How Does Climate Change Affect Crop Production?

The ways that humanity has been producing food have been developed under fairly stable climate conditions. However, with a warming world, we will see many different changes to the established agricultural system. With all of the changes that are likely to happen to our planet as average global temperatures increase due to climate change, agriculture will be affected in many different ways around the world.

This will be especially the case in developing countries that have limited financial resources and technologies available to adapt to such environmental impacts.

Some of these impacts are already being seen today but may become much worse if we continue down a path of “business as usual” with our consumption of fossil fuels and natural resources.

Impacts of climate change on global crop production

Some of the predicted climate change impacts on agriculture around the world include:

• Changes in rainfall patterns, leading to drought, water shortages for irrigation, and flooding.
• Extreme weather events such as hurricanes, heavy precipitation events, and droughts that negatively impact agricultural production.
• Rising temperatures, leading to shifts in growing seasons and higher occurrence of pests and diseases.
• Increased average temperatures and drought in areas that are already barren and devastated.
• Decreased production of traditional crops, as their survival threshold is surpassed due to high temperatures.
• Glacial melting, leading to flooding and soil erosion.
• Reductions in food availability, food accessibility, and food supply stability.

Let’s have a more detailed look at how these some impacts might affect the global agricultural production.

#1 Shifts in precipitation patterns, leading to increased droughts and flooding

As the planet warms, precipitation is predicted to increase at higher latitudes and decrease in the tropics and the subtropics [1].

In many places, drought is already becoming the norm, dramatically reducing water availability for crops, and increasing irrigation requirements. In existing arid regions, it may be difficult to adapt the cultivation of crops to even more drought and increased temperatures.

In areas experiencing an increased number of downpours, increased flooding can wipe out an entire crop with a single storm event.

#2 Water runoff and soil erosion

With increased precipitation and downpours, it can be difficult to store the excess runoff water volumes in the ground that would otherwise be used for crops. This excess water runoff also erodes precious topsoil that is needed for growing crops.

#3 Increased pests and disease

In a warmer world, there is likely to be an increased vulnerability of some crops to problems like fungal diseases and insect pests that will stick around longer during a longer growing season [2].

#4 Shifting of growing regions further north & longer and more frequent heat waves

It has been found that hardiness zones have been shifting further northward in the Northern Hemisphere during the last several decades as temperatures have increased [3]. The incidents of heatwaves each summer is also increasing globally [4].

The shifting of hardiness zones will likely mean that crops that have always been grown in a given region may no longer be able to grow well there in the future with warmer temperatures.  However, such crops may still grow well in areas further north where it is cooler [5].

#5 An increase in extreme weather events

An increase in extreme weather events such as strong tropical storms and tornadoes, may destroy crops much more frequently [6].

#6 Changes in the growing seasons

Although an extension in the growing season due to an earlier spring and a later fall might increase the productivity of some crops, the increased opportunities for droughts, floods, storms, diseases, and insects due to climate change could override some of these potential gains in productivity of a longer growing season.

#7 Decrease in food security

In existing arid and tropical regions, increased temperatures, heat stress, and increased water loss through evaporation may make growing crops using traditional methods even more challenging.

#8 Flooding of agricultural fields along low-lying areas

Due to an increase in sea levels, low lying coastal agricultural areas are expected to experience more flooding.

As sea levels continue to rise, groundwater supplies that are used for agriculture may become increasingly salinated and unsuitable for agriculture [7].

#9 Melting glaciers

As average temperatures continue to increase, there will be an increase in water flow from melting glaciers around the world, potentially leading to the flooding of agricultural areas near glacier-fed rivers.

Once glaciers have significantly retreated, populations that depend upon glacier-fed waters are likely to experience decreased water flow and drought, leading to negative impacts on agricultural productivity [8].

Impacts of climate change on agriculture in developing countries

Climate change is especially a threat to the global goals of sustainable development and eliminating poverty around the world.

Because many of the agricultural systems in developing countries are already under stress today due to land and water resource degradation, climate change and its associated extreme weather events are likely to make such agricultural problems even worse.

