern and in children can cause growth retardation. In both adults and children, it can cause loss of appetite and impaired immune function, according to the National Institutes of Health. Children in developing countries with zinc deficiency are at risk of contracting infectious diseases and even dying from them.

Other studies looked at crops grown in greenhouses and chambers with elevated carbon levels and found reductions in nutrients, but those studies faced criticism for using artificial growing conditions. There were experiments with free air carbon dioxide enrichment (FACE) technology which allowed crops to be grown in open fields with elevated levels of carbon, but the crop size was small. For this study, published May 7 in the journal Nature, researchers analyzed the data from 41 different types of grains and legumes in seven different FACE locations in Japan, Australia and the U.S. What they found are significant decreases in levels of zinc, iron, and protein in the grains. The zinc, iron and protein levels in wheat grains grown at FACE sites were decreased by 9.3 percent, 5.1 percent and 6.3 percent, respectively. Zinc and iron were also significantly decreased in legumes, although protein was not.

There are other reasons to be concerned about climate change

The latest report by the U.N. Intergovernmental Panel on Climate Change (IPCC) lists numerous reasons to be concerned about climate change. Low-lying coastal zones and small island develop states, plus other small islands will be on the front lines of climate change. They will likely experience storm surges, coastal flooding and sea-level rise. Large urban populations will be facing major impacts, including risks from “severe ill-health and disrupted livelihoods” plus extreme weather events which will lead to infrastructure and critical services breaking down. There will be mortality risks from extreme heat, particularly for urban populations and people who work outdoors.

The IPCC report also projects that there will be risks to the food supply from “food insecurity and the breakdown of food systems linked to warming, drought, flooding, and precipitation variability and extremes, particularly for poorer populations in urban and rural settings.” Rural areas face potential loss to livelihoods caused by lack of access to drinking and irrigation water and “reduced agricultural productivity, particularly for farmers and pastoralists with minimal capital in semi-arid regions.” California is currently experiencing its third year of drought. The drought has particularly hit farmers the hardest. Farmers in the San Joaquin Valley were told by the U.S. Interior Department’s Bureau of Reclamation earlier this year to expect no water deliveries. That means farmers must decide whether to tap further into underground water supplies or idle crops.

Image credit: Maurice