The food production set-up has evolved in recent decades, increasing the availability of food. Experts say this can easily be underestimated by the enormous impact that food production has created to support human societies trying to reach today’s nutritional needs, as we deal with the world’s rapidly growing population.

However, they note that feeding the population generates environmental costs, such as loss of biodiversity, extensive land use, use of large amounts of freshwater, pollution of the air, waste and pollution by nitrogen and phosphorus in the soil.

Dr Christophe Ngendahayo, NCDs and climate health trainer with the World Organization of family doctors (WONCA), says climate change refers to the increase in average rates of temperatures over an extended period of time.

He says this is due to emitted air pollutants, also called greenhouse gases.

Farming methods and other human activities, he says, contribute to changing the earth’s climate, leading to increasing greenhouse gas concentrations in the atmosphere.

"Conversely, the changing climate, in return, presses excessive heat to plants and hampers crop production,” he says.

He further explains that climate extreme events and rise in temperature threatens food production.

Projected increases in temperatures, changes in precipitation patterns, changes in extreme weather events and reductions in water availability, may all result in reduced agricultural productivity, causing drought, malnutrition, and migration, Ngendahayo says.

Meanwhile, increasing evidence indicates that the rise in concentrations of carbon dioxide have adverse effects on the composition of the main cereal crops such as rice and wheat, including reduced protein levels, a variety of B complex micronutrients, and vitamins.

"Climate and other environmental factors change also reduce the overall yield of vegetables and legumes, which has important implications for the prevention of non-communicable diseases,” he says.

Effects on health

Experts say the global pollution, climate change, biodiversity loss, altered biogeochemical cycles, changes in land use and resource scarcity are decreasing the quality of the air we breathe, the water we drink, and the food we eat; exposing us to new diseases.

Ngendahayo says it also diminishes our access to freshwater and other resources; and increases incidence of natural disasters.

All of these results, he says, have negative consequences for our nutrition, mental health, and susceptibility to injury and illness today.

For instance, he says, air pollution kills more than malaria, tuberculosis and AIDS.

He points out that three great pandemics plague the modern world; obesity, malnutrition, and climate change due to their effects on human health and natural systems on which human beings depend.

Climate change and the global rise in temperature will result in an increased incidence of infectious diseases; for example, more floods will result in more waterborne diseases and increased temperature will favour the transmission of mosquito-borne pathogens.

The same substances in the atmosphere that are responsible for air pollution are also responsible for climate change. And climate change will have a negative impact on air pollution; for example, by increasing incidences of forest fires which also affect our health.

Way forward

Ngendahayo says public health, agriculture professionals, economists and other experts have great capacity to improve human nutrition as well as control of climate-sensitive infectious diseases.

He says that it is also ideal to prepare your own practice for possible disasters by assessing and planning for threats such as extreme heat, flooding, or storms.

In addition to this, the medic says use forms of transport that involve physical activity, such as cycling and walking, have the dual benefit of reducing emissions and protecting against multiple diseases.

Besides, switching to renewable energy sources and away from fossil fuels, such as coal, could greatly reduce the health and environmental impacts of fossil fuel-related air pollution.

Ngendahayo says reducing meat consumption, especially beef, and consuming fish, chicken, egg, and dairy products in moderation can help minimise livestock and conserve the environment. 

Avoid buying food with excess packaging, and when it is necessary to use packaging, opt for a reusable bag.

"Avoid burning agricultural wastes, avoid food wasting and practice full use of food to offset the impact of climate change on scarcity of food,” he adds.

Ngendahayo says it’s ideal to start planting vegetable gardens at home or in the neighbourhood, and that planting brings people closer to food; increases access to food and keeps the environment green.

"Be active in advocating for effective evidence-based health policies and engaging with media and stakeholders to raise awareness of planetary health,” he urges.