Since agriculture relies on resources from the natural world, this industry is especially susceptible and sensitive to a changing climate. Climate change alters natural resources and processes involved with growing crops and raising livestock, setting up a potentially dangerous situation. The North American agricultural industry plays an important role in economic and social systems that if yields were to decline and livestock failed to produce enough, there would be a global food crisis.1 This webpage takes a look at the prominent hazards and vulnerabilities to agriculture posed by climate change in the United States and then possible adaptation strategies that protect and increase resilience of North American crops and livestock.
Direct and Indirect Hazards
The primary concern is that climate change will have a negative impact on crop yields and livestock production, both of which will be directly impacted and are expected to diminish in the coming decades.2 If these two industries were to decline, there would be a major risk for food security around the globe and it would also create economic turmoil for the agricultural industry.2 These direct and indirect hazards stem from extreme and increased weather variability, such as droughts, floods, and related storm events, that accompany climate change.2 In the case of commercial crops particularly, the exceeding temperature thresholds and water availability are likely to be the main contributors to crop failure or diminished quality of the crops.2
Exposure and Vulnerability
Plant and livestock processes are impaired with increasing temperatures and higher frequency of extreme weather events.
- Temperature thresholds exceeded
- Water availability
- Soil quality
- Competition for resources (abundance of weeds)
Crops have traditionally been grown in regions that have natural climate conditions that support any particular planted crop. However, warming global temperatures could change that. Crop temperature thresholds are extremely sensitive to the change in degrees as well as the timing of the temperature swings, which is why unpredictable climate variability can be devastating to yields.3 The crop lifecycle stages from seedling, to juvenile, to mature, to reproduction, prefer certain temperatures that allow growth to excel. Beyond a certain point, increasing temperatures adversely cause crops to complete their lifecycle development sooner than is habitually required, producing not only smaller yields but also impairing the quality of the harvest.4 Depending on the region, extreme weather events will play an important role in determining the water availability and soil quality. Not enough water leads to drought and plants drying out whereas too much water saturates the soil and causes mass degradation and erosion. Another emerging pressure on crops will be the abundance of weed species. An increase in coverage of weed species is expected to siphon resources from the planted crops and act as a stressor to crop growth.5 Not only will the occurrence of more weeds impact crop growth, but they will put strain on the farmers themselves. Weed control costs already push $11 billion US and that spending is expected to increase with rising temperature and carbon dioxide levels.6
The United States Department of Agriculture outlines four primary impacts that changing climate conditions will have on animal agriculture:
1) Feed-grain production, availability and price
2) Pastures and forage crop production and quality
3) Animal health, growth, and reproduction
4) Disease and pest distribution7
Similarly to crops, livestock have sensitive temperature thresholds. Temperatures in excess of 2-3° Celsius of regularly maintained body temperature yields diminished performance, productivity, and fertility.7 Temperatures anywhere in the 5-7° Celsius range above normal homeostasis often result in livestock death.7 This heat stress will ultimately begin to have an impact on livestock and lead to poor returns for the production of meat, milk, and eggs. It is also expected that warmer and humid conditions will promote the prevalence of insect and disease which can overall diminish the health of livestock.7
Adaptation and Resilience
Diversifying Crop Rotations and Cultivar Selection: Although more difficult on the commercial scale, diversifying crop rotation is an effective method to increase pest resistance and improve soil quality. By consistently rotating crops and breeding only the healthiest year after year, crops will lead to strong yield returns in the future.7
Development of Heat, Cold, and Pest Tolerant Crops: Seeds with the ability to increase resistance to heat, cold, and pests, accompanied by these other techniques will improve the ability of farmers to cope with increasing frequencies of temperature and weather variability.7
Crop Insurance: Buying crop insurance is not a highly effective way to improving resilience and adaptation but it can be reassuring to some farmers who have fears of losing their entire crop when their livelihoods depending on it.7
Sustainable Farming Methods: Many of the negative impacts of climate change on the agricultural industry can be mitigated or combated by practicing sustainable farming techniques, many of which have been around for a long time and retained in traditional knowledge forms. These techniques focus on improving the quality of the land by rotating/diversifying crops, planting cover crops, reducing tillage in order to cease the loss of nutrients, and the integration of livestock and crops together.7
Although we are already seeing some of these impacts on crops and livestock today, thankfully for the agricultural industry, these climate conditions that cause loss of crops and livestock production do not happen immediately and there is still time to implement strategies to prevent catastrophic losses in the future. Agriculture has been adapting for millennia and current climate conditions will be the next test for the industry.
Strategies for enhancing crop adaptation and resilience
- Timing of field operations
- Improved technology
- Diversifying crop rotations and Cultivar Selection
- Development of heat, cold, and pest tolerant crops
- Crop insurance
- Sustainable farming methods
Timing of Field Operations: Simply altering the timing of planting seasons and the application of fertilizers and pesticides can protect yields. As temperatures continue to increase, depending on the crop itself, the planting season can begin earlier as early spring temperatures will be warm enough and this will hopefully help avoid the number of extremely hot summer days that would normally effect the crop.7
Improved Technology: Improved technology can benefit in a number of ways, although often requiring more energy intensive practices and increases greenhouse gas emissions. Updating facilities with cooling mechanisms can reduce the heat stress experienced by livestock. Improved irrigation systems make efficient use of the water and provide full coverage to the fields. Advanced fertilizers, herbicides, and pesticides will all contribute to supplementing crop growth. Organization and land use management will be necessary to getting the most out of the growing season.7
1 Jerry Melillo, Terese Richmond, and Gary Yohe, Highlights of Climate Change Impacts in the United States: The Third National Climate Assessment, (U.S. Global Change Research Program, 2014).
2 Patricia Romero-Lankao et al., Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part B: Regional Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge: Cambridge University Press, 2014), 1462.
3 S.C. Pryor, Climate Change in the Midwest: Impacts, Risks, Vulnerability, and Adaptation (Bloomington, 2013).
4 C.L. Waltham et al., Climate Change and Agriculture in the United States: Effects and Adaptation, (Washington DC, USDA Technical Bulletin 1935, 2013).
5 Jerry Melillo, Terese Richmond, and Gary Yohe, Highlights of Climate Change Impacts in the United States: The Third National Climate Assessment, (U.S. Global Change Research Program, 2014).
6 Climate Change and Agriculture in the United States: Effects and Adaptations. Retrieved from https://www.usda.gov/oce/climate_change/effects_2012/effects_agriculture.htm
7 C.L. Waltham et al., Climate Change and Agriculture in the United States: Effects and Adaptation, (Washington DC, USDA Technical Bulletin 1935, 2013).
University of Missouri Extension
San Antonio Express
Nature's Garden Express
Montgomery County Conservation District
United States Department of Agriculture