ANGUSJournal. March 2013

Transcription

1 206 ANGUSJoural

2 More Climate Chage Comig Be aware beef productio may chage, too. by Barb Baylor Aderso G lobal climate chage talk has bee aroud for years, but the 2012 drought may have provided just eough tractio for producers to pay closer attetio to what experts are sayig: Without chages i huma behavior, agriculture faces additioal stress that may require a shift i maagemet practices. Climate chage is real, ad extreme weather evets will become more commo, says Do Wuebbles, Uiversity of Illiois atmospheric scieces professor. Wuebbles shares the 2007 Nobel Peace Prize for his work with the Itergovermetal Pael o Climate Chage. We see may idicators the climate is chagig, ad evidece clearly idicates it primarily is due to huma activities especially burig of fossil fuels ad correspodig carbo dioxide ad other greehouse gas emissios. Wuebbles cites results from the U.S. Natioal Climate Assessmet, which i its 2009 report foud that climate chages uder way i the Uited States are projected to grow ad a icreasig tedecy for icreasigly warm icreasig likelihood for heat waves ad fewer cold icreasig amout of raifall comig as itese risig sea level ad chages i river rapidly retreatig glaciers ad thawig loger growig loger ice-free seasos i ocea, lakes ad rivers ad earlier sowmelt. Geeral agriculture effects Beef productio questios Projectig the impact of climate chage o beef productio is still a work i progress. Wuebbles says part of the challege is uderstadig how cattle might respod to temperature ad heat stress chages. CONTINUED ON PAGE 208 ANGUSJoural 207 PHOTO BY SHAUNA ROSE HERMEL The U.S. is breakig twice as may heat as cold records, ad more heat waves are likely, he cofirms. We will face more drought ad flood risk ad have more large precipitatio evets. More specifically, Wuebbles says data from the last 50 years idicate the Uited States has see a greater umber of floods i the Midwest ad Northeast ad fewer floods i the Southwest. Because of a warmer atmosphere, such treds may cotiue. Drought has become more commo i the West ad Southeast. Climate chage geerally will alter our ability to achieve food security, he says. We will see direct effects o water, temperature, eergy ad weather extremes. Idirect effects o food security iclude chages with isects, weeds, diseases ad food quality. For example, Wuebbles says weeds respod more to carbo dioxide tha crops, which could icrease their presece. Likewise, overall crop yields are likely to decrease by 2050 because yield potetial is especially sesitive to high temperatures durig polliatio ad the grai fill period. The exceptio could be a icrease i soybea yield potetial i the Midwest. Maximum yields are associated with water availability. No drought lies of ay crop exist that ca yield as much as a well-watered cultivar, he says. A recet study from Staford Uiversity idicates all of the improvemets we have made geetically i crops over the last 10 years may have bee totally offset by chages i climate. That may lead to a egative impact o crop yields evetually, as well as affect livestock feedig capabilities ad the ability for beef producers to market aimals efficietly.

