California Department Of Food Agriculture

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California Department Of Food Agriculture

Transcript Of California Department Of Food Agriculture

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CALIFORNIA DEPARTMENT OF FOOD & AGRICULTURE

2013

Climate Change Consortium for Specialty Crops: Impacts and Strategies for Resilience
Photo courtesy of Jocelyn Gretz, Rio Farms
California Department of Food and Agriculture

Contents
Executive Summary....................................................................................................................................... 3 Chapter 1: Introduction ................................................................................................................................ 5 Chapter 2: Temperature ............................................................................................................................. 10
Introduction ............................................................................................................................................ 10 Temperature Sensitivity of Crops ........................................................................................................... 11 Adaptation Strategies ............................................................................................................................. 14 Chapter 3: Water Resources ....................................................................................................................... 17 Introduction ............................................................................................................................................ 17 Drought ................................................................................................................................................... 22 Flooding................................................................................................................................................... 23 Adaptation Strategies ............................................................................................................................. 24 Chapter 4: Increased Pests and Impacts on Pollination ............................................................................. 30 Introduction ............................................................................................................................................ 30 Invasive Species ...................................................................................................................................... 30 Increased Pest Pressures ........................................................................................................................ 31 Impacts on Pollination ............................................................................................................................ 35 Adaptation Strategies ............................................................................................................................. 38 Chapter 5: Additional Recommendations................................................................................................... 42 Summary of Recommendations.................................................................................................................. 48 Acknowledgements..................................................................................................................................... 62 References: ................................................................................................................................................. 64

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Executive Summary

The California Department of Food and Agriculture (CDFA) convened the Climate Change Consortium, a diverse group of individuals involved in California specialty crop agriculture, to identify specific climate change adaptation strategies for growers. Changes to the climate as a result of anthropogenic activities are well recognized and acknowledged by the scientific community. Therefore the Consortium assumed, as charged by CDFA, that climate change is now occurring and will continue to occur in the future. The realities of climate change were not debated, nor were mitigation measures identified although, some adaptation measures could also be also considered mitigation measures.

The Consortium was asked to evaluate

climate change impacts and to propose

potential strategies for adaptation so that California agriculture and CDFA can prepare for impacts. The Consortium discussed and documented challenges faced by growers due to climate change.

“As we head into another summer with less than 20 percent of normal snowpack in the
Sierra-the lifeblood of Central Valley agriculture- we worry about the future”

The Consortium addressed climate change impacts to temperature, water resources, pests and pollination. Growers

-Ward Burroughs, Merced County farmer; Modesto Bee opinion page June 6, 2013

will face new challenges from changed

environmental averages, trends,

variability, and extremes. These challenges are summarized below. While specialty crops are the focus

of this report, the Consortium’s work on climate change impacts can be applied widely to California

agriculture.

Challenges:
• Increased average, minimum, and maximum temperatures in all seasons • More frequent and longer-lasting heat waves in the summer • Reduced number of winter chill hours and fog • Uncertainty in temperature change projections and forecasts • High spatial variability of climate change and impacts of climate change • Reduced precipitation (drought), increased precipitation (floods), and more variable
precipitation and snowpack accumulation • Decreased winter snowpack, earlier timing of snowmelt and spring river runoff, and reduced
spring runoff • Altered reservoir storage regimes • Reduced natural groundwater recharge • Reduced water quality due to reduced fresh water supplies • Complex and unpredictable alterations to plant, pest, and pollinator abundance and spatial
distributions • Altered inter-species dynamics in agricultural ecosystems • Reduced effectiveness of managed pollinators • Vulnerability to pest and pollinator changes

