USDA: Warming Will Devastate Agriculture

February 7, 2013

Phil Robertson is a senior crop and soils researcher at Michigan State University, and a contributing author of the forthcoming US Global Change Research Program report on climate change. I interviewed Dr. Robertson in early July, 2012,  as the drought was deepening, and the realization was setting in that we were in a historically intense dry period.

I clipped the middle part where we discussed drought events that were current at that moment – what’s most interesting is his generic assessment of the science on “co2 fertilization” and what deniers like to call the “greening of planet earth”.

I should see Phil again next week at a Town Hall meeting in Ann Arbor, which will go over some of the key findings of the newest iteration of the Global Change Research report.

One of the most absurd of Climate denial myths, and therefore one of the most cherished – is that “CO2 is good for plants” – therefore, global warming will benefit agriculture. The logic is, apparently, that Co2 is an inconsequential trace atmospheric gas that has no effect,… and is critical to all life on the planet.

To follow up on this, you could, of course, poll midwest farmers to find out how all that co2 has been helping with crops during this ongoing drought, do a quick review of grain price trends..


Or, you could, as the USDA has, review 1400 technical publications on the topic.

Farm Futures:

…the agricultural report indicates increases in atmospheric carbon dioxide, rising temperatures, and altered precipitation patterns will affect agricultural productivity. USDA says the changing climate will exacerbate the stresses already occurring from weeds, insects, and disease.

Additionally, increases in the incidence of extreme weather events will have an increasing influence on agricultural productivity. Over the next 25 years, the effects of climate change on agricultural production and economic outcomes for both producers and consumers in the United States are expected to be mixed, depending on regional conditions.

Beyond 2050, changes are expected to include shifts in crop production areas, increases in pest control expenses, and greater disease prevalence. Although some regions will be affected more than others, these disturbances are likely to change the structure and function of ecosystems across millions of acres over a short period of time.

A special report on forestry notes how forests will be affected – anticipated changes include increased tree mortality, changes in species assemblages, and reduced water quality.

USA Today:

WASHINGTON — Climate change could have a drastic and harmful effect on U.S. agriculture, forcing farmers and ranchers to alter where they grow crops and costing them millions of dollars in additional costs to tackle weeds, pests and diseases that threaten their operations, a sweeping government report said Tuesday.

An analysis released by the Agriculture Department said that although U.S. crops and livestock have been able to adapt to changes in their surroundings for close to 150 years, the accelerating pace and intensity of global warming during the next few decades may soon be too much for the once-resilient sector to overcome.

“We’re going to end up in a situation where we have a multitude of things happening that are going to negatively impact crop production,” said Jerry Hatfield, a laboratory director and plant physiologist with USDA’s Agricultural Research Service and lead author of the study. “In fact, we saw this in 2012 with the drought.”

By the middle of the century and beyond, adaptation becomes more difficult and costly as plants and animals that have adapted to warming climate conditions will have to do so even more — making the productivity of crops and livestock increasingly more unpredictable. Temperature increases and more extreme swings in precipitation could lead to a drop in yield for major U.S. crops and reduce the profitability of many agriculture operations. The reason is that higher temperatures cause crops to mature more quickly, reducing the growing season and yields as a result. Faster growth could reduce grain, forage, fiber and fruit production if the plants can’t get the proper level of nutrients or water.

Among the biggest threat to crops from rising temperatures and accelerated levels of carbon dioxide is an increase in the cost for the agricultural industry to control weeds, a challenge that tops more than $11 billion annually, according to the study. Warmer weather provides an ideal atmosphere for weeds to thrive, but at the same time, it can stunt the growth of traditional plants like grain and soybeans.

The USDA review said climate change will affect livestock by throwing off an animal’s optimal core body temperature, which could hurt productivity and limit the production of meat, milk or eggs. A warmer and more humid weather pattern is likely to increase the prevalence of insect and diseases, further diminishing an animal’s health and output.

The 146-page report, written by a team of 56 authors from the federal government, universities, the private sector and other groups, stopped short of providing answers on how to stop or curtail global warming. The analysis was done by reviewing more than 1,400 publications that looked at the effect of climate change on U.S. agriculture.

