Ending hunger, improving nutrition, and ensuring food security for all are some of the most important goals humanity faces. After all, eliminating poverty and hunger are the top two of the seventeen UN Sustainable Development Goals. However, climate change is threatening global agriculture and food security, which means eliminating world hunger and preventing food insecurity will be even more challenging. Climate change is causing extreme weather events, like droughts, floods, and storms, to be more frequent and severe, as well as increasing global temperatures and precipitation patterns. All of these factors cause agricultural production to face increased crop failure, new and increased amounts of pests and diseases, and loss of livestock. Those who are already vulnerable and food insecure, especially those whose livelihoods are based on agriculture, are the first to be impacted. According to the Food and Agriculture Organization of the UN (FAO), around 800 million people are currently chronically undernourished. However, if no action is taken, and as the effects of climate change worsen, the possibility of ending hunger around the world will be increasingly threatened, with even more people becoming affected. Growing population, increasing incomes, and urbanization are all leading to changing demand for food. The FAO estimates that, in order to satisfy the growing demand, food production will need to increase by more than 60% in the upcoming decades. Without even considering the effects of climate change, population is increasing exponentially, but food production is only increasing arithmetically, which means that over time everybody, not just those who are currently food insecure, will be affected. Building resilience into agricultural production systems, and altering them all together, along with mitigating climate change are the best ways to deal with the current and emerging effects of climate change on food security. According to the United Nations Department of Economic and Social Affairs, the World Food Summit of 1996 defined food security as “existing when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food to meet dietary needs for a productive and healthy life.” A person who is food secure will always have physical access to food, as well as the financial ability to purchase it. Not only that, but the food has to be nutritious, non-contaminated, and diverse enough that it is appropriate for their dietary needs and food preferences. More specifically, there are four dimensions of food security. Food availability is the physical availability of food, and addresses the “supply” side of food security. Food access refers to a person’s economic and physical access to food. Food utilization is the way the food is used and assimilated into the body. The fourth dimension, food stability, relates to the stability of the other three dimensions over time. Food security only occurs when all four of these dimensions occur simultaneously.

The diagram below from the FAO summarizes how climate change affects food security and all four of its dimensions.

Climate change has consequences for land and ocean temperature change, sea-level rise and ocean acidification. It also affects spatial changes in precipitation, both in intensity and in seasonal distribution. These consequences and effects caused by climate change then affect agricultural production systems, whether directly or indirectly, short term or long term. Climate change is impacting agricultural production as it impacts the conditions in which the agricultural activities take place. Ecosystems and its inhabitants are adapted to the climatic conditions, and when these conditions change, the productivity and populations of plants and animals are affected. Direct impacts on agriculture due to climate change include those directly caused by a modification of physical characteristics like temperature levels during the year and water availability on a specific agricultural production. Indirect effects of climate change affect production through changes in other species like pollinators, invasive species, pests, and disease. Short term effects are caused by more frequent and intense extreme weather events, and long term effects are caused by changing temperatures and precipitation patterns. It is evident that all of these factors have hurt crop production in several regions of the world, with effects including production shortages and price spikes. Other factors for the shortages and rising prices include the increasing demands for meat and dairy, fuel prices and displacement of food crops. Still, as one example, according to the US Government Accountability Office (GAO), there is evidence that climate change has already negatively affected wheat and maize yields in many regions and at the global level. Stanford University’s David Lobell and colleagues found that rising global temperatures caused global maize and wheat production to decline by 3.8% and 5.5%, respectively, from 1980 to 2008.

Another important issue to discuss is the effects of climate change on pests and diseases. An increase in population or migration means more pests in areas less equipped to defend itself, which means potentially more negative effects. A study done by Dr. Sam Myers, a medical doctor and senior research scientist studying environmental health at the Harvard T.H. Chan School of Public Healteh has found that increasing temperatures also means an increase of crop pests. Currently, according to Myers, pests are the cause of 25-40% of all crop loss, and this will only increase in the future as temperatures increase. Along with an increase in population, pests will also be able to expand physically, which means they can move to areas where there are no current defenses against them by plants. Also, birds, a predator of crop pests, may have their migratory patterns affected by climate change, which may mean that they won’t be able to keep these populations in check. Overall, climate change causes temperature warming, which allows for an increase in crop pest populations, which leads to a reduction of future harvests throughout the world and further reduces food security.

