July 20, 2011


USDA uncertain of near-term climate effects on crop yields



The USDA is finding it almost impossible to estimate the effects of climate on food production for the near future, but forecasts climate issues affecting world food production by 2050.


"They are very elaborate models," said USDA's chief economist Joseph Glauber, referring to climate-crop forecasting in an interview on Tuesday (Jul 19) on the sidelines of a farm lending conference at the Kansas City Federal Reserve.


"Take into account all the fundamentals on crops and yields. You also have to build in all this climate variability and predictions about climate variability. The range of potential outcomes is pretty large," Glauber said.


"We just don't consider that in our 10-year baseline. We assume some trend growth; we really don't even look at variability. That's probably proper for a 10-year forecast horizon."


Glauber cited studies by the Intergovernmental Panel on Climate Change (IPCC) and the UN's Food and Agriculture Organization (FAO) as important models to build upon.


"Climate doesn't make a difference much over 10 years. There is a lot more variability now relative to say 10, 15 years ago. But the real changes we are talking about here start manifesting themselves over 30, 40, 50 years," Glauber said.


"World food needs will increase by 70% by 2050. By 2050, you can have climate issues," he added.


"The important thing in looking at these longer run forecasts is things like water availability. These are big stressors when you talk about food production needing to increase by 70%."


The USDA's crop reports, such as the monthly World Agricultural Supply and Demand Estimates (WASDE) and its 10-year baseline crop outlooks, are key benchmarks for the world food and farming industries, given the vast domestic and world data gathering the agency employs.


"To take our crop forecasting models -- they are what they are -- and try to marry in a lot of climate stuff, it's pretty cumbersome," Glauber said.


"With climate comes looking at land use -- forest versus pasture versus cropland," Glauber said. "We are just beginning to see some of the modeling on that."


David Fischhoff, vice president of technology strategy at seed producer Monsanto, told the conference on Tuesday (Jul 18) that climate change effects are already at work in many areas of the world, hurting yields in some areas while helping others.


"There may be near-term benefits from global warming in some regions of the world, for example the northern hemisphere," Fischhoff said. "At the same time, the long-term trends indicate we will see more extreme weather patterns, more extreme droughts in parts of the world that are already dry including the southwestern US."


"Although we can't make precise predictions on global weather patterns with any great degree of confidence today, the trends are pretty clear," he said.


Fischhoff said Monsanto, a biotechnology pioneer, will be enhancing herbicide and insect tolerance crop technology and also moving more into yield and stress traits, including single genes that he said might be able to boost yields in corn and soybeans by 5%.


Up until the mid 2020s bigger yields will come from breeding and agronomic practices, he said. "In the later part of the next decade to the mid 2020s and beyond expect the greater contribution to that yield to come from new biotechnology traits."

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