Climate Impacts on Agriculture and Food Supply

Overview

Agriculture is an important sector of the American economy. Harvesting, livestock, and seafood produced in the United States contribute more than $ 300 billion to the economy each year. [1] The agribusiness sector, including hospitality and other agriculture-related industries, contributes more than $ 750 billion to gross domestic product. [2]

Agriculture and fishing are highly dependent on climate. Higher temperatures and carbon dioxide (CO2) can increase yields in some areas. But to reap these benefits, nutrient levels, soil moisture, water availability, and other conditions must also be met. Changes in the frequency and intensity of drought and flooding can create problems for farmers and pastoralists and threaten food security [3]. Meanwhile, rising water temperatures are likely to change the habitats of many fish and shellfish species, potentially disrupting ecosystems. In general, climate change can be difficult to plant, care for animals and fish in the same way and in the same places as in the past. It is necessary to consider the effects of climate change, as well as other changing factors affecting agricultural production, such as B. Changes in agricultural practices and technologies.

Impacts on Crops

Crops grown in the United States are essential to the food supply here and around the world. U.S. farms supply approximately 25% of all grains (such as wheat, corn, and rice) to the global market. Changes in temperature, atmospheric carbon dioxide (CO2), and the frequency and intensity of extreme weather events can have a major impact on crop yields.

For any particular crop, the effect of increased temperature depends on the optimal temperature for the growth and reproduction of the crop. [1] In some regions, warming may benefit crops commonly grown there, or farmers may switch to crops already planted in warmer regions. Conversely, if the maximum temperature exceeds the optimum temperature of the crop, the yields will decrease.

Higher CO2 levels can affect yields. Some laboratory experiments show that high CO2 levels can accelerate plant growth. However, other factors such as changes in temperature, ozone, water, and nutrient restrictions can offset the potential yield increase. For example, if the temperature is above the optimum for the crop, crop growth can be reduced or reversed if there is not enough water and nutrients. High CO2 levels are associated with reduced protein and nitrogen levels in alfalfa and soybean crops, resulting in decreased quality. Decreased grain quality and forage can reduce the ability of pastures and pastures to support animal husbandry.

Extreme temperatures and rainfall can hinder crop growth. Severe events, especially floods and droughts, can damage crops and reduce yields. For example, in 2010 and 2012, high overnight temperatures affected corn crops in the U.S. corn region, and early hatching due to the hot winter caused $ 220 million in damage to Michigan cherries in 2012. [a]

Drought can be difficult to manage in areas where rising summer temperatures are causing the soil to dry out. In some areas, more irrigation is possible, while in others the water supply may be reduced and less water can be used for irrigation when more is needed.

Many weeds, pests, and fungi thrive in warmer, wetter climates and higher CO2 levels. Farmers in the U.S. are currently spending. of more than $ 11 billion per year in fighting weeds that compete with plants for light, water, and nutrients. [1] The size and distribution of weeds and pests will increase with climate change. This could create new problems for crops by farmers who have not been exposed to these species before.

High CO2 accelerates plant growth and reduces the nutritional value of most foods. Rising levels of carbon dioxide in the atmosphere are lowering the concentration of proteins and essential minerals in most plant species such as wheat, soybeans, and rice. This direct impact of increased CO2 on the nutritional value of crops is a potential threat to human health. Human health is also threatened by the increased use of pesticides due to increased pesticide pressure and decreased pesticide effectiveness. [3]

Impacts on Livestock

Every year, Americans consume more than 36 million tons of meat and poultry. The livestock and poultry industry accounts for more than half of U.S. farm income, typically in excess of $ 100 billion a year. Climate change can affect animals directly and indirectly.

Heatwaves, which are expected to intensify due to climate change, could pose an immediate threat to animals. Exposure to high temperatures in 2011 resulted in more than US $ 1 billion in heat-related losses for agricultural producers. [1] Heat stress affects animals directly and indirectly. Over time, heat stress can increase susceptibility to disease, decrease fertility, and decrease milk production.

Drought can endanger pastures and food. Drought reduces the amount of high-quality food available for grazing animals. Some regions may experience longer and more severe droughts due to higher summer temperatures and less rainfall. For grain-dependent animals, changes in yield due to drought can also be a problem.

