title: Food for thought: lower-than-expected crop yield stimulation with rising CO2 concentrations.
abstract: Model projections suggest that although increased temperature and decreased soil moisture will act to reduce global crop yields by 2050, the direct fertilization effect of rising carbon dioxide concentration ([CO2]) will offset these losses. The CO2 fertilization factors used in models to project future yields were derived from enclosure studies conducted approximately 20 years ago. Free-air concentration enrichment (FACE) technology has now facilitated large-scale trials of the major grain crops at elevated [CO2] under fully open-air field conditions. In those trials, elevated [CO2] enhanced yield by approximately 50% less than in enclosure studies. This casts serious doubt on projections that rising [CO2] will fully offset losses due to climate change.
authors.affiliation: Department of Plant Biology, University of Illinois at Urbana Champaign, 1201 West Gregory Drive, Urbana, IL 61801, USA. stevel@life.uiuc.edu
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Long
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Ainsworth
authors.forename: Andrew D B
authors.initials: AD
authors.lastname: Leakey
authors.forename: Josef
authors.initials: J
authors.lastname: Nösberger
authors.forename: Donald R
authors.initials: DR
authors.lastname: Ort
mesh_terms: D001272:Atmosphere; D018533:Biomass; D002245:Carbon Dioxide; D018556:Crops, Agricultural / Q000254:growth & development* / Q000378:metabolism; D005308:Fertilizers; D005544:Forecasting; D015201:Meta-Analysis as Topic; D009584:Nitrogen; D010126:Ozone; D010788:Photosynthesis; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism; D045868:Sorghum / Q000254:growth & development / Q000378:metabolism; D013025:Glycine max / Q000254:growth & development / Q000378:metabolism; D013696:Temperature; D014908:Triticum / Q000254:growth & development / Q000378:metabolism; D014867:Water; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism
chemical_list: D005308:Fertilizers; D014867:Water; D002245:Carbon Dioxide; D010126:Ozone; D009584:Nitrogen