Similarly, pollinators that are vital to our food supply are being threatened and driven to extinction by human-made pressures. The rapidly increasing human population is reducing the availability of natural habitats, due to urbanization and an increasing demand for production areas. This threatens food supplies and millions of livelihoods, according to the first global assessment of pollinators. The assessment is a two-year study conducted and released by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). Vera Lucia Imperatriz-Fonseca, Ph.D., co-chair of the assessment and Senior Professor at the University of São Paulo stated that “Pollinators are important contributors to world food production and nutritional security. Their health is directly linked to our own well-being.” Bees, butterflies, flies, birds, bats, and other animals all contribute to pollination. Crops that are pollinated include those that provide fruit, vegetables, seeds, nuts and oils. Many of these crops provide vitamins and minerals, without which the risks of malnutrition could increase. Some of the crops are also vital to livelihoods, as they represent an important source of income in developing countries from the production of coffee and cocoa. More than 3/4 of the world’s food crops rely at least partially on pollination. Direct contributions by pollinators supplies between $235 billion and $577 billion of annual global food production. The amount of agricultural production that depends on animal pollination has increased 300% over the last 50 years, but these crops have been lagging in growth and stability of yields compared to crops that don’t depend on pollination. 16% of insect pollinators have the possibility of becoming extinct, with that possibility only increasing over time. IPBES Vice-Chair, Sir Robert Watson said that “Wild pollinators in certain regions, especially bees and butterflies, are being threatened by a variety of factors. Their decline is primarily due to changes in land use, intensive agricultural practices and pesticide use, alien invasive species, diseases and pests, and climate change.” The FAO released a report explaining their position that it is most plausible that the most important effect of climate change on pollination is an increase in temperature. The FAO continued stating that there are “three possible scenarios for responses to large-scale climatic changes”. The first is adaptation to the new environment, but this is unlikely because climate change is occurring too fast for populations to adapt genetically through evolution. The second scenario is that species will relocate to a more suitable environment. However, even though crops and managed pollinators could be moved easily, moving food production has socio-economic consequences, and there is no guarantee that wild pollinators can move with them. The third scenario is extinction.

It is important to note that although the effects of climate change are impacting agricultural production, agricultural practices are also worsening production overall. In an attempt to control the factors around production, increased use of pesticides and unsustainable practices are worsening the effects and leading to a negative cycle of trying to fix effects caused by short term “helpful” actions.

According to the FAO, droughts, floods, and storms triggered by climate change have been rising in frequency and intensity. They have been increasing damage to agricultural sectors, especially developing countries, causing an increase in food insecurity. The report released by the FAO found that 25% of negative economic impacts of climate-related disasters in developing countries were on the crop, livestock, fisheries, and forestry sectors. The report states that extreme weather events regularly have a big impact on agriculture and hinder the eradication of hunger and poverty. “This year alone, small-scale farmers, fisherfolk, pastoralists and foresters – from Myanmar to Guatemala and from Vanuatu to Malawi – have seen their livelihoods eroded or erased by cyclones, droughts, floods and earthquakes,” said FAO Director-General José Graziano da Silva. Severe storms and flooding destroy current crops and impact the types of crops that can be planted in the future. Many Asian countries are vulnerable when it comes to floods and storms. In Pakistan, the 2010 floods caused crop production losses and directly affected cotton ginning, rice processing, and flour and sugar milling, with imports for cotton and rice spiking. About 50% of the $10 billion in total damages due to the floods fell on the agricultural sector. Furthermore, as the frequency and intensity of severe weather increase, there is an increasing risk of storm damage to transport and distribution infrastructure, which would disrupt food supply chains. Agriculture is the biggest consumer of US water resources, accounting for over 80% of the US’s water use. However, climate change is leading to a greater uncertainty of the availability of water in many regions now and in the future. It will affect precipitation, runoff and snow melt, water quality and water temperature. Also, snowpacks are less than normal, which could reduce the water availability for agriculture. The impacts of affected rainfall patterns may also be that heavy rainfall could increase pollutants, which would be harmful for the quality of raw water for agriculture and drinking purposes. Drought is particularly impactful on production, and according to the Intergovernmental Panel on Climate Change (IPCC), droughts are likely to intensify due to climate change. Increased precipitation intensity and variability are projected to increase the risks of flooding and drought. The FAO report stated that over 80% of the damage and losses due to drought worldwide between 2003 and 2013 affected the agriculture sector, specifically crop production and livestock. In September 2012, the US Department of Agriculture announced that droughts caused more than 2,000 US counties to be considered disaster areas. It was the most intense and extensive drought in the last 25 years, and it destroyed crops like corn and soybeans, which caused a ripple effect on the price of food as well as a decrease supply and availability, which adds to food insecurity. Drought has been especially harmful for sub-Saharan Africa, where the agriculture sector usually contributes to 25% of GDP, and has accounted for 90% of production losses on agriculture. Between 1991 and 2013 in sub-Saharan Africa, droughts caused an estimated $30 billion in total crop and livestock production losses.