Climate change could increase the spread of pests and diseases in animals. Early spring and milder winters make it easier for some pests and pathogens to survive. Moisture-dependent pathogens can thrive in regions with high rainfall. [6]

Potential changes in veterinary practice are likely to occur in response to climate-related changes in pest, pest, and microbial abundance, including increasing the use of pesticides and other animal health products. This can increase the risk of pesticides entering the food chain or lead to the development of pesticide resistance, affecting the safety, distribution, and consumption of animal and aquaculture products [3].

Increasing carbon dioxide (CO2) levels can increase pasture productivity but also decrease pasture quality. Increasing atmospheric CO2 can increase the productivity of feed mills. However, the quality of some pastures deteriorates with increasing CO2 content. Therefore, cattle should eat more to get the same nutritional benefits.

Impacts on Fisheries

American fishermen catch or catch five million tons of fish and shellfish annually. [7] U.S. fisheries. contributes more than $ 1.55 billion annually to the economy (since 2012). Many fisheries face many challenges, including overfishing and water pollution. Climate change could increase this pressure. Temperature changes, in particular, can have important consequences.

The range of distribution of many fish and shellfish can vary. In the waters of the northeastern United States, many important types of economies have moved north since the late 1960s. The three species have shown [pictured left] (American lobster, red toothpick, and black bass) moved an average of 119 miles to shore. North. † [nine]

 Many aquatic animals can find cooler areas with streams and lakes, or move north along the coast or into the ocean. However, moving to new areas could put these species in competition with other species for food and other resources, as described on the Ecosystem Effects page.

Some cases of sea dizziness are associated with climate change. Warmer water temperatures and higher salinity in the estuaries led to the spread of oysters north along the Atlantic coast. The winter tide in the Arctic is contributing to the disease of Bering Sea salmon and the decrease in the number of Yukon Chinook salmon. Finally, higher temperatures lead to epidemics of coral, algae, and swimming. [3], [10]

Temperature and seasonal changes can affect breeding and migration times. Many stages of the life cycle of aquatic animals are determined by temperature and changing seasons. For example, in the Northwest, warmer water temperatures can affect the life cycle of salmon and increase the likelihood of disease. It is expected that, along with other climatic effects, these effects will lead to a strong decrease in salmon populations [1], [11], [12].

In addition to increasing temperatures, the acidic atmosphere of the world’s oceans is becoming acidic due to increasing atmospheric carbon dioxide (CO2). Increased acidity can harm mollusks by weakening their shells, which are formed as a result of the removal of calcium from seawater. [10] Acidity also threatens the fragile structure of the ecosystem on which some fish and crustaceans depend. [1], [13]

International Impacts

Climate change is likely to affect food security globally, regionally, and locally. Climate change can disrupt food availability, limit food access and affect food quality. For example, expected temperature rises, changes in rainfall patterns, changes in extreme weather events, and decreases in water availability can reduce agricultural productivity. Increases in the frequency and severity of extreme weather events can also disrupt food supplies, and food prices are expected to rise more frequently in the future due to extreme weather events. Rising temperatures can promote deterioration and infection.

Internationally, these effects of climate change on agriculture and food supply are likely to be comparable to those in the United States. However, other stressors, such as population growth, may exacerbate the impact of climate change on food security. Opportunities for adaptation, such as changing farming or livestock practices or improving irrigation, are more limited in developing countries than in the United States and other industrialized countries.

Any climate change in food distribution and transportation, both nationwide and within the country, could have a major impact not only on food safety and quality but also on food access. For example, the food transportation system in the United States often carries large amounts of grain by water. In extreme weather conditions, there are little or no alternative means of waterway transportation. The high temperatures and drought in the summer of 2012 led to one of the worst summer droughts experienced in the country, severely affecting the Mississippi region, a major intercontinental waterway for Midwestern agriculture.

This drought resulted in huge food and economic losses due to reduced maritime traffic, the volume of goods being transported, and the number of Americans working in the trailer industry. The drought in 2012 was immediately followed by the flooding of the Mississippi River in the spring of 2013, which disrupted the shipping and transportation of food. Such transportation changes reduce the ability of farmers to export their grain to international markets and may affect world food prices.

The impact on the global food supply is of concern to the United States, as food shortages can lead to human and national security crises. They can also raise food prices in the domestic market.