Agriculture is a major contributor to global climate change and is potentially one of the most vulnerable sectors of the global economy. Climate change not only has direct impacts on crop growth, but can also indirectly impact the sector through higher input prices, increased pest and disease pressure, increased soil erosion and changes in water availability.
In the US, agricultural production accounts for approximately 10% of the nation’s greenhouse gas emissions. This includes CO2 and CH4 produced as a result of burning fossil fuels for fertilizer and machinery, depositing animal manure on the land, and plowing and tilling the soil; while agriculture sequesters carbon by producing organic matter and soil carbon through photosynthesis and the conversion of energy into biomass.
Climate change can have direct impacts on crop yields by increasing or decreasing temperature, precipitation, and soil moisture levels. Warmer temperatures can significantly reduce grain yields and are expected to shorten the grain production season. Increasing temperatures also increase the risk of pests, diseases and weeds; while changes in precipitation patterns can change the timing of crop harvests, leading to imbalances in supply and demand.
Water Availability and Soil Quality
Rising temperatures can lead to increased evapotranspiration, reducing soil moisture and in turn, water availability for crop production. Rising temperatures may also lead to the decline in soil quality, leading to reduced fertility and yields.
Increasing temperatures and changes in precipitation patterns are expected to affect nutrient cycling in two ways. First, increased evapotranspiration may reduce nutrient availability, as water that has removed nutrients from the soil does not return. Secondly, increases in extreme weather events can decrease nutrient recycling, as rain and floods may wash away agrochemicals, adding to pollution in rivers and lakes.
Crop Quality and Composition
Rising temperatures and changing precipitation patterns could also have an effect on crop composition and quality, leading to a decrease in food quality, or lack of desired nutraceuticals or vitamins in food. Higher temperatures also increase the risk of heat stress, leading to reduced producer yields.
Agricultural production can impact the environment in positive and negative ways. Ecosystem services, such as soil erosion control, water purification, pest control and carbon mitigation, can be supplied by agriculture production. However, if these services are not managed properly, they can lead to soil degradation, water pollution, loss of biodiversity and climate change.
Climate Change Strategies
Agriculture has the potential to reduce emissions while protecting and promoting ecosystem services. Climate strategies such as sustainable intensive farming and integrated pest management help increase yields while reducing energy inputs and emissions. Soil conservation practices such as no-till farming, agroforestry and cover cropping, help reduce soil erosion and nutrient losses, increase organic matter in soils and sequester carbon.
In addition to these approaches, governments and farmers can implement climate change adaptation strategies to reduce the impacts of climate change on agricultural production. These strategies could include the development of heat-tolerant crop varieties, shifts from annually-planted crops to perennials, the expansion of water storage and irrigation infrastructure, the adoption of precision farming and conservation agriculture, the adoption of conservation measures such as agroforestry, and the monitoring and management of pests and diseases.
Agriculture production is highly sensitive to changes in climate and can be both negatively and positively impacted. Smart strategies and innovative technologies are essential to help farmers mitigate climate impacts on agriculture and ensure sustainable production in the face of climate change.