In the United States, specialty crops were originally defined more or less by default--they were non-row crops that were not covered by U.S. farm support programs. A more specific definition did not come until 2004, as part of the Specialty Crops Competitiveness Act, which explicitly defines them as “fruits and vegetables, tree nuts, dried fruits and horticulture and nursery crops, including floriculture”. In recent farm bills, Congress has established a number of programs that target some particular needs of the specialty crop sector, but producers of these crops have deliberately chosen not to seek programs that provide direct financial support such as has been the norm for producers of major crops such as corn, wheat, and cotton since the first farm bill passed in 1933 at the height of the Great Depression.
According to data collected by USDA’s Economic Research Service, market receipts for U.S. specialty crops are projected at $85.9 billion in 2020, accounting for 24 percent of the value of all agricultural production this year. The majority of specialty crops are raised in states with mild climates amenable to year-round production, such as California, Florida, Oregon, and Washington state, which are expected to account for nearly 60 percent of production by value this year.
In general, specialty crops are seen as more sensitive to climatic stressors such as increasingly variable weather and climate change. They also typically require more comprehensive management compared to traditional row crops. In addition, many regions in which specialty crops are the dominant agricultural activity rely heavily on irrigation to succeed financially, which makes their portion of total production more vulnerable to problems of water scarcity that are being aggravated by recent bouts with multi-year droughts on the West Coast.
Climate change is expected to impact growing conditions for specialty crops in several different ways, some of which have already been felt by producers around the country. With respect to higher average temperatures, if a credible global effort to reduce greenhouse gas emissions does not emerge, climate change models indicate that average global temperatures could increase by 4◦ C (7.2◦ F) by 2100. Many annual crops, including most types of vegetables, have specific temperature tolerances under which they can thrive, and many of their threshold temperatures will be exceeded under this scenario in current growing regions, especially later in the 21st century.
Some of these impacts are already adversely affecting specialty crop production in parts of the country. For example, crops that break dormancy too early under so-called ‘False Spring’ conditions are at risk for freeze and frost damage. Tree fruits, including apples, cherries, and peaches are especially vulnerable to these spring freeze events. In 2012, Michigan farmers alone lost 90 percent of their tart cherry crop due to warm March temperatures and subsequent freezes in April.
In California, crops like pistachios, peaches, and almonds need a certain amount of cold weather every year, a requirement the industry refers to as ‘chill hours’. The problem is that in recent decades, there has been a decrease in the availability of hours within the proper temperature range needed for tree crops to mature properly. Multiple University of California studies predict that within 30 to 50 years it may be too warm to grow many tree crops where they now flourish.
Research shows that changes in climate that create warmer, drier conditions, increased drought, and a longer fire season are boosting the risk of severe wildfires. For much of the U.S. West, studies suggest that an average annual 1 degree C temperature increase would increase the median burned area per year as much as 600 percent in some types of forests. In California alone, it is estimated by the state’s Department of Forestry and Fire Protection that wildfires through early October of this year had burned more than 4 million acres, a level that is double the previous high dating back to 1987. Most of that land is forested, but some crops, such as horticultural crops along the coast, were affected by the combination of extreme heat and fires. Wildfires damaged or destroyed property in several vineyards in the Napa and Sonoma Valleys. In addition, smoke from those fires affected the quality of grapes growing in other vineyards adjacent to fire zones. It is anticipated that “smoke taint” that has been absorbed into at least some of those grapes will render them largely unusable for wine production. The overall impact on the 2020 California wine crop will depend largely on what stage in the growing process individual fields were exposed to the smoke.
Higher temperatures and increased variability of precipitation would, in general, lead to an increased irrigation water demand, even if the total precipitation during the growing season remains the same. Different climate models project different worldwide changes in net irrigation requirements, ranging from 2 percent to 7 percent by the 2070s. Within the Western United States, the availability of surface water for irrigation purposes relies heavily on melt water from snowpack accumulated in the various mountain ranges in the region. Current climate-change projections suggest that, by the middle of the 21st century, at a least a third of this storage in springtime snowpacks will be lost due to the increase in winter temperatures.
The multiple impacts on specialty crops anticipated from climate change, some of which are described above, are likely important factors in the decision by the state of California to take its own steps to combat climate change, even in the face of little or even no actions at the federal level. In 2013, the state of California launched a carbon cap and trade program to help reduce emissions of GHGs below 1990 levels by 2020, and 80 percent below 1990 levels by 2050. Under this program, large-scale industrial facilities such as power plants and fuel distributors are required to obtain emission allowances and cap their emissions, but those companies can also comply by obtaining offsets through the carbon trading market.
