Are we facing a less nutritious future?
Rob Percival - 12 May 2014
Carbon dioxide is present in the atmosphere today in a concentration that has not been seen since sabre-toothed cats and mastodons roamed a planet on which humans had never set foot - it was three million years ago and we had not yet evolved.
In recent years we have poured huge amounts of carbon dioxide into the atmosphere. We know that rising global temperatures are the result. But a study published last week revealed that increased levels of carbon dioxide will also make some of the world's most important foods less nutritious - and this has significant implications for millions of people.
Prior to the Industrial Revolution, the level of carbon dioxide in the atmosphere was 280 parts per million (ppm). This reached 400ppm for the first time in human history in 2013. April of this year then broke a new record – becoming the first month where the level exceeded 400ppm every day.
These emissions are due in part to our mistreatment of soil. Soil can either release carbon or it can capture it, the organic matter in soil being capable of sequestering carbon from the air. Organic farming systems have been shown to increase the organic matter in soil, but decades of intensive agriculture have done just the opposite, and rising emissions are the result.
And these emissions are now being shown to have some unexpected consequences. The study, published in the journal Nature, found that higher carbon dioxide levels significantly reduce the levels of essential nutrients in four key crops: wheat, rice, maize and soybeans. Wheat grown in higher carbon dioxide levels was shown to have 9% less zinc, 5% less iron, and 6% less protein; the other crops showed similar results.
Billions of people around the world are dependent on these crops. And with more than two billion people already suffering from zinc and iron deficiencies, the depletion of these nutrients in years to come is likely to exacerbate an existing public health crisis, posing a fundamental challenge to global food security.
And a challenge to our understanding of ‘health’
We tend to think of health as simply being the absence of illness. We would do better to think of it as the wholeness and integrity of living systems.
On this view, the health of individuals and communities cannot be separated from the health of the ecosystem - healthy soils produce healthy crops that foster the health of animals and people. This means that whether we’re growing, processing, distributing, or consuming food, we should seek to sustain and enhance the health of each eco-system component, from the smallest organisms in the soil to humans, plants and animals.
This broader perspective helps us understand that the health of individuals cannot be separated from the environment in which they live. Many of us are overweight. But many of us live in areas where there is no green space, where roads are so choked with cars that walking or cycling are unappealing or unsafe, and where fresh food can be expensive and can sometimes be hard to come by. Healthy people need healthy places - health extends beyond the individual, to a larger system.
This broader perspective may be necessary if we are to curb our carbon emissions, if we are to feed ourselves sustainably, if we’re to achieve a more positive future than the distant mastodon. We should recognise that health extends beyond the individual - into the wholeness and integrity of living systems.
Rob is Policy Officer for Food & Health at the Soil Association.