Climate change is already affecting our lives in the Inland Northwest, especially in one of our largest economic sectors: agriculture.
We already see warmer temperatures, wetter winters, and different precipitation patterns. Overall, by the end of the century Inland Northwest temperatures are expected to increase between 5oF and 9oF and precipitation is expected to increase between 4.5 and 8.6%, resulting in still wetter winters and hotter, drier summers.
Wheat crops will be affected by warmer, drier summers and wetter winters.
Although the winter moisture will have some benefits, they will not offset the severe negatives of summer heat and drought. Some watersheds in the region will experience increased drought frequency and severity. There will be a decline in water available for irrigation and an increase in water stress on plants and animals. Extreme weather events (leading to such things as flooding, erosion, and runoff) are expected to reduce crop yields and livestock productivity.
The value of apple crops will be affected by water supply problems.
Apples and cherries are relatively water-intensive crops. Because of problems with water supply, the value of those crops in the Yakima Basin is expected to decline by about 5% by the 2020s. Some nuts and fruits need chilling to properly develop, e.g., wine grapes.
Warming and changing rainfall patters may have adverse impacts on the quality of our wheat and potatoes. Washington State University is tracking this problem as it affects wheat and developing strategies. New invasive species may attack the region’s crops. Pressures from pests, weeds, and pathogens are likely to increase. We expect to see increased populations of the codling moth, which attacks apples, and the tuber moth, which attacks potatoes. The same is true of the cereal leaf beetle. Changes in the timing of warming in the Spring may affect the timing of flowering reducing the number of pollinators at a crucial time.
Wine grape quality is affected by overnight chilling.
Livestock impacts derive from heat stress, impacts on their food sources and decreased digestibility of rangeland grasses. Reductions in available water in the late summer will also negatively impact forage growth.
On the potentially positive side, farming and ranching are flexible industries. Inland Northwest dryland cereals may benefit from increased CO2 fertilization and more efficient water use. Winter wheat yields are expected to increase and spring wheat yields are expected to stay about the same. Warmer temperatures may allow some crops that are sensitive to cold temperatures to be grown in the area.
However, the net result of climate change will be greater challenges for farmers, along with impacts in the supporting industries such as food processing, freezer storing facilities, and the distribution industry.
Possible mitigation measures include reducing irrigation water demand. There are also a variety of ways to increase soil carbon storage. Farmers could reduce tillage and/or burning. They could also increase their use of manures, biosolids, composts, etc., putting more carbon in the soil. Of course, some of these options come with risky side-effects.
All in all, the main thing to understand about the impacts of climate change on Inland Northwest agriculture is that things will not be the same. It will take time, vigilance and determination to adjust to the changes as we transition into a new normal. As climate change progresses, our farms will not successfully operate the same way our grandfathers’ farms did.