Title: Is current irrigation sustainable in the United States? An integrated assessment of climate change impact on water resources and irrigated crop yields

Abstract

While climate change impacts on crop yields has been extensively studied, estimating the impact of water shortages on irrigated crop yields is challenging because the water resources management system is complex. To investigate this issue, we integrate a crop yield reduction module and a water resources model into the MIT Integrated Global System Modeling framework, an integrated assessment model linking a global economic model to an Earth system model. We assess the effects of climate and socioeconomic changes on water availability for irrigation in the U.S. as well as subsequent impacts on crop yields by 2050, while accounting for climate change projection uncertainty. We find that climate and socioeconomic changes will increase water shortages and strongly reduce irrigated yields for specific crops (i.e., cotton and forage), or in specific regions (i.e., the Southwest) where irrigation is not sustainable. Crop modeling studies that do not represent changes in irrigation availability can thus be misleading. Yet, since the most water-stressed basins represent a relatively small share of U.S. irrigated areas, the overall reduction in U.S. crop yields is small. The response of crop yields to climate change and water stress also suggests that some level of adaptation will be feasible, like relocatingmore » croplands to regions with sustainable irrigation or switching to less irrigation intensive crops. Finally, additional simulations show that greenhouse gas (GHG) mitigation can alleviate the effect of water stress on irrigated crop yields, enough to offset the reduced CO₂ fertilization effect compared to an unconstrained GHG emission scenario.« less

Authors:

Blanc, Elodie  ^[1];

• Search DOE PAGES for author "Blanc, Elodie"
• Search DOE PAGES for ORCID "0000-0003-1997-8212"

Caron, Justin  ^[2];

• Search DOE PAGES for author "Caron, Justin"
• Search DOE PAGES for ORCID "0000-0002-8080-4724"

Fant, Charles ^[1]; Monier, Erwan  ^[1]

• Search DOE PAGES for author "Monier, Erwan"
• Search DOE PAGES for ORCID "0000-0001-5533-6570"

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+ Show Author Affiliations

1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Joint Program on the Science and Policy of Global Change
2. HEC Montreal, QC (Canada). Dept. of Applied Economics

Publication Date:

Tue Jun 27 00:00:00 EDT 2017

Research Org.:

Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER); USEPA

OSTI Identifier:

1424381

Grant/Contract Number:  

FG02-94ER61937; XA-83600001

Resource Type:

Accepted Manuscript

Journal Name:

Earth's Future

Additional Journal Information:

Journal Volume: 5; Journal Issue: 8; Journal ID: ISSN 2328-4277

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; 29 ENERGY PLANNING, POLICY, AND ECONOMY; 60 APPLIED LIFE SCIENCES; crop yields; irrigation; climate change; mitigation policy