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The Consortium discussed creative solutions to be investigated and implemented at the level of individual growers; local communities, cities, and counties; and through regional and state planning processes. There was a general consensus within the Consortium that growers are managing their lands in consideration of dynamic environmental and agronomic variables and therefore, existing efforts can contribute to adapting to climate change impacts. However, for specialty crop agriculture in California to adapt and be prepared for climate change events, growers require agricultural support services, scientific answers to fundamental climate change impact questions, investment in planning and preparedness, and technological innovations. These requirements were categorized and prioritized under the categories of Outreach and Education, Planning and Resource Optimization, Research Needs, and Technology and Innovation. Listed below are some of the leading recommendations identified by the Consortium.
Leading Recommendations for CDFA:
1. Support economic and environmental studies of the costs, benefits, and risks of adaptation strategies
2. Facilitate a reinvestment in grower technical assistance and trainings specific to climate change adaptation, such as for water, soil, and pest management
3. Advocate for inclusion of grower interests in the Integrated Regional Water Management (IRWM) process
4. Perform or fund a review of regulatory barriers to adaptation mechanisms, such as food safety and other regulations
5. Facilitate interagency coordination on the recommendations of the Climate Change Consortium
6. Compile a list of grower needs for weather data and forecast products 7. Develop research plots to study adaptation strategies and new technologies and products 8. Promote farmland conservation 9. Recognize growers who develop or adopt novel strategies to adapt to climate change 10. Support USDA NRCS in a review and/or creation of policies to improve growers’ ability to
adapt to climate change
This report is a synthesis and summary of scientific information shared by experts in and outside of California who are working on climate change at the interface of agriculture, information from discussion that ensued in the Consortium meetings, and recommendations proposed by the Consortium. The purpose of this document is two-fold: one is to provide growers, agricultural associations, specialty crop commodity groups, the general public, state agencies, and other agricultural stakeholders with examples of climate change impacts and potential adaptation strategies, specifically as they relate to agriculture in California. Second, the document lists adaptation recommendations (beginning on page 48) that the Consortium developed, providing CDFA direction on future climate change activities.

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Chapter 1: Introduction
California is the nation’s leading agricultural state in gross cash receipts; $43.5 billion in 2011. A large portion of the crops grown in the state are “specialty crops.” Specialty crops are defined as fruits and vegetables, tree nuts, dried fruits, horticulture, and nursery crops including floriculture. In 2011, global exports of California’s specialty crops reached nearly $10.9 billion. California is the United States’ sole producer of several crops such as Clingstone peaches, olives, pistachios, walnuts, almonds and artichokes (California Department of Food and Agriculture 2013a). The state’s unique environmental zones and Mediterranean climate allow for a diversity of crops to be produced throughout the year for local, national, and global distribution. California’s specialty crop commodities are known for being a healthy, affordable, safe food source.
Impacts to agriculture from changes in weather will be felt differently in different parts of California. Temperature, rainfall, humidity, and wind are some common weather variables. Long-term patterns of weather are referred to as the “climate,” and changes in weather patterns over time are defined as “climate change.” Climate is essentially the average pattern of weather for a region, which could be a county, state, continent, or the entire world. Climate change occurs when an area’s weather pattern, as indicated by weather variables, deviates significantly from the “average,” or from the historically observed “normal.”
Due to the many human and environmental factors influencing climate change, and due to increased variability in weather over time and across space, climate change effects are difficult to predict for a specific agricultural operation. Nevertheless, rigorous analysis of California weather data shows that climate change is already occurring in some parts of the state. Future climate trends have been predicted for California. California can expect to see increased average and more extreme temperatures; altered rainfall, snowpack accumulation, and snowmelt timing regimes; increased variability in both temperature and rainfall; and increased and more variable durations and frequencies of heat waves, droughts, and floods.
Temperature changes are generally used as an indicator for climate change. Below are several temperature-based examples of climate change provided to highlight the climate change effects at the global and local scales.
Climate change is well documented at the global scale. It has been demonstrated through many scientific studies and global data collection that anthropogenic activities have contributed to historically high greenhouse gas levels in the atmosphere. Consequently, there has been a global increase in average temperatures. This process of greenhouse gas induced temperature increase is known as “global warming”(Houghton & IPCC Working Group I 2001). The increase in greenhouse gases (specifically carbon dioxide) and temperatures are provided in Figure 1. Figure 1 shows increased temperatures corresponding closely with increase carbon dioxide concentrations over the last 150 years.

