( CNN ) -- Because of the severe heat and drought in the Midwest , global food prices are going up . Why ? Because the U.S. is the leading producer and exporter of staple grains . We are for food production what Saudi Arabia is for oil production . Our crop shortages have ripple effects throughout the food system and disrupt the global markets , especially in the food-insecure nations . The U.S. has n't reached 2008 's level of high food prices yet because rice and wheat stocks are ample . These are the two most important food grains for human consumption worldwide . Corn and soybean levels are extremely tight , and their prices have skyrocketed since June . However , these two grains are mostly used as livestock feeds . Corn is also diverted to produce ethanol because of our government mandate . Opinion : Extreme heat and droughts -- a recipe for world food woes . Earlier this month , the United Nations urged the U.S. to ease its ethanol mandate . The origin of this policy goes back to 2005 when Congress set requirements of corn to be used for automotive fuel . In 2007 , the Energy Independence and Security Act greatly increased those requirements to improve air quality and become more energy secure . Behind the scenes , however , corn and other agricultural lobbyists were promoting the mandate to create a larger market for corn . Using current numbers , this year 's ethanol mandate would theoretically require 44 % of this year 's corn crop , a third of which is recycled back as distillers grains for livestock feed . We are being told by the ethanol producers , the corn growers and Secretary of Agriculture Tom Vilsack that eliminating the ethanol mandate would not significantly reduce global food costs . But how could that be when roughly 14 % of the world 's corn crop is being converted into ethanol in the U.S. ? In addition to corn being used for biofuel , taxpayer-subsidized biodiesel is using up more soybeans each year . While some say that attempting to change the ethanol mandate is politically impossible in an election year that depends so much on the Midwest swing states , there is a loud and growing chorus of voices that are calling for an urgent end to the mandate . Greg Page , CEO of Cargill , one of the world 's largest agricultural corporations , recently urged : `` We need to move to more market-driven biofuels policies , not inflexible mandates , subsidies and tariffs . '' Just as the USDA 's recent estimate of a corn yield at 123 bushels per acre is certain to be reduced further , its estimate of food costs rising only 3 % to 4 % next year is certain to be raised . The least politically palatable condition in any nation is high food prices . Expect beef , pork , chicken , turkey , eggs , fats and oils , cereals and dairy products to go up the most in the coming months . Americans have already reduced their meat consumption over the past few years partly because of higher prices . It is time for policymakers to admit they made a mistake in setting the corn ethanol mandate level too high in 2007 . This year , the mandate is 13.2 billion gallons of ethanol , which would require 4.7 billion bushels of corn . The mandate is set to top out in 2015 at 15 billion gallons . If politics dictates that we must have an ethanol mandate , then at the very least we should consider cutting the level by half , which could be done by using only 5 % ethanol , or E5 , in gasoline instead of E10 , which is a combination of 10 % ethanol and 90 % unleaded gasoline . The mandate should never be allowed to use more than 20 % of the annual U.S. corn crop . This amount would be enough to help stimulate corn demand for this overproduced commodity . As a bonus , more sustainable farming practices could return to the Midwest following this frenzy of growing corn on corn , fencerow to fencerow , to cash in on the high prices . What would make the most sense would be to scrap the national ethanol mandate altogether and let each state decide . Currently , ethanol use is not mandated in top corn producing states such as Iowa and Nebraska . These states choose to sell gasoline that does n't even contain ethanol . This would suggest that they would rather export the product than use it themselves . Since they tout their ethanol product so highly , and it is available to them locally , they should consider increasing their own use of the product . Meanwhile , consumers in low corn producing states such as Colorado and California are required to buy ethanol in every gallon of gasoline because ethanol use is mandated in those states . The argument for the ethanol mandate is being challenged because of today 's greater use of natural gas and the development of other fuel sources . It 's time for the mandate to reflect the realities of 2012 . It often takes a crisis to get government to take action and correct a policy that was wrong to begin with . This growing season , we have had extreme heat and drought in the most productive farming region in the world . Let 's use this unfortunate plight to get our ethanol policy right , before it causes food prices to go up more . The opinions expressed in this commentary are solely those of Kay McDonald .
Kay McDonald : Expect the price of meat , eggs and dairy products to go up . McDonald : America 's policy of diverting corn to ethanol production is causing high prices . She says if we must have an ethanol mandate , then we should cut the level by half . McDonald : Better still , scrap the national ethanol mandate and let each state decide .