Research About Climate Change

Climate Change and the Impact on Agriculture

According to the California Department of Food and Agriculture, California is the United States’ sole exporter of many agricultural commodities, supplying 99 percent or more of the following: almonds, artichokes, dates, dried plums, figs, garlic, kiwifruit, olives and olive oil, pistachios, raisins, table grapes, and walnuts. Being the United States’ largest supplier of many agricultural commodities, California has a large role in the nation’s food supply, as well as a larger impact on the nation’s economy. Despite this, the recent problems arising from climate change have been causing turmoil all over California and has been negatively affecting the agricultural side of the sunshine state.

Many factors contribute to the overwhelming problem that has come to be climate change. When most people hear climate change, they think of the increasing temperature of the Earth due to carbon emissions. Carbon emissions, while a large problem itself, is not the only cause of climate change. Other causes of climate change include: the acidification of the oceans of the earth, deforestation of forests, and many more events. According to NASA, “climate change is a long-term change in the average weather patterns that have come to define Earth’s local, regional and global climates”. This broad definition can mean many different things which can be described as causing climate change. However, there are a few important factors of climate change that have a large and substantial impact on California agriculture and livestock.

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A main result of the carbon emissions that have been released into the atmosphere has been the increase of temperature all over the globe. This is mainly due to greenhouse gases, which are defined as “gases that trap heat in the atmosphere of the earth” (EPA).Figure 1 shows the increase of temperature over the past few decades in California history due mostly to the effects of greenhouse gasses. This increase in temperature has caused many local crops to grow in non-ideal temperatures, resulting in a decrease in total yields for agricultural farms. Not only has crop production been affected, according to a group of UC researchers on climate change, but also “frequent heat waves in the state impact health, economic, ecological, and social parameters, resulting in heat-related deaths and illnesses, decreased agricultural production, increased water use and thus irrigation requirements, and greater electricity demands” (Pathak).

This increase in temperature globally has caused problems all over the globe, with California being no exception. An analysis by the UC research team also found that “the last three wet seasons (October 2011–March 2014) represent the driest 30-month period since records began in 1895” (Pathak). This has resulted in some of the driest years in California history due to a steady decrease in rainfall. Not only is the yearly precipitation affected by the change in temperature but the snowfall that occurs across Northern California and the Sierra Nevada mountains has decreased as well. This snowfall accounts for 80% of the state’s precipitation per year (Pathak). Much of the snow is important for being used to fill up surface

 

Figure 1: Change in CA Daily Maximum Temperature from 1961-beyond. Prediction by Pathak, et al.

reservoirs and supply many parts of California with a steady water supply. However, with higher temperatures, this snow melts earlier than expected, which usually causes mass flooding of the surrounding areas before the water can be stored. Higher temperatures also cause less snow to fall, and in the coming decades, California could lose as much as 65% of snowfall with no change to global warming (Pathak). This trend can be seen in Figure 2, displayed below, which predicts the change in snowfall due to change in temperature.

Figure 2: Historical and projected snowpack for the Sierra Nevada. Pathak, et al.

Much of this water is necessary for irrigation of California agriculture due to the arid climate present in much of California. A collaboration between UC Berkeley and UC San Diego researchers found that “the decrease in water availability when it is needed most, during the growing season, will increase the demand for irrigation, putting more pressure on river and groundwater systems” (Shlenker 22).These groundwater and river systems will already have a

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decrease in water due to the decrease in precipitation, causing an even greater strain on the water supply of California.

This strain will not only be felt on the agricultural level but also on the consumer level with the inevitable increase of prices in agriculture and even livestock products due to the decreased supply. This change has been of particular interest to a panel of researchers who were interested in predicted these economic changes to agriculture in the coming years. These researchers created a computer model, called the Statewide Agricultural Production Model (SWAP), to simulate the effects of climate change on the economics of agricultural in agriculturally rich areas in California. With this model, the researchers concluded that major decreases in agricultural product are inevitable without a solution. These predictions, based off potential scenarios in 2050, conclude that many crops will see very massive decreases in the land.

Figure 3: Predicted percent change of land where agricultural products are grown in California. Howitt and Lund.

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The panel concluded that “Sacramento, San Joaquin, and Southern California regions show irrigated pasture acreage reduced by over 90%. Field crops and grains show significant acreage decreases as well, with grain production dropping out of the Sacramento Valley entirely” (Howitt and Lund). This is in part because of lower yields of crops, as well as the inevitable switch by most farmers to more drought-resistant crops. Since overall crop production will fall or at least outsourced to other geographical locations outside of California, most prices for crops will increase moderately in the United States, if not globally as well. This would be due to the decrease in crop yields offset by the large demand of many agricultural products, like citrus. This increase in price will be felt on the consumer and producer level, with both sides feeling the increasing cost of buying or producing these commodities, according to the model. In fact, many citizens of California have already felt the effects of the decrease in availability of water. According to Circle of Blue, a news agency specifically dedicated to water-related issues, Los Angeles has seen water rates increase by 71 percent over the past 10 years (Bland). This trend can be seen in Figure 4, which shows that most families in Los Angeles have seen high increases in their water rates in the past decade.