US Global Change Research Program – draft report for 2013 – Chapter 18, “The Midwest” – Key messages:

1. In the next few decades, longer growing seasons and rising carbon dioxide levels will increase yields of some crops, though those benefits will be increasingly offset by the occurrence of extreme events such as heat waves, droughts, and floods. In the long term, combined stresses associated with climate change are expected to decrease agricultural productivity, especially without significant advances in genetic and agronomic technology.

Below, the “CO2 is Plant Food” Crock:


9 Responses to “USDA: Warming Will Devastate Agriculture”

  1. “Although some regions will be affected more than others, these disturbances are likely to change the structure and function of ecosystems across millions of acres over a SHORT period of time.”

    ( Climate extremes initiate ecosystem-regulating functions while maintaining productivity, Jentsch (2011):

    “Surprisingly, in the face of severe drought, above- and below-ground primary production of plants REMAINED STABLE ACROSS ALL YEARS of the drought manipulation.”

    ( ”The ecological role of climate extremes: current understanding and future prospects.”, Smith (2011): “Synthesis. The papers in this Special Feature suggest that although the occurrence of ECEs may be common in palaeo-ecological and observational studies, studies in which climate extremes have been experimentally imposed OFTEN DO NOT RESULT IN ECOLOGICAL RESPONSES OUTSIDE THE BOUNDS OF NORMAL VARIABILITY OF A SYSTEM.”
    “There is medium confidence that some regions of the world have experienced more intense and longer droughts, in particular in southern Europe and West Africa, but in some regions droughts have become less frequent, less intense, or shorter, for example, in central North America and northwestern Australia.”

    ( Nielsen-Gammon: “… global warming on Texas had a net beneficial effect in the 20th century …”

    I read the report. Deficiencies in the references that I was already noticed …

    The general conclusion about agriculture: the proposed future effects of rising temperatures on agriculture are at least one order of magnitude smaller than changes observed since about 18?? as a result of better technology and up to two orders of magnitude smaller than those that can be achieved by the effective further development of the technology (ia Budyko). These improvements reflect a remarkable improvement in society’s adaptive capacity, likely due to greater wealth and better technology, indicating that humanity is coping better with extreme weather events than we thought.

    • ontspan Says:

      Regarding the first link regarding the response of grass to drought I notice that you ‘forget’ the following very significant quote:
      “Remarkably, despite stability in biomass production, drought decreased leaf protein content and the leaf nitrogen isotope signature and increased C:N ratio and carbohydrate content in leaves, thus decreasing feed value of plant tissue.”

      Regarding the last link, the full quote gives a different message then the above post seems to present:
      “If a stable climate is desirable, which seems to be the prevailing consensus, global warming on Texas had a net beneficial effect in the 20th century, by counteracting cooling from other mechanisms. However, none of the viable cooling mechanisms are sustainable, so warmer temperatures in Texas are extremely likely in the future, and based on temperatures in the first eleven years of the 21st century, those days are already here.”

      Quotemining to prove a point is typical contrarian behavior.

  2. Prof. Strephen Long form Uni of Illinois has a similar take, but also mentions the importance ofchanges to Ozone levels.

  3. […] Phil Robertson is a senior crop and soils researcher at Michigan State University, and a contributing author of the forthcoming US Global Change Research Program report on climate change. I intervi…  […]

  4. […] This comes from a post by Peter Sinclair: USDA: Warming Will Devastate Agriculture. […]

  5. […] 2013/02/07: PSinclair: USDA: Warming Will Devastate Agriculture […]

  6. […] 2013/02/07: PSinclair: USDA: Warming Will Devastate Agriculture […]

  7. daveburton Says:

    Hansen says fossil fuel use is greening the Earth, not only through CO2 fertilization, but also through NOx emissions & consequent nitrogen deposition; see also the discussion here.

  8. Lake Rose Says:

    This is so interesting blog. You are best listing knowledge provide at this site. I am very excited read this nice article.

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