The carbon footprint of embedded water in Califtornia’s agricultural products has not been thoroughly studied before. However, related topics have been on the table to solve the sustainable development problems. This research tries to find out the energy consumption of the water embedded in the exported agricultural products from Califtornia. It also aims to figure out the nation scale distribution of the carbon footprint that was studied in this research. The results show that the water footprint of the agricultural products is around 22.3 Gm3 and the total carbon footprint is 8.9 million metric tons of CO2. The top three regions that have the highest water and carbon footprint are European Union 27, China, and Japan. We studied the carbon footprint by researching the water footprint of all the agricultural products. Based on the energy usage per unit water sources published by the Califtornia Energy Commission and the global average water footprint of agricultural products from previous work , we calculated the carbon-equivalent of the agricultural products’ carbon footprint. And based on the result that the carbon footprint of the embedded water of agricultural products is only 2% of the total carbon budget with the water footprint contributes to 25% of the total, we believe that Califtornia has performed well in managing the energy in agriculture-water area, but it still has improvement space in the management of the water resource.The carbon footprint is defined as a measurement of the total amount of carbon dioxide emission that is directly and indirectly caused by an activity or is accumulated over the liftetime of a product. Due to its impact on the environmental issues such as global warming, the carbon footprint is the hot topic in the field of environmental science. Virtual water trade refers to the hidden flow of water if food or other agricultural products are traded from one place to another. At the same time, square black flower bucket wholesale virtual water is related to the carbon footprint directly and indirectly.
Some studies have focused on the virtual water trade aiming to conserve water in the production of crops by increasing product export to areas with less water needs . In this effort, the research on virtual water of agricultural products has the potential to reduce economic costs, where water withdrawals may have greater impacts on water-lacking regions than on water-abundant regions. However, few studies have analyzed the internal virtual water flow dynamics of the U.S. on a state or regional scale. And fewer have focused on the associated carbon footprint on a state or regional scale in the U.S. In this study, we calculated the carbon footprint of the exporting agricultural products of Califtornia to their destinations by firstly exploring the products’ water footprint. Previous virtual water quantification studies have identified the U.S. as the leading global virtual water exporter . Thus we hypothesize that Califtornia is the largest virtual water exporting state in the country. Accordingly we also hypothesize that Califtornia is releasing a great amount of carbon dioxide related to the embedded water of agricultural products. And in this research, we focus on the carbon footprint associated with energy cost by the embedded water in agricultural products exported from Califtornia to other regions of the world.Nowadays, carbon emission is a worldwide topic that hinders the development in many various sectors of human lifte. Every year, the United Nations would regulate the carbon budget for most of the countries. How to use the carbon budget efficiently is a mandatory issue to be managed. At the same time, water resources shortage is becoming an urgent problem all over the world, as energy deficiency is an equally critical problem. Califtornia is facing an unprecedented water crisis in history where water treatment is the largest energy use of the state taking up approximately 19 percent of the total annual electricity consumption . It will cost significant financial investment to keep the water supplies sufficient for next several decades. New regulations and court decisions have resulted in the reduction of water delivery from the Sacramento-San Joaquin Delta .
In some areas of the state, the quantity of underground water and surface water supplies is experiencing rapid decrease . The production of water for agriculture requires an enormous amount of energy. The energy water relationship is particularly inseparable in the Southwestern arid and semi-arid regions of the United States, where significant amounts of energy are used to import water. Califtornia is exceptionally vulnerable because its water sector is the largest energy user in the state, estimated to account for 19 percent of the total electricity consumed annually . Another fact is that the annual water used in growing agricultural products in Califtornia is much greater than the total amount used by the other fields such as commercial and industrial applications . Less known is the amount of water embedded or embodied in agricultural products that are exported to other states and countries. For some certain kinds of agricultural products, Califtornia is dominating the supply of the whole U.S. market, such as almond, grape, strawberry, processed tomato, and lemon .Table 5 shows that the exports of agricultural products have been increasing from 2010-2012. Almond as the most exported agricultural product had a growth of 19%. Almond, walnut, wine, and dairy products are the top four in terms of quantity of export agricultural products. All products summed up increased expert by agricultural products 8%. Agricultural product exports provided Califtornia with economic benefits. However, considerable amount of water was consumed during the process of irrigation.As shown in Figure 4 the trend of agricultural product exports from U.S. has been rapidly growing since year 2000. As one of the largest agriculture state of the U.S., Califtornia is facing an increasingly serious water and energy crisis. Califtornia exports agricultural products to more than 156 countries and agricultural export earnings totaled $16.87 billion in 2011 . A growing population is worsening the effects of multi-year droughts in many regions, threatening Califtornia’s already stressed and fragile water systems. The world population would reach 9.6 billion in 2050 . And the Califtornia population will across 50 million at 2050 , which accounts for a 32.4% increase from now. Therefore the food industry is expected to face the problem of food shortage, and one of the underlying causes of food shortage is the limited irrigation water resource. Furthermore, water supply including transportation, treatment, and dispensing is energy-intensive.
