Rangelands encompass over 770 million acres of land in the U.S., and despite their classification as a single land type, these U.S. rangelands occur across a variety of ecosystems and have unique vulnerabilities. There is consensus in the scientific community that rangelands are especially vulnerable to the effects of climate change, and that management will have to be adjusted in response to these changes, according to the University of Wyoming College of Agriculture and Natural Resources Extension.
We lack precise understanding of how climate change will impact the management of ecological systems, but adaptive management can help ranchers adjust to changing environmental conditions, reduce vulnerability to worst-case outcomes, and increase resilience to climate change.
Rangeland managers have a persistent need to consider how to adapt to the impacts of climate change on rangeland systems. Adaptation can encompass changes to processes, practices and structures to moderate potential damages or take advantage of opportunities and adjustments to reduce vulnerability of communities, regions or activities, such as livestock production. While climate change is global in scale, these adaptive strategies will need to be local or regional in nature.
Addressing uncertainty around climate change impacts on rangelands will require flexible management strategies, regular monitoring and practices/policies that allow managers to adapt as new knowledge is gained.
Temperature is a critical driver of atmospheric phenomena, so global changes in temperature are also altering precipitation patterns. In general, a warmer atmosphere tends to be more dynamic, with an increased frequency of severe storms and precipitation delivered in larger events. How these severe events will develop across the U.S. is likely to vary more than projections for warming. Overall, annual precipitation amounts are expected to increase in the north and decrease in the south. The transition zone between areas of increased
and decreased precipitation will move depending on the season. During winter, that zone stretches from approximately southern California to South Carolina. In summer, that zone pushes north into Canada. The southern Great Plains and Pacific Northwest are projected to receive less precipitation, while winter and spring will be wetter or drier, depending on latitude.
Let’s look at some specific changes impacting three key rangeland regions.
The grazing of livestock in the Southwest region over the past 200 years has had a significant impact on vegetation, causing major shifts in species abundance and considerable degradation. Today, many land managers in the Southwest suggest rangeland degradation and experience with drought are two factors that have instilled in them a more conservative management strategy, aiming to enhance resource resilience rather than maximizing stocking rates or even profit.
The Great Plains region comprises one of the largest native grasslands in the world. Although urbanization is increasingly encroached upon it, 80 percent of the land area remains in agriculture, with over half of this area classified as rangelands and pasture.
Over the past few decades, average temperatures have increased in this region, with fewer cold days, more hot days and increased precipitation over most of the area.
Annual precipitation is expected to increase in the northern Great Plains and decrease in the southern Great Plains. Extreme events, such as drought, heat waves and intense precipitation events are predicted to become more common.
The humid, subtropical climate and abundant rainfall of rangelands in the southeastern U.S. distinguish them from the desert or semi-arid rangelands of the West. Two notable rangeland areas are the Texas Coastal Prairie and the dry prairies and flatwoods of central and south Florida.
Projections for the end of the 21st century suggest 4 degrees F to 8 degrees F of warming, with slightly larger increases for interior parts of the region. The number of days above 95 degrees F is projected to increase substantially. By the end of the century, north Florida is projected to have approximately six months of temperatures above 90 degrees F.
Learn more on how changing weather patterns are affecting individual ranch operations in each region in the Critical Operational Concerns From Climate Change fact sheet.