EITZINGER, J.

NAYLOR, R. E. L.

ORLANDINI, S.

STEFANSKI, R.

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CLIMATE CHANGE AND AGRICULTURE PAPERClimate change and agriculture: introductory editorialJ. EITZINGER1, S. ORLANDINI2, R. STEFANSKI3 AND R. E. L. NAYLOR4*1Institute of Meteorology, BOKU – University of Natural Resources and Applied Life Sciences, A-1190 Vienna,Austria2Department of Plant, Soil and Environmental Science, University of Firenze, 50144 Firenze, Italy3World Meteorological Organization, Geneva, Switzerland4Trelareg Consultants, Aberdeen, Scotland, UK(Revised MS received 22 June 2010; Accepted 23 June 2010)There seems to be little doubt that the global climate ischanging, partly due to natural factors, and in partdue to forcing by human activities. However, there arestill uncertainties about the extent to which humanactivity (including agricultural activity) has contri-buted to the current changes and could inﬂuence thefuture climate.Inevitably, climate and its variability, including theongoing current changes at various spatial and tem-poral scales, must impact on agricultural activities. Amajor challenge for the agricultural industry world-wide is to feed the world population that has beenprojected to increase by 50% from 6 billion in 2000 to9 billion in 2050. Most of the increase occurred in theless developed countries, where the current food pro-duction is often low. But, although the proportion ofhungry people in the world is far below that of 1970,FAO’s current estimate of the number of under-nourished people in the world in 2008 was 915 million,the highest over the past 30–40 years (FAO 2009).History suggests that we can be optimistic aboutachieving appropriate increases in food production.Nevertheless, agriculture must adapt to a changing,and probably more variable, climate and simulta-neously reduce emissions and other human impacts,which contribute to global warming. We need todevelop and implement farming systems that producemore, from lower inputs, and that do not predjudicethe future (i.e. are more sustainable) than the currentsystems.A key focus of much current research around theworld is to predict future changes in climate and tosuggest how these changes will curtail current agri-cultural systems at individual locations. Thus, theJournal of Agricultural Science, Cambridge hasdecided to inaugurate a ‘special topic’ of ClimateChange and Agriculture. In this issue, we launch theseries that will continue in future issues. The series willconcentrate mainly on the effects of changing climateon agricultural activity but will also consider theimpacts of agriculture on climate.One group of papers deals with estimating climatechange and documenting or predicting its effects oncurrent agricultural systems, activity and outputs aswell as estimating or predicting agricultural impactsfrom future climate change. The variability in climate,i.e. changing weather conditions from season toseason, has a signiﬁcant impact on agricultural pro-ductivity. There are several seasonal climate vari-ations, such as the El Nino Southern Oscillation or theNorth Atlantic Oscillation, which are important indetermining seasonal weather patterns and can impacton crop yields. Studying how current climatic vari-ability inﬂuences crop yields is not only important inproviding a baseline for estimation of future impacts,but it can also give insights into potentially useful cropprediction methods. Climate factors represent one ofthe main inputs for plant growth and have a directeffect on many plant physiological processes such asthe onset and duration of phenological stages. Overthe past decades, temperatures have been increasingand this has led to earlier start dates of crop stages andeven shortening the duration of stages for certainspecies. This has implications for determining whichcrop varieties farmers can best grow at a certainlocation. Varieties developed or adapted to a certainlocation over the past 30 years may not be the bestvarieties to grow in the future. Integrating cropmodelswith climate change scenarios can provide importantinformation on whether farmers could or shouldreplace the current crops or crop varieties with onesgrown elsewhere in a region or continent, whethermore research is needed to develop new varieties or* To whom all correspondence should be addressed.Email: r.e.l.naylor@abdn.ac.ukJournal of Agricultural Science (2010), 148, 499–500. © Cambridge University Press 2010doi:10.1017/S0021859610000481499at https:/www.cambridge.org/core/terms. https://doi.org/10.1017/S0021859610000481Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 07:41:32, subject to the Cambridge Core terms of use, availablewhether to use crops from elsewhere in the world.Another important area of study is the altered impactof pests and diseases on crops in a changing climate.Climatic factors also alter many soil processes such asorganic balances, nutrient cycling, soil erosion, leach-ing, salinization and others, leading to changing soilconditions that again can change the long-term yieldpotential for crops. Finally, climate or weather