in the early 21st century, it became more difficult to raise almonds in a sustainable manner. The issue is complex because of the high amount of water needed to produce almonds: a single almond requires roughly of water to grow properly. Regulations related to water supplies are changing so some growers have destroyed their current almond orchards to replace with either younger trees or a different crop such as pistachio that needs less water. Sustainability strategies implemented by the Almond Board of California and almond farmers include: tree and soil health, and other farming practices minimizing dust production during the harvest bee health irrigation guidelines for farmers food safety use of waste biomass as coproducts with a goal to achieve zero waste use of solar energy during processing job development support of scientific research to investigate potential health benefits of consuming almonds international education about sustainability practices Production In 2020, world production of almonds was 4.1 million tonnes, led by the United States providing 57% of the world total (table). Other leading producers were Spain, Australia, and Iran. United States In the United States, production is concentrated in California where and six different almond varieties were under cultivation in 2017, with a yield of of shelled almonds. California production is marked by a period of intense pollination during late winter by rented commercial bees transported by truck across the U.S. to almond groves, requiring more than half of the total U.S. commercial honeybee population. The value of total U.S. exports of shelled almonds in 2016 was $3.2 billion. All commercially grown almonds sold as food in the U.S. are sweet cultivars. The U.S. Food and Drug Administration reported in 2010 that some fractions of imported sweet almonds were contaminated with bitter almonds, which contain cyanide. Spain Spain has diverse commercial cultivars of almonds grown in Catalonia, Valencia, Murcia, Andalusia, and Aragón regions, and the Balearic Islands. Production in 2016 declined 2% nationally compared to 2015 production data. The 'Marcona' almond cultivar is recognizably different from other almonds and is marketed by name. The kernel is short, round, relatively sweet, and delicate in texture. Its origin is unknown and has been grown in Spain for a long time; the tree is very productive, and the shell of the nut is very hard. Australia Australia is the largest almond production region in the Southern Hemisphere. Most of the almond orchards are located