Some effects of climate change on agriculture in Africa

• Many areas in Africa already have extremely variable climates, and flood and drought events can occur in the same area within a few months of each other. Increased climate variability and an increase in the frequency and severity of extreme weather events will lead to an increased risk of drought and flooding.
• One-third of the African population, 220 million people, lives in drought-prone areas. Much of the land is already undergoing desertification and other forms of land degradation. Dust and sandstorms already negatively impact agriculture in the Sahara and Sahel.
• Rainfed irrigation, the major water source for agricultural production in Africa, will be strained as variability of rainfall and drought increases on the continent. This will especially be problematic for subsistence farmers and in sub-Saharan Africa.
• Regions along Africa’s coastlines risk inundation of seawater due to sea level rise, negatively impacting agriculture in those areas.
• An increase in water scarcity with great potential for conflicts. Nearly all of Africa’s rivers run along the boundaries of more than one country.
• There is predicted to be a large loss in African agricultural land, as well as shorter growing seasons and lower yields.
• Africa will likely experience a decline in many subsistence crops, including sorghum, maize, millet, and ground nuts, increasing food insecurity and the risk of hunger [9].

Predicted climate change impacts on crops in Asia

• Land and ecosystems in Asia are already being generally degraded, and are predicted to be at a higher risk with climate change impacts.
• Increased risk of extreme weather events such as heat waves, tropical cyclones, drought, intense rainfall, tornadoes, snow avalanches, floods, thunderstorms and dust storms could all have impacts on agricultural productivity.
• Reduction in crop yields in many regions increases the risk of hunger for millions of people.
• Reduction in soil moisture and evapotranspiration may lead to degradation and desertification of the land.
• Some northern areas may experience an increase in crop productivity [9].

Climate change effects on agricultural productivity in Latin America

• Torrential rain events, tropical cyclones, and floods are expected to negatively affect agricultural land.
• Arid and semi-arid areas will receive less rain, reducing the viability of agricultural land there.
• Agricultural yields are predicted to decrease throughout the region by the year 2100, although some areas may experience increased yields.
• Approximately half of agricultural land is predicted to experience deforestation and salinization by the 2050’s.
• Food insecurity is expected to increase in dry area agricultural lands where salinization and erosion will likely occur, reducing yields and livestock productivity [9].

Possible impacts of climate change on crop productivity in the small island developing states

• Comprised of 51 states and territories throughout the Pacific, Indian, and Atlantic Oceans and the Caribbean Sea. Sea level rise is currently placing very valuable arable land and water resources at risk due to inundation and soil salinization, and such impacts are expected to increase as global temperatures increase.
• Extended periods of drought, a loss in soil fertility, and a reduced growing season. These effects are predicted to result in great economic losses and increase food insecurity.
• Extreme weather events will negatively impact agricultural production throughout the region [9].

The challenges that we face for agricultural production in developing countries due to climate change are many. A failure to adequately address climate change holistically as global community will result in the devastation of large portions of the Earth’s land as well as its people, leading to an increase in food insecurity for many.

Both climate change mitigation and climate change adaptation approaches for agricultural production, such as through the use of permaculture design, must be taken into account to sustainably feed the human race in a warmer world.

Possible areas of agricultural adaptation to climate change

In a warmer world, farmers will likely need to change the varieties of crops that they grow, as well as their farming methods.

Some possible agricultural adaptations to climate change include:

• Growing heat-sensitive crops further north in the Northern Hemisphere and further south in the Southern Hemisphere in cooler regions.
• Growing more heat-tolerant crops and more perennial crops such as through the application of permaculture.
• The reduction or elimination of water-thirsty crops, such as rice.
• An increase in the use of water conservation methods such as drip irrigation.
• A dramatic reduction or elimination of fossil fuel use in agriculture, as agriculture is currently a large user of fossil fuels, which contributes to climate change.
• The localization of food systems and the growing of food indoors to increase agricultural resilience in the face of a changing and unpredictable climate.
• Despite the many agricultural challenges that we are facing in a warmer world, we have a tremendous opportunity to transform our food system into a much more sustainable world and if we act swiftly and decisively today, we may be able to avoid the worst of the predicted climate change impacts on agriculture in the future.

Despite the many agricultural challenges that we are facing in a warmer world, we have a tremendous opportunity to transform our food system into a much more sustainable world and if we act swiftly and decisively today, we may be able to avoid the worst of the predicted climate change impacts on agriculture in the future.