Global Warming & CA’s Food Crisis ~ Adaptation Strategies for a Secure Future


In 1895 a Swedish scientist discovered the greenhouse effect. At the time, the concept of trapping gasses in the atmosphere (creating global warming) was thought to be an ideal development for preventing the next Ice Age. Today, this perspective is very different. What we now call climate change is having far reaching negative effects on the planet’s agricultural resources. Temperature affects crop yield, soil moisture, pest population and disease prevalence, all of which hinder agricultural production.

In May, the Giannini Foundation hosted a one-day conference in Sacramento called “Climate Change: Challenges to California’s Agriculture and Natural Resources.” I attended the conference and spent the day surrounded by scientists, policy makers, and educators, learning about the implications that climate change will have on California food production.

GianninilogoOne of the most important panels from the day was driven by the pressing question: Will adaptation mitigate the impacts of climate change? Moderated by Aaron Smith, a professor at UC Davis, the panel consisted of:

Climate change is a very real issue for California farmers, and each year increasing temperatures, desertification and water scarcity are dramatically affecting food production. So, we ask ourselves: what does it mean that some of the most fertile soil in the U.S. is becoming a desert? Can we adapt in time to save the future of agriculture in California?

Climate change and adaptation strategies

Climatologists predict that the current drought in California will likely be over by the end of 2015 due to the 78% probability of an El Niño next winter. However, the duration and intensity of the drought we are experiencing is becoming a common effect of climate change around the globe. History has shown that California typically experiences a drought about once a decade for a two to three-year stretch.

It’s now projected, however, that California’s droughts will happen with more frequency and last longer than they have in the past. These increasingly severe droughts are projected to reduce the net usable water supply in the state by up to 30% in the next 70 years, having a profound impact on our ability to grow food.

There are two important changes the panel recommended in order to mitigate the effects of these prolonged droughts. The first is to change the types of food we grow, and the second is to better manage our water resources.

Changing what we grow and how we grow it

fruit369x261sThe majority of crops grown in California don’t like hot temperatures. When exposed to prolonged hot days, crop development is sped up and moisture is lost within the plant, resulting in lower yields. Hot days also increase soil temperature, which dries out the soil and roots, and induces water stress, thus lowering productivity. We need to anticipate the rising temperatures and adapt by adjusting what we grow and how we grow it.

What about perennial versus annual crops? Many permaculturalists advocate for perennial crops for their extensive root systems that can reach deep water sources during drought which annuals cannot. Currently, a large percentage of California farmers grow perennial crops, such as apples, grapes and almonds.

Despite this trend, the conference panel advocated for annual crops to allow farmers the flexibility to adapt to volatile climate changes. They noted the challenges in becoming invested in growing a single perennial crop for many years at a time, not allowing changes to crop plans when the weather demands it.

Annual crops, on the other hand, allow for greater crop diversity and allow the farmer more opportunity to adapt with the season. Although annual crops are a potential way to mitigate climate change, specialists at the conference did note that more research is needed to better understand how warmer temperatures affect individual crops.

Better water management strategies

There are two competing demands for water in California: urban and agricultural.

It’s projected that, for the next 50 years, urban demand for water will grow at a rate of about 0.5% per year. This is much lower than it has been in the past (5-10% per year growth rates) due to the rising cost of water and successful conservation efforts, such as rainwater capture and desalinization in coastal regions. In Southern California, there have also been successful campaigns to lower individual water use by taxing heavy users. Still, the demand still far exceeds our conservation rates, so more work is needed.

Meanwhile, agricultural demands for water have actually remained much more constant, showing little growth in overall water consumption over the years.  But, as the reliance on perennial crops increases throughout the state, even if water use remains steady, we will need to consider more carefully the types and varieties of crops to produce as we may need more water to produce the same yields.


It’s no question that agriculture also needs to dramatically reduce its water use – and fast. But what does this mean?

Maybe it’s allowing some land to go fallow, planting native grasses or using heat tolerant annual crops that require less water. It could mean rotating crops more frequently to reduce weeds and cover cropping for soil moisture and nutrient retention. California is in an interesting situation where water is scarce but land is plentiful: we will have more land than water to irrigate it.

Protecting our groundwater

Groundwater has been our backup when surface water is depleted during droughts, and currently groundwater levels are at all time lows. Thus, we need to implement large and immediate cutbacks in overall usage. The most efficient groundwater regulations have worked by charging people to replace the cost of what they have over-pumped.

Ultimately, more research is needed to understand how our environment is going to change as the climate does. We can start implementing these changes now and, with more information, we can continue to adjust our water consumption and adapt our growing methods to supply food for California and beyond.  In addition to water conservation, by moving the bulk of California crops from perennial to annual, we can more quickly adjust to dry seasons. Of course, this presents its own list challenges.

Overall, planning for the future, conserving our water, and funding more research will allow us to better handle climate change head on. Hopefully, we continue to make this a priority and better plan for the future, now.

For more information on the Climate Conference, visit the Giannini Foundation.

For other practical water-related resources, including reports on drought and climate change trends, see our Water & Irrigation Toolkit.  

If you happened to miss them, check out our recent blog series on water and drought management:

If you have questions, words of wisdom or other great tips for the many farmers dealing with agriculture and climate change, visit FarmsReach Conversations and post a question or comment!

If you have other great climate change resources to shareget in touch.  We’d love to hear from you!

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