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Monday, April 7, 2014

Climate change's impacts on U.S. agriculture

by Kerry Halladay, Associate Editor

— Environmental group uses release to push anti-meat narrative

Another day, another massive report from an international group.

At an astounding 2,559 pages collectively (chapters plus technical summary, not counting appendix materials), the International Panel on Climate Change (IPCC) released its most recent installment on the state of climate change in the world.

Though the voluminous work covered a myriad of literally global topics, its impact on agriculture was a frequent theme. And unsurprisingly, one environmental group’s response to the report was entertainingly agriculturally-themed—cherry-picking—though they seemed to be reaching for fruit that wasn’t there.

IPCC’s second working group released its immense report, “Climate Change 2014: Impacts, Adaptation, and Vulnerability,” last Monday. The report was compiled by 243 lead authors and 66 review editors from 70 countries, as well as 436 contributing authors from 54 countries. The purpose of the report was to identify what impacts climate change has already had, where human and ecological vulnerabilities lie under a number of projections for the future, and what adaptations are available, as well as impediments to those adaptations.

Agricultural topics came up frequently, particularly given agriculture’s centrality to human well-being and the problem of food insecurity around the world. But, unlike most climate change-themed works, the focus was on how climate change is impacting agriculture rather than the other way around.

“Based on many studies covering a wide range of regions and crops, negative impacts of climate change on crop yields have been more common than positive,” noted the report’s summary for policy makers (not included in the above page count). “Climate change has negatively affected wheat and maize [corn] yields for many regions and in the global aggregate.”

The summary also noted that some areas have also seen negative crop yields for soybeans and rice, though the negative impacts in some areas have been balanced out on a global scale with yield improvements in other regions. According to summary estimates, on average the global corn yield has declined roughly 1 percent each decade from 1960-2013. Wheat yields were estimated to have lost an average of 2 percent per decade, again on a global scale. It is worth noting, however, that these estimates were drawn from only 12 and 18 data points, respectively.

Climate change and the U.S.

The report addresses specific regions of the earth, noting that regional differences in geography, ecology, society, and so many other elements demand a regional mindset. For the U.S., the ongoing droughts, unusual heat and increased frequency and severity of wildfires in the West, the excessive precipitation in the Midwest, and the uncharacteristically large/intense hurricanes and similar coastal storms on the East Coast were cited as impacts of climate change.

At least for the topic of droughts, it is interesting to note the report said “it is not possible to attribute changes in drought frequency in North America to anthropogenic [human-caused] climate change…” All of those extreme weather events have had and continue to have negative impacts on agriculture and/or food access (and thereby food markets) by people in affected areas. The report also points out that negative effects on the agriculture of North America can have wide global impacts given the strong agricultural exports of particularly the U.S., and Canada and Mexico to lesser degrees.

“Together with climate hazards such as higher sea levels and associated storm surges, more intense droughts, and increased precipitation variability, these changes are projected to lead to increased stresses to water, agriculture, economic activities and urban and rural settlements,” read the chapter on North America (chapter 26).

The report notes that, while some ability to be proactive to extreme weather events exists technologically, so far responses to things like massive drought, wildfires and flooding has been reactive and that infrastructures to deal with such issues are “in many cases deteriorating, thus more vulnerable to extremes…” It also points out that, counter to the global average yield changes mentioned above, the U.S. and Canada have and are projected to have continued yield increases in major crops, and be among the few places where climate change may positively affect yields in the short term.

“Historic yield increases are attributed in part to increasing temperatures in Canada and higher precipitation in the U.S.,” says the report at one point, though it also points out that increases in either/or temperature and precipitation would reverse the benefit.

“The North American agricultural industry has the adaptive capacity to offset projected yield declines and capitalize on opportunities under 2 [degrees Celsius over the pre-industrial average benchmark] of warming.” Without adapting, it projects corn yield losses between 6-14 percent, though in what span of time it did not make clear.

Though far more detailed and wide-ranging in the report itself, recommended strategies for adapting to climate change included:

• Regionally-adapted crop varieties more tolerant of heat or precipitation extremes, including genetically modified varieties;

• Crop diversification;

• Adopting low- or no-till practices to reduce soil erosion and protect plants from extreme precipitation, among other benefits;

• Planting legumes and implementing weed management on pastures to improve productivity and soil carbon sequestration; and

• Planting shade perennials to help retain soil moisture and contribute to local cooling.

Cherry-picking for propaganda

There are some entertaining details worth noting in the tall stacks of the report’s 2,559 pages. Out of its 30 chapters and preceding technical summary, only 14 mention the topic of agriculture. In almost all cases, this discussion is restricted to crops. Only six out of the 30 chapters touch on livestock (not including fisheries or aquaculture), and of those, only one chapter—chapter nine, with all of 74 pages—discusses cattle, grazing, or meat consumption. Chapter nine’s page count is 2.9 percent of the overall report and includes the only mention of meat consumption found by WLJ, and even then it was only a fleeting single mention.

This detail didn’t stop the environmental group Center for Biologic Diversity (CBD) from using the report’s release as an opportunity to denounce meat consumption.

“The Intergovernmental Panel on Climate Change’s latest report today highlights the increasing threat from rising global meat and dairy consumption to limiting global warming, especially as the world population continues to grow,” said the group in a press release issued last Monday, the same day as the 2,559-page report was released to the public.

Despite searching through all of the 31 electronic documents that compose the report’s technical summary and 30 chapters, WLJ could find— using keyword searches— only one mention of “meat,” no mentions of “dairy,” only two mentions of “cattle,” and nothing in the sections including the words “agriculture” or “livestock,” which support the claims made by CBD.

Interestingly, the CBD response to the IPCC report—titled “International Climate Report: Cutting Meat Consumption Key to Reducing Emissions”— shifts quickly to discussing the results of a study out of Sweden’s Chalmers University of Technology that, aside from the same day of release and vaguely similar topics, had no connection to the IPCC report.

However, the Swedish study—“The importance of reduced meat and dairy consumption for meeting stringent climate change targets” by lead researchers Fredrik Hedenus, Stefan Wirsenius, and Daniel J. A. Johansson—contained findings more in line with CBD’s usual narrative.

“We have shown that reducing meat and dairy consumption is key to bringing agricultural climate pollution down to safe levels,” reported study author Fredrik Hedenus in the university’s translated news release.

“These emissions can be reduced with efficiency gains in meat and dairy production, as well as with the aid of new technology,” added co-author Stefan Wirsenius. “But the potential reductions from these measures are fairly limited and will probably not suffice to keep us within the climate limit, if meat and dairy consumption continue to grow.”

As mentioned, the IPCC report said next to nothing on the topic of meat and dairy consumption. In fact, the mentions of meat consumption and cattle were contained in discussions about the impact climate change currently has and will likely have on cattle ranchers in the future, and even then, the scope was mostly on pastoralists in African countries.

“As extensive livestock production is associated with semi-arid areas marginal for cropping, some authors project shifts toward livestock production under climate change. Modeled data from across Africa on the net income per unit of land from crops and different livestock species, show that farmers are more likely to keep livestock, compared to crop cultivation, as temperatures increase and as precipitation decreases. Within livestock production, beef production will decline and sheep and goat production increase. Large-scale commercial beef cattle farmers are most vulnerable to climate change, particularly since they are less likely to have diversified.”

It should be noted however that the purpose of the report was to identify the impacts of climate change, where vulnerabilities lie in relation to climate change, and what societies can do to mitigate those impacts and vulnerabilities in the future. It was not within the scope or intention of the report to cover causes of climate change. — Kerry Halladay, WLJ Editor