An article written for the ‘United Nations Academic Impact‘ (UNAI), by John Roy Porter, a Professor of agriculture and climate change at the University of Greenwich, in England, describes some of the more pressing impacts climate change has on agriculture. UNAI is a group consisting of the United Nations (UN), Researchers, Scholars and Universities, allied in an effort to better understand and report on global developments like climate change and sustainability issues. The article contends that if climate change is not immediately addressed it will seriously threaten the world’s food supply due to temperature rise, precipitation irregularities, droughts, sea level rise, and other things.

According to the Professor, “In the next 30 years, food supply and food security will be severely threatened if little or no action is taken to address climate change and the food system’s vulnerability to climate change.” He argues that projections conclude that there will be a significant reduction in the yield of maze and wheat, in the near future, due to climate change and that “in many parts of less developed countries in Africa and Central America, maize is a key component in the daily diet and plays a key role in achieving food security in those areas, with nearly 950 million metric tonnes consumed annually. Wheat also plays a central role in diets.  With nearly 700 million metric tonnes consumed annually on a global basis, wheat alone provides over 20 per cent of the world’s calories and protein. To ensure food security for the predicted population of 9.6 billion people by 2050 the FAO predicts that food production must increase by at least 60 per cent to meet the demand.” FAO is the Food and Agriculture Organization of the United Nations.

The article says that activities to counter climate change should proceed with urgency and that crop yields are already on the decline in Europe and southern Asia, but the article is particularly concerned about Developing Countries, it says “unfortunately, it is the populations in many tropical areas and the southern parts of Europe and North Africa who will pay a great price. These population groups – especially the poor – are the most vulnerable in terms of failing harvests, higher prices and malnutrition in the near future. This multi-faceted crisis will only increase pressure in other areas of the world to increase production, whilst basic living conditions in deprived areas further decrease.” To illustrate the real effect of temperature rise on food production the article claims that “there is no doubt in the evidence and conclusions of more than 1,000 global and regional studies, that a temperature rise of 1 to 2 degrees Celsius, [above the temperature before the industrial revolution in Europe], will generally mean a loss in yield of a number of crop varieties, both in the tropical and the temperate regions. An increase of 3 to 4 degrees later on in this century will have very severe consequences for global food security and supply.”

Climate change affects agriculture but it should be made clear that agriculture itself also contributes to climate change. As stated by a UN publication, “food needs to be grown and processed, transported, distributed, prepared, consumed, and sometimes disposed of. Each of these steps creates greenhouse gases that trap the sun’s heat and contribute to climate change. About a third of all human-caused greenhouse gas emissions is linked to food.” The publication states as well that “the largest chunk of food-related greenhouse gases comes from agriculture and land use,” which produce greenhouse gases, like Methane, caused by cattle rearing, for example when digesting animal feed cattle releases methane into the atmosphere. Nitrous Oxide is caused by fertilizer use, Carbon Dioxide (CO2) is caused by deforestation, including the burning of vegetation for land clearing. Also CO2 is derived from fossil fuels used by farm vehicles and the transportation of food and other food-related necessities.

In terms of individual agricultural products and their contributions to climate change, the publication says “Animal-based foods, especially red meat, dairy, and farmed shrimp, are generally associated with the highest greenhouse gas emissions.” Meat production is cited as a significant agricultural contributor to the emission of carbon dioxide, primarily due to land use, because to obtain the vast ranches required for cattle rearing, it is usually necessary to clear forests of trees and shrubs that normally act as important absorbers of carbon dioxide. Shrimp farms which utilize wetlands and mangroves, are also considered by the publication to be contributing to carbon emissions. It says when wetlands and mangroves are disturbed or eliminated, the carbon dioxide they store is released into the atmosphere. With respect to other agricultural products, the publication says “plant-based foods – such as fruits and vegetables, whole grains, beans, peas, nuts, and lentils – generally use less energy, land, and water, and have lower greenhouse gas intensities than animal-based foods.”

An article by CBC News on June 18, 2025, claims that the future will see a reduction in most crop yields due to climate change and that “certain crops in higher-income regions, such as corn and wheat in the U.S. Midwest and wheat in Canada’s Prairies, could see some of the bigger losses compared to crops in developing countries.” The article is basing its opinions largely on the findings of a study in the ‘Journal Nature’, with chief Author, Professor Andrew Hultgren of the University of Illinois. According to the article “the study looked at data about regional climates; climate impacts on specific crops; access to resources such as fertilizer and insurance and costs and benefits of different farming practices for farmers in 54 countries that grow corn, soybeans, rice, wheat, cassava and sorghum. The goal was to find out how farmers are adapting to weather shocks and the extent to which adaptation is offsetting the impacts of climate change.”

The article states that the availability of resources to adapt agriculture to climate change, in developed countries, will help to limit losses but not totally eliminate a decrease in output and revenue. It cites adaptation methods in Developed Countries like planting different varieties of crops, and finding new approaches to fertilization and irrigation as ways that could bolster production even though costs may be extravagant. The article says Canadian agriculture may be in a better position than agriculture most countries, mainly because adaptation is well on its way in Canada. It claims the President of the Western Canadian Wheat Growers Association “said he and other farmers are constantly improving their farming practices, technology, and changing their crops and varieties to suit changing conditions in the climate and the market,” and also “despite challenging swings between wet and dry conditions in recent decades,…’our yields still seem to be able to go up every year because of the way we change farming — the way we adapt to the climate, to the changes.’ “

Climate Scientists and other observers are pessimistic about Developing countries being able to agriculturally adapt with the adequate speed that is required to thwart the effects of climate change. An article on Nigeria’s adaptation in ‘agriculture and food security’ by the African Policy Research Institute (APRI), gives some credence to the pessimism. APRI summarizes its series of conclusions at the outset. It says agriculture in Nigeria is vulnerable to climate change but few urgent steps are being taken to address the issue. It says policies regarding agriculture, do not currently reflect climate change concerns and that adaptation methods regarding irrigation and weather resistant seeds, are negatively affected by funding, awareness and suitable infrastructure, among other things. Agriculture represents a significant percentage of Nigeria’s economy, as APRI put it “agriculture in Nigeria plays a crucial role in the economy, contributing approximately 19% to 25% to the country’s overall gross domestic product (GDP) between 2023 and the first quarter (Q1) of 2024.” Also the role of women that participate in the country’s agricultural sector is significant, APRI says “smallholder farmers, most of whom are women, predominantly characterize the agricultural landscape in Nigeria. These farmers typically engage in subsistence farming, focusing on food crops for local markets and producing over 60% of food production. They remain the backbone of Nigeria’s agricultural sector.”

The article contends that Nigeria’s agriculture is still, to a great extent, sustained by rainfall and favorable weather conditions, thus making it extremely vulnerable to climate change impacts, according to APRI, “extreme weather events, such as floods and droughts, have increasingly disrupted agricultural production in Nigeria. Key staples like rice, maize and sorghum are particularly affected, pushing many smallholder farmers and communities into cycles of poverty. The frequency of these climate-induced events has escalated, leading to severe consequences for food security and livelihoods.”

In a global context, agriculture emits less greenhouse gases into the atmosphere than most other major economic sectors and overall, industrialized Developed countries emit most of the world’s greenhouse gases. The Environmental Protection Agency reports that in 2022, in the United States, (the world’s second most prolific greenhouse gas emitter, behind China), agricultural production emitted only 10% of the national greenhouse gas emissions, residential and commercial activities13%, manufacturing and other industries 23%, electricity generation 25% and transportation emitted the most with 28%.

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