ex-tremes can damage the realization of crop-yieldpotential and any change of frequency of extremescan increase agricultural production risks signiﬁ-cantly. Adding these aspects to crop-modelling sys-tems increases the demand for higher resolution datain the spatial and temporal scales.A second group of papers concentrates on climatechange with respect to the altered water availabilityand its use. Climate changes modify rainfall, evapor-ation, runoff and soil moisture storage, which in turnaffect plant growth and development. The occurrenceof insufﬁcient moisture during ﬂowering, pollinationand grain-ﬁlling is harmful to most crops (e.g. grain,maize, soybean and wheat). Increased evaporationfrom the soil and increased transpiration from theplants cause drought stress, resulting in an increasedneed for crop varieties with greater drought tolerance.The demand for water for irrigation is projected to risein a warmer climate, increasing the competition be-tween agriculture and urban as well as industrial usersof water. Falling water tables and the resultingincrease in the energy needed to pump water makesthe practice of irrigation more expensive, while morewater will be required per unit area under drierconditions, all resulting in the generation of moregreenhouse gas emissions. Peak irrigation demandsare also likely to rise due to more severe heat waves.Additional investment for dams, reservoirs, canals,wells, pumps and piping may be needed to developirrigation networks in new locations or to maintainthe existing irrigation systems. Changes in soil wateravailability alter soil salinization processes in bothirrigated and dry land cropping systems, with eitherbeneﬁcial or problematic outcomes depending on thesystem and climate changes. Altered patterns of rain-fall lead to additional rainfall in other areas, pro-ducing higher rainfall intensities. This can lead toenhanced soil erosion and ﬂooding. In addition, invery seasonal climates there is the possibility of im-proved water storage and water status of soils incurrently drier areas. Increases in humidity may alsochange the incidence and severity of plant diseases andof pest occurrence.A third group of papers considers our reactions tochange, how we might mitigate the effects and how wemight adapt to the possible future. Adaptation in-cludes human activities, which adds some complexityto the challenge. In agriculture, signiﬁcant differencesin agricultural production conditions within regionsor countries reﬂect differences in natural productionresources, production risks and limitations as well associo-economic conditions. Additionally, severallevels of stakeholders can be identiﬁed, operating atdifferent spatial regimes and scales from the policylevel to the farm level. Adaptation to climate vari-ability and change requires attention at different timescales, so as to develop measures for short-term(tactical) or long-term (strategic) responses. Thismakes it necessary to distinguish between spatial andtemporal scales of adaptation studies in order to be ofrelevance for a particular challenge or stakeholder.Regional studies addressing local conditions are ofspecial importance for local stakeholders or farmers,whereas studies that are carried out at larger spatialscales are more relevant for the policy level (e.g. toensure food security). Thus, the research for develop-ing the adaptation measures for agriculture is still atthe starting point, and this series of papers wouldcontribute to the knowledge fund.Since 1905, the Journal of Agricultural Science,Cambridge has documented the research of ‘agricul-tural’ topics, which has involved utilizing a broad andever-changing range of disciplines and research en-compassing a range of scales. We believe that climatechange and agriculture is an important topic thatdeserves wider appreciation and discussion. We alsobelieve that the papers in this series (that will bepublished over a number of issues) can provide someevidence to help dispel the clouds of ignorance andmisinformation that exists. Food production andsecurity are vital activities (but in developed countries,all too often unrecognized) and climate change im-pacts on it. If agriculture is to continue the successes ofthe previous ﬁve decades in feeding the expandingworld population in a sustainable way through intothe next 50 years, then it is vital we (a) are aware of thecurrent climate change impacts and likely futureclimate changes, (b) understand the impact of theselikely changes on food production on a regional basisand (c) importantly, suggest the ways in which we canadapt ourselves, our agriculturally exploited speciesand our agricultural systems in order to secure ourfuture food supply. This series aims to support thatendeavour.REFERENCEFAO (2009). The State of Food Insecurity in the World 2009. Rome: FAO.500 J. E I TZ INGER E T A L .at https:/www.cambridge.org/core/terms. https://doi.org/10.1017/S0021859610000481Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 07:41:32, subject to the Cambridge Core terms of use, available

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