By Rob Mitchum // December 19, 2013
This week, the prestigious journal Proceedings of the National Academy of Sciences published a special section of 11 papers describing the global impacts of climate change. The massive body of research was the work of the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), an international collaboration of over 30 research teams, including the Computation Institute. CI fellow and RDCEP researcher Joshua Elliott was lead author on a study on the impact of climate change upon freshwater supply, irrigation, and agriculture, and co-author on many of the other studies. The alarming “highlights” of the research were described this week at The Guardian by environment blogger Nafeez Ahmed:
Water scarcity in turn will have a dramatic impact on agriculture. Another study in the PNAS collection combining climate, agricultural and hydrological models warns that freshwater shortages could double climate change’s debilitation of global food crop yields.
Current agricultural models estimate that climate change will directly reduce food production from maize, soybeans, wheat and rice by as much as 43 percent by the end of the 21st century, encompassing a loss of between 400 and 2600 petacalories of food supply. But incorporating hydrological models reveals that when accounting for the decline of freshwater availability, there would be an additional loss of 600 to 2900 petacalories – potentially wiping out quantities equivalent to the total present-day food supply.
Such devastating potential losses could, however, be ameliorated by more efficient use of available surplus freshwater. The paper recommends “increases in irrigation capacity and efficiency” to be complemented by “efforts to increase water use efficiency and soil conservation in rainfed systems as well, which have a demonstrated capacity to boost crop yields without further exploiting freshwater resources in rivers and aquifers.”
In addition to The Guardian coverage, you can read about the ISI-MIP special section and its research from several participating institutions:
Recognizing the Elephant in the Room: Future Climate Impacts across Sectors, Potsdam Institute for Climate Impact Research
Climate change puts forty percent more people at risk of absolute water scarcity: study, Potsdam Institute for Climate Impact Research
Identifying climate impact hotspots across sectors, Potsdam Institute for Climate Impact Research
How will climate change affect people around the world?, International Institute for Applied Systems Analysis
New studies map future climate impacts across sectors, International Institute for Applied Systems Analysis
Declining crop yields and increasing food prices? Modelling the effects of climate change on agriculture, Institute of Development Studies
Major economic models on climate change and agriculture point in same direction, but differ on magnitude of effects, International Food Policy Research Institute
Multi-Model Assessments Predict Effects of Climate Change on Agriculture, The Earth Institute at Columbia University
4 degree temperature rise will end vegetation ‘carbon sink’, University of Cambridge
Climate change causes increased water scarcity globally, Norwegian Water Resources and Energy Directorate