3 More Climate Chages Comig CONTINUED FROM PAGE 207 The Natioal Climate Assessmet ad Developmet The risig icidece of weather extremes will have icreasigly Committee (NCADAC), a 60-perso federal advisory committee, egative impacts o crop ad livestock productivity because critical has oversee recet developmet of a draft climate assessmet thresholds are already beig exceeded. report ( for the third Natioal Climate Agriculture has bee able to adapt to recet chages i Assessmet (NCA). The report is ope for public review ad commet however, icreased iovatio will be eeded to esure the rate of util April 12, The Natioal Academies of Scieces also is adaptatio of agriculture ad the associated socioecoomic system reviewig the report, which will be submitted to the White House ad ca keep pace with future climate chage. Cogress after completio i Climate chage effects o agriculture will have Withi the draft report, agriculturecosequeces for food security both i the Uited The U.S. is breakig chapter coveig lead authors Jerry States ad globally, ot oly through chages i twice as may heat as Hatfield, USDA plat physiologist, ad Gee crop yields, but also chages i the ways climate Takle, Iowa State Uiversity Climate Chage affects food processig, storage, trasportatio ad cold records, ad more Program director, ad others outlie several retailig. key messages: Withi the report, the authors workig i heat waves are likely. collaboratio with other scietists, submit Climate disruptios to agricultural Do Wuebbles productio have icreased i the recet climatic coditios could affect beef productio i past ad are projected to icrease further terms of aimal health, growth, reproductio, disease durig the ext 25 years. By mid-cetury ad beyod, these ad pests, as well as through feed-grai, pasture ad forage-crop impacts will be icreasigly egative o most crops ad livestock. productio, availability ad price. May agricultural regios will experiece declies i crop ad Livestock will be at icreased risk of exposure to extreme livestock productio from icreased stress due to weeds, diseases, evets. Projected icreases i the occurrece of extreme heat evets isect pests ad other climate chage-iduced stresses. will expose productio systems to coditios exceedig Curret loss ad degradatio of critical agricultural soil ad water thresholds for beef cattle maaged i extesive outdoor facilities, the assets by icreasig extremes i precipitatio will cotiue to report reads. Withi physiological limits, aimals ca adapt to ad challege both rai-fed ad irrigated agriculture uless iovative cope with gradual thermal chages, though shifts i thermoregulatio coservatio methods are implemeted. may result i a loss of productivity. Lack of prior coditioig Fig. 1: Thermal heat idex: livestock Beef cattle i the Midwest are likely to be subject to ever-icreasig cocers about heat effects. The higher emissios time progressio is a worst-case sceario illustratio of the possible impact. Should humas make chages i behavior, the lower emissios sceario is more likely. Source: Do Wuebbles. 208 ANGUSJoural

4 Fig. 2: Midwest growig seaso is legtheig to rapidly chagig or adverse weather evets, however, ofte results i catastrophic deaths. The authors ote that deviatios from optimum aimal core body temperature ca cause disruptios i performace, productio ad fertility, ad limit beef productio. For cattle bred durig sprig ad summer moths, exposure to high temperatures reduces coceptio rates. Productio is more affected by the umber of days of extreme heat tha by icreases i average temperature. Elevated humidity exacerbates the impact of high temperatures o aimal health ad performace, the report reads. Meat aimals are maaged for a high rate of weight gai, which icreases their potetial risk whe exposed to high-temperature coditios. Exposure to heat stress causes problems for aimals, ad exposure to high temperature evets ca be costly. Fig. 4: Temperature projectios: Higher Midwest temperature chages (compared to ) i a high-emissos sceario. Prepare for possible chages While Wuebbles ad other climate-chage experts do ot have a crystal ball to predict the magitude of future chages, they do offer some sese of the risks associated with the types of chages that may occur ad have suggestios that may help beef producers pla for the log ru. Based o projected climate chage impacts, U.S. agricultural systems may have to udergo more trasformative chages to remai productive CONTINUED ON PAGE 210 Fig. 3: Cotiguous U.S. temperature treds U.S. average temperature has rise more tha 2 F durig the past 50 years. ANGUSJoural 209

5 More Climate Chage Comig CONTINUED FROM PAGE 209 ad profitable i the log term. Research ad developmet of sustaiable atural resource maagemet strategies (may offer) adaptatio optios for U.S. agriculture. Strategies, such as coversio to itegrated crop-livestock farmig, may reduce evirometal impacts, improve profitability ad sustaiability, ad ehace ecological resiliece to climate chage i U.S. livestock productio systems, ote the report authors. Beef producers should be aware that climate chage ca affect ot oly their livelihoods, but their families ad lifestyles, i may ways, says Wuebbles. We may ot kow eough to make specific recommedatios yet, but as scietists we will work to get to the truth. Wuebbles welcomes costructive iput, ad ecourages producers to cotact him with climate chage questios the idustry eeds aswered. He ca be reached at or wuebbles@illiois.edu. Editor s Note: Barb Baylor Aderso is a freelacer based out of Edwardsville, Ill. She is a former director of the Natioal Juior Agus Board. 210 ANGUSJoural Fig. 5: Midwest: Severe precipitatio evets likely to icrease (ew CMIP5 aalyses) Percet chage i aual fractio of simulated precipitatio totals above 99th percetile, Midwest, 9-year ruig average Historical ad projected chages i the amout of precipitatio fallig i the top 1% of evets.