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Figure 1: Ten-year moving average of global temperatures between 1750-2000 (black) and temperature predicted by CO2 and volcanic emissions (red). The large negative extremes in the early temperature records are likely explained by volcanic activity; the upward trend in the recent record is an indication of anthropogenic change. This demonstrates the strong relationship between CO2 concentrations and global warming. The grey area is the 95% confidence interval. From Berkeley Earth Surface Temperature.
Similarly, Figure 2 below shows that California has seen similar, more recent evidence of increased temperatures. Investigation and prediction of climate change in California is still an active area of research, but experts agree there has been, and will continue be changes in regional and statewide weather patterns stemming from climate change. Scientists anticipate an acceleration of warming across the western United States (Moser et al. 2009). California should see between a 1° F and 3° F increase in average daily temperature by 2050, and between a 2° F and 6° F increase by 2100a (Lobell et al. 2006; Cayan et al. 2008; Nakićenović et al. 2000). California is expected to experience increases in average temperatures in all seasons, and greater warming in the summer than in the winter (Cayan et al. 2008). Specific climate change impacts to human and environmental health (in addition to agriculture) have been documented in California (OEHHA 2013).

a These estimates are generated by a model known as a coupled ocean-atmosphere general circulation model (GCM) run using climate scenarios developed by the Intergovernmental Panel on Climate Change (IPCC) of low- to high-emissions trajectories (Nakićenović et al., 2000). The IPCC is a scientific intergovernmental body formed by the United Nations to provide scientific assessments of information worldwide about the risks of climate change, its potential consequences, and options for adaptation to and mitigation of consequences.

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Reference Location: 37.78 N, 120.00 W

Country: United States

Nearby Cities: Modesto, Merced, Turlock

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Figure 2: Ten-year moving average of temperatures in the San Joaquin Valley near Modesto, Merced, and Turlock shows temperature increases in recent years. Other areas in California’s San Joaquin Valley and Southern California show similar trends. From Berkeley Earth Surface Temperature.
California’s many unique microclimates allow farmers to grow a diversity of crops. The scientific consensus is that climate change will affect these microclimates, although there may be some regions that remain unaffected. Depending on the degree of change experienced in a region across several variables (e.g. temperature, rainfall, humidity, presence of plant and insect communities), there may be both negative and positive impacts to crop production. In some areas, certain crops will no longer be viable; simultaneously, there may be opportunities to grow these same crops (or new ones) in other regions of the state.
Several studies indicate that climate change will negatively impact many specialty crop yields and profits by the year 2050 and certainly by the year 2100 (Deschenes & Kolstad 2011; Medellín-Azuara et al. 2011; Lobell et al. 2006). For example, California has already observed a significant loss of winter chill hours, due to an increase in average winter temperatures (Baldocchi & Wong 2008). Winter chill hours are defined as the number of hours spent below 45° F, necessary for the flowers of fruits and nuts to bloom, and are required by certain crops to achieve high yields. Increased invasive pests, changes to plant and pest interactions, and increased plant and animal diseases in agriculture are some additional potential impacts from climate change.