Figure 4: Average monthly cost of water in Los Angeles 2010-2018. Walton, Brett, LaFond.

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Figure 5: Change in crop production and revenue. Howitt and Lund

With the problems that can arise from climate change being massive, why has climate change not been dealt with or at least discussed in the past? The answer is complicated. Despite the high amount of academic research and governments of many nations declaring climate change a global emergency, there are some skeptics who believe that climate change is not a danger, but rather a natural change for the planet. These skeptics are also present in the debate of how climate change affects California agriculture. UC Davis professors Warren Johnston and Alex McCalla are researchers who, through predictions and reasoning of their own, have stated that “so far, it [California] has always emerged from each crisis by rapidly adjusting and changing. California agriculture is very different than it was a decade ago, 50 years ago.” They go on to say that “California agriculture in 2020 or 2050 will be very different than it is now, but it will still maintain its vitality, through experiencing, as is its fate, chronic and sometimes powerful adjustment pressure. Those forecasting its demise simply do not understand its natural and human assets nor do they acknowledge the dynamic resilience of California agriculture.” While California is in fact adapting to the changes caused by climate change through implementation of drought resistant crops and innovative ideas such as high-fertility soil (Sommer), climate change is not a temporary issue. Agricultural land cannot be easily or quickly moved, as much of the land used for growing crops must first be turned into fertile ground through years of work. Not to mention the cost of moving millions of crops to a completely different area and the effect it will take on the land will be massive to both the economy and the ecosystem.

According to NASA, most of the prediction models showing dangerous increases in temperature of the earth made during the past 50 years have been accurate (models like Figure 6, for example), and no evidence has been found that these climate models were overestimated or underestimated the warming over the period of the projections (Buis). If left ignored, climate

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change will snowball into a problem that humanity will not be able to deal with. If left unchecked in the coming years, climate change will render parts of the earth uninhabitable and much of the land infertile. California has already started to feel the consequences of climate change with increase in prices of agricultural crops and fresh water for irrigation or consumption. This will occur due to the decrease in total crop yield and freshwater availability. While these consequences are minor for the time being, major repercussions will occur if nothing is changed. At that point, California agriculture will become the least of our problems.

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Figure 6: Model for temperature increase that was used in 2004 to predict climate change. Buis.

Work Cited

Bland, Alastair. “Californians Are Struggling to Pay for Rising Water Rates.” Water, News Deeply, 27 Feb. 2018, www.newsdeeply.com/water/articles/2018/02/27/californians-are-struggling-to-pay-for- rising-water-rates.

Buis, Allen. “Study Confirms Climate Models Are Getting Future Warming Projections Right – Climate Change: Vital Signs of the Planet.” NASA, NASA, 9 Jan. 2020, climate.nasa.gov/news/2943/study- confirms-climate-models-are-getting-future-warming-projections-right/.

CDFA. California Agricultural Statistics Review 2015-2016. www.cdfa.ca.gov/statistics/PDFs/2016Report.pdf.

Hayhoe, Katharine, et al. “Emissions Pathways, Climate Change, and Impacts on California.” PNAS, National Academy of Sciences, 24 Aug. 2004, www.pnas.org/content/101/34/12422.

Johnston, Warren. California Agriculture in the 21st Century. Giannini Foundation of Agricultural Economics.

Medellin-Azuara, Josue, et al. Economic Impacts of Climate-Related Changes to California … 24 Nov. 2011, www.researchgate.net/publication/227583832_Economic_Impacts_of_Climate- Related_Changes_to_California_Agriculture.

“Overview of Greenhouse Gases.” EPA, Environmental Protection Agency, 11 Apr. 2019, www.epa.gov/ghgemissions/overview-greenhouse-gases.

“Overview: Weather, Global Warming and Climate Change.” NASA, NASA, 28 Aug. 2019, climate.nasa.gov/resources/global-warming-vs-climate-change/.

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Pathak, et al. “Climate Change Trends and Impacts on California Agriculture: A Detailed Review.” MDPI, Multidisciplinary Digital Publishing Institute, 26 Feb. 2018, www.mdpi.com/2073-4395/8/3/25.

R., Howitt, and Lund J. R. “Economic Impacts of Climate-Related Changes to California Agriculture.” Economic Impacts of Climate-Related Changes to California Agriculture | Center for Watershed Sciences, 2012, watershed.ucdavis.edu/library/economic-impacts-climate-related- changes-california-agriculture.

Schlenker, Wolfram, et al. Water Availability, Degree Days, and the Potential Impact of Climate Change on Irrigated Agriculture in California. Apr. 2005, are.berkeley.edu/~fisher007/ClimateChange.pdf.

Sommer, Lauren. “California’s Latest Weapon Against Climate Change Is Low-Tech Farm Soil.” NPR, NPR, 2 May 2019, www.npr.org/2019/05/02/718736830/californias-latest-weapon-against-climate- change-is-low-tech-farm-soil.

Walton, Brett, and Kaye LaFond. “Water Pricing.” Circle of Blue, Brett Walton Https://Www.circleofblue.org/Wp-Content/Uploads/2018/06/Circle-of-Blue-Water-Speaks- 600×139.Png, 25 Nov. 2019, www.circleofblue.org/waterpricing/.