Expert Speak Terra Nova
Published on Dec 05, 2022
Global food insecurity is aggravated largely due to climate phenomena. The third brief of this four-part series explores the link between climate change and food security
Understanding climate change, health, and food security: Climate change and food security Climate change has worsened food and water security. Temperature increases beyond 1.5°C would alter terrestrial ecosystems and shift climate zones, which, in turn, will affect agriculture and livestock productivity. Warming oceans, which absorb more heat than land, will impact the productivity of fisheries and aquaculture. Together with more extreme weather events and sea-level rise, this will exacerbate inequities in accessing food and increase poverty. The biggest impacts are being seen in Africa, Asia, and Central and South America. Four key crops—wheat, rice, corn, and soybean—provide half of the world’s calories. The yields of these crops are predicted to fall—corn by 20-40 percent, wheat 5-50 percent, rice 20-30 percent, and soybean 30-60 percent—with the current model of climate change compared to unchanging climate. Increasing temperatures also reduce the nutritional quality of foods, so people will need more for the same benefit. Yield loss and reduced nutrition together with the increasing population, will exacerbate poverty, put more pressure on land, and compromise climate mitigation. Simultaneously, food systems also have environmental impacts. About 50 percent of all ice- and desert-free land is used to grow food, with 73 percent of deforestation and 80 percent of biodiversity loss linked to food systems, which also use 70 percent of water and cause 80 percent of water pollution. Food systems are responsible for about one-third of global anthropogenic GHG emissions through three pathways (Figure 1). Agriculture and livestock generate emissions through methane and nitrous oxide from enteric fermentation in ruminants, and their manure, as also from synthetic fertilisers and flooded rice fields. This contributes 10-14 percent of total GHG emissions, which could increase to 40 percent% by 2050. Land-use change contributes to 5-14 percent of emissions mainly through deforestation and the destruction of peatlands for agriculture. Deforestation also offers opportunities for zoonotic diseases to spill over from wild animals to livestock and humans. Finally, food processing, transport, and consumption together contribute 5-10 percent of GHG emissions. Figure 1. One-third of global GHG emissions come from food systems. This graph shows the distribution of GHG emissions assigned to various food systems activities, calculated for 2015.  Food system emissions also offer opportunities for climate change mitigation through four key pathways. These include improved crop and livestock management, land-use change, food value chains, and food consumption patterns including reducing food waste. Consumer dietary choices are a key to decisions on what to grow, how to process and consume it. Further, there are synergies and trade-offs that often make mitigation decisions difficult. For example, closing the ‘yield gap’ will require more water and fertilizers, but both contribute to GHG emissions. Agri-food systems consume about 30 percent of the world’s energy. Renewable energy can play a crucial role in meeting the food sector's electricity, heating, cooling, and transport needs. For example, solar irrigation produces 95-98 percent reduced emissions compared to pumps powered by grid electricity or diesel fuel. Biomass by-products from agri-food activities can be used to produce energy for processing, storage, and cooking. Fossil fuels supply 80 percent of India’s energy needs, including that for agriculture, but natural gas and solar energy are expected to show spectacular growth (Figure 2). India’s ambitious plans for hydrogen would also make her a leader in new age fuels. Figure 2. Energy demand and forecast for India. (Left) Total primary energy demand, 2000-2020 (red circles) and contributions from different fuel sources. (Right) Changes and projected changes in coal and solar energy capacity, 2010-2040.>.

Food security

Food security includes the availability and access to food and its utilisation. Between 1961 and 2020, the world population increased 2.6 times and food production increased 2.9 times while using 5 percent more land. This was achieved through breeding techniques and new crop varieties, and intensive use of water and chemical fertilisers, which have environmental costs. Even though the world produces sufficient food, undernourishment has decreased only marginally from 13.2 percent in 2001 to 8.9 percent in 2019. Globally, about 800 million people are undernourished, of which 418 million live in Asia and 282 million in Africa.

Even though the world produces sufficient food, undernourishment has decreased only marginally from 13.2 percent in 2001 to 8.9 percent in 2019.