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An Agricultural Vulnerability Index that takes into account climate change, crop vulnerability, land vulnerability such as urbanization and soil degradation, and socioeconomic pressures has been developed for California (Jackson et al. 2012). When climate vulnerability alone is considered, the majority of the Central Valley is “vulnerable,” coastal agricultural regions have “low” vulnerability, and the San Joaquin Valley and Southern California growing regions remain “moderately” vulnerable. But when climate change impacts are coupled with other vulnerability factors (such as soil degradation and urbanization), the regions where much of California’s agricultural production occurs, including the Central Valley and coastal growing regions, become the most vulnerable.
Growers in California are innovative leaders in agriculture. They continually develop their own adaptations to address inter-annual variability in weather as well as other changing environmental variables. Growers employ strategies such as diversifying their water portfolios, diversifying their crops, or diversifying revenue through agro-tourism or other opportunities in order to grow strong businesses. Thinking about climate change, however, requires thinking about these strategies on a generational timeframe and on a regional scale. According to a survey of about 160 growers in Yolo County, climate change was not listed as a high priority concern, although over 50% of the growers agreed “the global climate is changing” (Jackson et al. 2011). Although growers may not prioritize climate change as their primary concern, they have long been concerned about issues that are likely to be exacerbated by climate change such as unpredictable water supplies, the spread of invasive pests and plant and animal diseases and reduced availability of pollinators.
The severity of the impacts of climate change on food production will be variable and crop-specific. Growers should be made aware of adaptation measures available to them. Ensuring sustainable agricultural adaptation to climate change will require a concerted collaborative effort by growers, government agencies, and agricultural service organizations. The importance of this effort is highlighted in the California State Board of Food and Agriculture report, California Agricultural Vision: Strategies for Sustainability. Specifically, strategy nine is titled “Assure Agricultural Adaptation to Climate Change” and has the following objective – “Assure that all sectors of California agriculture can adapt to the most likely climate-related changes in seasonal weather, water supply, pests and diseases, and other factors affecting agricultural production” (California Department of Food and Agriculture 2012).
To identify specific strategies to assure agricultural adaptation to climate change, the California Department of Food and Agriculture (CDFA) convened the Climate Change Consortium workgroup in the fall of 2012 for two purposes:
1. To determine specific adaptation strategies that can be implemented now, and on-theground by specialty crop growers;
2. To provide direction and action measures to CDFA that can be initiated over the next several years, based on available resources, to help California agriculture adapt to climate change.
The Consortium includes representatives from several specialty crops commodity groups in California, growers from each of the top ten specialty crops in the state, scientists from the University of California and the California State University systems, University of California Extension Specialists, a member from the California Association Resource Conservation Districts, a member from the California Agricultural Commissioners and Sealers Association, and a certified crop/pest control advisor.

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Over the course of six months in 2012 and 2013, the Climate Change Consortium met four times to hear from leading scientific researchers in various fields of climate change at the interface of agriculture. The following chapters provide information presented and discussed at these meetings, and related recommendations for adaptation strategies. Understandably, a large number of adaptations highlight the need for further research. While the CDFA does not perform experimental research studies directly, the Department funds research activities and may submit proposals and refine request for proposals for research based on grower needs. The Department also provides growers with information on emerging research and research results. The development of strategic solutions with specific short- and long-term recommendations to address climate change impacts will help sustain California’s diverse specialty crop food production into the future.

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Chapter 2: Temperature

Introduction

This chapter covers temperature change impacts to California’s specialty crops, and proposed adaptation strategies to temperature change. This chapter addresses only direct temperature change impacts on California crops, such as warmer air temperatures. Changes in temperature can be linked to other climatic factors. For example, higher winter temperatures may result in reduced snowpack accumulation, which reduces irrigation supplies to agriculture; reduced water availability would therefore be an indirect temperature change impact.

Crops are sensitive to the magnitude

of change in temperature, extreme

Challenges:

temperatures (minimums and

maximums) and the timing of

• Increased average, minimum, and maximum

temperature changes (night vs. day,

temperatures in all seasons, and increased

spring vs. summer). The combination

temperature variability

of these factors constitutes

• More frequent and longer-lasting heat waves in

“temperature change.”

the summer

• Reduced number of winter chill hours and fog

Across the western U.S., average

• Uncertainty in temperature change projections

annual minimum and maximum

and forecasts

temperatures have increased since 1950; frost daysb have declined over

• High spatial variability of climate change and impacts of climate change

this same period (Bonfils et al. 2008).

Since 1920, California annual daytime

temperatures have increased 0.1° F per decade, and nighttime temperatures have increased 0.33 ° F per

decade (Moser et al. 2009). Statewide average temperatures increased approximately 1.7° F between

1895 and 2011. Warming has been greatest in the Sierra Nevada foothill and mountain region (Moser et

al. 2012). Data from weather stations located throughout the California Central Valley show increasingly warmer winters since the 1940s (Dettinger & Cayan 1995; Cordero et al. 2011). Over the entire 20th

century there has been a significant rate of warming for San Joaquin Valley minimum temperatures in all

seasons, with the greatest rate of warming in the summer and fall (Christy et al. 2006).

In general, warming is expected on an annual, seasonal, and even daily basis, with impacts differing by region. The significant, overall outcome of warming is the likely reduction in yield of some of California’s most valuable specialty crops, particularly perennial crops.

b Frost days are a count of days (within some defined period, such as a year) that have a daily average temperature below the freezing point.

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Climate ChangeCaliforniaFoodGrowersTemperatures