Energy > Climate Change
The impact of climate change on world agriculture
This article is part of our series focused on the causes and consequences of a warming planet.
Changing precipitation patterns, rising temperatures, and more extreme weather events will negatively impact the world’s ability to produce food. At the same time, demand for food will grow due to an increasing world population and rising incomes in the developing world. Meeting this challenge will depend on agriculture’s ability to adapt to a changing climate while developing and adopting the technologies needed to meet the increase in food demand.
World food production relies on regions of the world highly suitable for rain fed agriculture, as shown in Figure 1. These regions of the world include the Midwest United States, portions of Brazil and Argentina, Europe, sub-Saharan Africa, India, portions of Australia, and Eastern China.
A combination of four factors make these regions suitable for productive agriculture. These factors are:
- Temperature levels for optimum reproduction and plant growth,
- Precipitation amounts for maximum production
- Soils suitable for agricultural production, and
- Terrain suitable for modern agricultural production practices.
The areas of the world that have suitable soils and terrain are stationary and do not move.
However, precipitation patterns may change due to the changing climate. Current productive regions of good soils and adequate terrain may become too dry or too wet for optimum agricultural production.
Moreover, the warming of the planet will impact agricultural production. A small rise in temperatures in many prime growing regions may slightly increase yields, but more significant temperature rises will lead to yield declines.
So, these altered precipitation patterns and temperatures may no longer match up with regions of productive soils and adequate terrain.
Regions of the earth in the mid to upper latitudes may benefit from more heat and a longer growing season, such as those in Canada and Russia. But regions at lower latitudes are especially vulnerable because they already suffer from intense heat. This loss is expected to more than offset any advantage in the upper latitudes.
An example of this is research indicating the Corn Belt is moving north due to warmer and longer growing seasons. Conversely, current regions of the Corn Belt may become too hot for optimum corn production.
Role of irrigation
Less precipitation in an area due to climate change will usually lead to a decrease in productivity. An example is droughts. However, receiving more precipitation may not improve agriculture productivity. If the increase in precipitation leads to more water-logged soils and flooding, productivity will decline.
Irrigation can provide a short-term solution to areas with declining rainfall but often does not provide a permanent or sustainable solution. There are numerous regions of the world where widespread irrigation faces challenges relating to water supply (e.g., aquifer depletion, declining river flow, competing uses for reservoir water) or salinization of land under long-term irrigation. Numerous past civilizations which thrived and expanded based on irrigated agriculture eventually collapsed because of irrigation’s long-term unsustainability.
The sustainability of irrigation is of special concern where water from underground aquifers is used. Over half of the world’s largest aquifers are being drained faster than they are being refilled. In addition, drained aquifers can rest in the collapse of the aquifer cavern so it can never be refilled.
We know that climate change will have a significant impact on the world’s agriculture. So, we need to focus on the areas of the world that we suspect will be negatively impacted and develop strategies for adapting to these changes. These strategies must focus on agricultural research and development, including investment in new technologies that can reduce the impact of climate change and help offset the negative impacts of a changing climate.
Because of the global nature of agricultural markets, shifting global agricultural production patterns will impact world markets for grains and other agricultural products. Due to this, US farmers must address both the impact of climate change on their own operations but also respond to these changing market signals.
See the Ag Decision Maker website for more from this series.
Don Hofstrand, retired extension agricultural business specialist, firstname.lastname@example.org
Reviewed by Dr. Eugene Takle, retired professor emeritus Iowa State University