Carbon footprint associated with such energy cost is also expected to be tremendous, thus alarming from an environmental perspective. The total CO2 emission from United States in 2012 is around 1.4 billion tons of carbon . And the carbon budget for Califtornia is presently dominated by 115 MMTCE per year in fossil fuel emissions of CO2 to meet energy and transportation requirement. Recently, it is worth noticing that state legislation requires Califtornia to reduce GHG emissions to 1990 levels by 2020 and by another 80% below the 1990 levels by 2050. But its growing population and the demand for all forms of energy will make meeting these targets a major challenge.Based on the data of agricultural product export distribution in different destinations and the total water footprint/carbon footprint of each agricultural product, the weighted water footprint for all the exported agricultural products could be computed. The associated carbon footprint from water treatment could be estimated consecutively. Furthermore, the carbon footprint of the agricultural product export to one country is simply the summation of that of each agricultural product. Especially, in an industrial beef production system, it takes on average three years before the animal is slaughThered to produce about 200 kg of boneless beef. The animal consumes nearly 1,300 kg of grains , 7,200 kg of rough ages , 24 cubic meters of water for drinking and 7 cubic meters of water for servicing. This means that to produce one kilogram of boneless beef, we use about 6.5 kg of grain, 36 kg of rough ages, and 155 liters of water . Producing the volume of feed requires about 15,300 liters of water on average. The water footprint of 1 kg of beef thus adds up to 15,500 liters of water.There are several aspects that could have changed the results of this research. Income from agriculture is 50% of Califtornia’s GDP and is twice the amount of income from other industrial sectors. Being water arguably the most critical factor in agriculture, water stress is prevalent in Califtornia. In fact, plastic square flower bucket water footprint in agricultural product exports was 25 Gm3 water in 2011. Califtornia has been suffering from the droughts in recent years as shown in Figure 5. As the climate continues to warm and soil moisture deficits accumulate beyond historical levels, relevant studies suggest that sustaining water supplies in parts of the Califtornia will be a challenge . Import tax is directly proportional to the total price of import products, which in author’s view is biased. Products with low price/value yet high water footprint, such as beef and oranges, give the customer countries advantages over the others. With water being increasingly valuable, adjustments on import tax is needed for water resource management. The water footprint of Califtornia agricultural products estimated in the current study should be further compared to the water footprint of the U.S.. In the study of Mekonen , the total water footprint of agricultural production of USA is 800 Gm3 /yr, much bigger compared to the 25 Gm3 . However, this study focuses on not only the total quantity, but also the water footprint flow by looking at the commerce flow of each product. The import of water footprint of Califtornia should also be researched to provide an accurate understanding of the relationship between economics and environment. Furthermore, study can be expanded to the other state to comprehensively examine the virtual water flow within the entire nation.
Given that the water supply distribution in the States is vastly varied, the evaluation on water footprint flows can serve as a reference for decision making in commerce and economic management. Methodologies and results in this study can serve as preliminary results for further applications. Carbon footprint as the other objects of this study is equally important as water footprint. In a similar way, CO2 emission is becoming an increasingly impactful metric in many sectors of economy, and will be certainly put on the table during decision-making. Water supply in Califtornia is uniquely costly in terms of energy, standing at 19% of the total energy use of which 40% is used in agriculture . Therefore, the energy used in agriculture is 7.6% of the total energy consumption of Califtornia. The precipitation situation of Califtornia fluctuates from year to year, especially from 2011 to 2014, as shown in Figure 5. The Califtornia has been suffering from the worst drought in 50 years. In a drought year, instream water would be largely reduced, which means waster use in agriculture will have to rely more on other energy-intensive water supplies. Consequently, the carbon footprint for agriculture water use will be exacerbated. With year 2011 being a recent peak for precipitation, the results from this study on carbon footprint in agriculture exports, in a sense underestimated the water deficiency and energy consumption. The total carbon footprint calculated by this study for the agricultural products exported is around 9 million metric tons CO2, which is 2.2% of the carbon budget for Califtornia . The difference between the two numbers 2.2% and 7.6%, in the author’s view, is due to primarily the fact that export is only one of the end use for agricultural products. Secondly, the use of global average value for each product’s water footprint likely overlooks some of the features of regional products. In addition, inefficiency in agriculture water use for each type of product is open to exploration. From the CEC report of 2007 , the largest contribution to carbon footprint is from energy for electrical power generation and the fuel for transportation. The results of this study show that water footprint of agricultural product exports is 25% of the total, while the carbon footprint is 2.2% of the carbon budget. Therefore at the current stage, water consumption seems to be a more critical issue than CO2 emission. Nonetheless, what we considered in this research is the carbon footprint from the embedded water, but there are still many water-irrelevant activities that contribute to the total carbon footprint, such as the transportation energy and human labor carbon footprint. Hence, the carbon footprint from the entire process of agricultural production would be higher than that resulting from this research. Another fact is that if more reclaimed water was used in agriculture, lower carbon footprint would be achieved.