The Global Hunger Index combines four key indicators—undernourishment, child wasting, child stunting, and under-5 child mortality—into a single index score to quantify hunger. The problem is most severe in South Asia and Sub-Saharan Africa (Figure 3). Of the 121 countries for which data was assessed this year, India was ranked 107 with a score of 29.1, indicating serious hunger. Energy or calories are a standard measure of food supply. Globally, the per capita calorie supply has increased consistently since 1961, including in Asia and Africa. However, inequalities exist within countries with regards to access to food and nutrition, which is quantified on a scale of 0 (no inequality) to 1. For most Asian and African countries, it ranges between 0.25 to 0.45, and has increased during the COVID years, signalling increasing inequalities. For India, it increased from 0.25 to 0.29 in 2021. Figure 3. The Global Hunger Index 2022, showing serious to alarming rates of hunger in South Asia and Sub-Saharan Africa.>.

The protein challenge

Beyond calories, proper nutrition requires macronutrients, especially proteins that are essential for growth and maintenance. Though the global average per capita protein supply increased from 61 to 82 grams between 1961 and 2019, about one billion people get insufficient protein, the problem being most severe in Central Africa and South Asia, where about 30 percent of children get too little protein. According to the Indian Dietetic Association, India’s vegetarian diet is 84 percent protein-­deficient, and most Indians do not get the daily recommended 0.8-1 gram protein per kilogram body weight. Human diets include both animal and plant proteins – the global average being 40 percent and 60 percent, respectively, with wide variation across regions (Figure 4). Between 1961 and 2017, the average daily per capita protein supply in India increased from 52 to 65 grams, with animal protein consumption doubling from 12 percent to 23. Animal-based proteins are considered “complete”, while plant-based proteins, with the exception of pulses, some nuts and seeds, often lack some essential amino acids. Studies also show better digestibility of animal-based proteins with the recommendation to supplement childhood diets to reduce stunting. Figure 4. Daily per capita protein supply from animal- and plant-based foods across world regions. Daily per capita protein supply is shown in grams per person per day.  The protein challenge is to address its deficiency by supplementing diets with high quality proteins with minimal GHG emissions. Beef, lamb and mutton are emissions-intensive due to the use of farmland and pastures, deforestation, and cattle emitting methane. But eggs, poultry, fish, pork and milk provide high quality animal proteins with reduced emissions (Figure 5). Several new technologies are also transforming food systems. Niche proteins, such as insects and seaweed, are being explored as alternatives to animal proteins. Yeast as a source of protein or engineered to produce animal and plant proteins, and cultured meat provide familiar sources of protein without the need for industrial-scale farming and its associated emissions. Figure 5. Greenhouse gas emissions per 100 grams of protein, shown in kilogram CO2 equivalents.>. Insects are a nutrition-dense source of protein eaten by about 2 billion people worldwide. Around 2,000 insect species are eaten across several countries in Africa, Asia, and South America. Insect cultivation has lower emissions as it uses a fraction of the land, energy, and water. For comparable protein yields, crickets produce up to 80 percent less methane than cows, 8-12 times less ammonia than pigs, are 12-25 times more efficient at converting their food into proteins, and use only about 12 percent of the land compared to beef. Food waste, which contributes significantly to emissions, can be recycled (instead of composting) by feeding it to insect larvae. Replacing half of the meat eaten worldwide with mealworms and crickets can cut farmland use by a third and reduce emissions. However, there are significant cultural barriers to consuming insects. Human health, diet, and the environment are inter-linked. A 2016 report showed that partially replacing meat with plant-based foods could reduce global mortality by 6-10 percent, reduce food-related emissions by 29-70 percent and gain financial benefits of US$1-31 trillion by 2050. A switch to vegan diets in rich countries was found to lower premature mortality by 12 percent and reduce GHG emissions by up to 84 percent.

A switch to vegan diets in rich countries was found to lower premature mortality by 12 percent and reduce GHG emissions by up to 84 percent.

Among several mitigation measures, our response will require deploying biotechnology to develop more efficient crops; improving soil health through microorganisms; reducing enteric fermentation through animal feeds; shifting food production, processing, and transport to cleaner energy. There is also a rich heritage of indigenous foods worldwide, particularly in India, which can enhance the quality of diets towards improved health and food security, but investment is needed in the research, development, and promotion of these foods.
Read Part IV of the series that delves into the climate action and mitigation.
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Shahid Jameel

Shahid Jameel

Dr. Shahid Jameel established and for 25 years led the Virology Group at the International Centre for Genetic Engineering and Biotechnology New Delhi. He was ...

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