It is interesting to add that the quality of food grown might also be affected by climate change, not just the production. According to Dr. Myers, research shows that certain foods can lose some of their nutritional value when grown at high levels of atmospheric carbon dioxide. This phenomenon was tested by Myers and his colleagues when they grew wheat and corn under elevated and normal carbon dioxide levels. The elevated carbon dioxide level represented the estimated atmospheric level in 50 years. They found that the crops grown under these levels had lower levels of protein, zinc, and iron. This could worsen the issue of nutrient deficiencies, specifically zinc and iron, which are already affecting a large percent of the population today. 200 million more people across the world could develop a zinc deficiency, and the 1 billion people who already have it could have their deficiency worsen. There would be similar effects for iron and protein deficiencies. However, more research needs to be conducted on this issue, as researchers still do not understand why carbon dioxide levels affect nutrient levels.

Animal agriculture is also both impacting and being impacted by climate change. According to Human Society International, “the farm animal production sector is the single largest anthropogenic user of land, contributing to soil degradation, dwindling water supplies, and air pollution.” The sector includes meat, egg, and milk production, along with feed grain production to feed the animals. It requires water, energy, and chemicals during the whole process of feeding and transporting. This means that it significantly contributes to climate change. According to the FAO, the animal agriculture sector accounts for almost 18% of “human-induced greenhouse gas emissions”. In every step of production, these gases are released into the atmosphere, contributing to climate change. The animals contribute to the production of all three major greenhouse gases, and when populations of these animals rise, so do emissions. According to the US Department of Agriculture, “GHG emissions from livestock are inherently tied to livestock population sizes because the livestock are either directly or indirectly the source for the emissions.” Carbon dioxide is largely known to have the biggest impact of the greenhouse gases on global climate, due to the volume of its emissions and the fact that it remains in the atmosphere for an extremely long period of time, for possibly centuries or millennia. The farm animal sector alone is responsible for 9% of annual anthropogenic carbon dioxide output. Alterations in animal agricultural practices and animal consumption must occur to change this.

Climate change and population growth are also causing stress on animal agriculture. Climate change is threatening livestock production because it affects the quality of animal feed and forage, water availability, animal and milk production, diseases, reproduction, and biodiversity. All of these impacts are mainly because of an increase in temperature, atmospheric carbon dioxide levels, variations in precipitation, and a combination of them as well. Temperature affects water availability, animal production, and animal reproduction and health. Forage quality and quantity are impacted by the increasing temperature, carbon dioxide, and variation in precipitation. Livestock diseases are impacted by temperature and precipitation variation. Animal production will be limited by an increase in water consumption, agricultural land demand growth as a result of a 70% growth in population, and finally food security concern, partially caused by the increasing amount of grain harvest used to feed the livestock. Since the livestock sector contributes to the climate change that’s impacting it, this sector will be an important player in the mitigation of greenhouse gas emissions, as well as an improvement in global food security. Animal diversification is one solution for minimizing the effects of climate change, and a transition to sustainable livestock production will be an important solution for mitigating climate change.

Animals are also causing our current food system to be extremely inefficient. The food system is currently driven by meat and dairy production. Like stated before, there are around 800 million people around the world who are undernourished, but the world produces enough calories to feed 10-11 billion people. How does this add up? The truth is, the majority of the calories grown are fed to livestock. However, for every 100 calories of grain fed to livestock, only 3 calories of beef are produced in return. In fact, according to One Green Planet, if one person stopped eating meat for one day, they could save enough grain to feed 40 people. If we shifted the grain fed from animals to people, 1.4 billon more people could be fed.

Protecting food security is about protecting human rights and human dignity. Therefore, there needs to be enough food for everyone and everyone needs to be able to have physical and financial access to it. It is a person’s right to be able to have the ability to feed themselves and survive. Climate change has been affecting livelihoods, decreasing food production, and aggravating hunger and poverty through intense weather events, rising temperatures, precipitation levels, water availability, and more.

To feed the growing global population, and to provide the basis for economic growth and poverty reduction, climate change must be mitigated and agriculture must be reformed. Decreasing greenhouse gas emissions by reducing fossil fuel combustion and deforestation, as well as transforming our energy systems are all steps in the right direction in mitigating climate change. In terms of agriculture, it will need to transition to more productive systems that use inputs efficiently, allow less variance, and lead to greater stability in their outputs. The systems will also have to be more resilient to risks and long-term climate variability. All of this must be done without draining natural resources and by emphasizing renewable energy over the use of fossil fuels. It is necessary to act now and do your part in mitigating climate change. It is almost impossible to completely reverse the effects of climate change, but it can be mitigated to help keep it at a level where it will still allow everyone food security and adequate nutrition. Climate change, if not mitigated, will cause long-term changes in weather conditions. These changes will seriously affect all four dimensions of food security. The effects are already being felt in global food markets, and will continue to be felt where supply chains are disrupted, market prices increase, livelihood is destroyed, and human health is jeopardized.


If you find the topic of food security to be fascinating, check out this video from National Geographic where a panel discusses how “research, technology, policy, and engagement with local farmers could help build a comprehensive strategy for improving our food system.”

Also check out this video regarding a report that “describes the potential effects of climate change on global food security and examines the implications of these effects for the United States.”