A J-WAFS Expert Workshop 8-9 May 2018 MIT Endicott House, Dedham, Massachusetts

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1 Climate Change, Agriculture, Water, and Food Security: What We Know and Don t Know A J-WAFS Expert Workshop 8-9 May 2018 MIT Endicott House, Dedham, Massachusetts Summary The MIT Abdul Latif Jameel World Water and Food Security Lab will conduct a two-day workshop for expert review of the current understanding of possible impacts of climate change on agriculture and food security. Both climate s impact on agriculture and agriculture s impact on climate will be considered, including changes to water availability, changes to food crop productivity, and changes in GHG emissions driven by food production. Climate change is projected to place significant pressures on water supplies and will affect rainfall amounts and intensities, potentially restricting water availability for agriculture. Heat stress has a deleterious effect on crop production, and an increase in extreme temperature events limits the productive capability of current commercial plant species on which the population depends for food security. Climate impacts are geography specific, and solutions for mitigating climate change are region dependent. Similarly, meeting the needs for food security must be contextualized by the prevailing economic, political, social, cultural and sovereignty conditions within countries. The objective of the workshop will be to identify what we know with confidence and questions that should be high priority for future research. The workshop will be an invitation-only gathering of experts from outside and inside MIT. Select graduate students and postdocs will also be invited. The results will be published in an appropriate format. Problem statement Measured data show that global temperatures, as well as greenhouse gas (nitrous oxide N 2 O; carbon dioxide CO 2 ; methane CH 4 ) emissions are rising. (See Figures below taken from the Greenhouse Gas Working Group, 2010). A changing climate is leading to more occurrences of extreme events such as droughts (moisture deficits) and floods (moisture surpluses), which have a negative impact on crop growth and yields. Plants require an optimum soil-water-air environment in the root zone to maintain physiological response to growth, photosynthetic functions, and productive vegetative capacity for high yield response. Rising air temperatures also have a deleterious effect on crop production, as heat stress limits the optimum productive capability of our current commercial plant species on which the population depends for food security. A changing climate is also affecting other aspects of crop production such as increased pests and disease in some situations, changes and even losses in biodiversity in some environments, and major disruptions due to extreme storm events, such as the recent decimation by Hurricane Maria of Puerto Rico s agricultural crops, livestock, and associated infrastructure. Agriculture is estimated to contribute approximately 20-25% of total greenhouse gas (GHG) emissions. In terms of on-farm production, most of these emissions are due to methane releases from intensive livestock 1

2 production, as well as from flooded paddy rice production, nitrous oxide fluxes from nitrogen fertilizer applications, and CO 2 emissions from farm machinery, irrigation pumps etc. Off-farm emissions (transportation, food processing, distribution, retailing etc.) are much more difficult to quantify and attribute to the agriculture and food sectors but are considered to be substantial as well. We also know that C3 crops such as wheat and rice can benefit from higher CO 2 emissions, and that higher CO 2 fluxes increase water use efficiency. However, on the other hand, CO 2 increases can affect tropospheric ozone, thereby reducing crop productivity. A number of other potential linkages have been suggested. As an example, one study suggested that increased concentrations of CO 2 will likely limit the effectiveness of some herbicides, which will in turn decrease crop yields due to higher weed infestations. These complex interactions need to be better understood, if we wish to mitigate climate change impacts. While agriculture is a contributor to overall GHG emissions, the sector also offers potential to mitigate climate change. For example, field management practices and cropping systems could be designed to sequester more soil carbon. In addition to reducing atmospheric carbon loadings, increased sequestration of soil carbon can improve soil quality, increase crop yields, improve soil water storage, and contribute to groundwater recharge. This potential should be further explored and better studied. An added advantage of improved crop management, as an important component of sustainable landscape management, is that biodiversity is likely to be better protected, and hence offer natural biological resistance to pest and disease invasion as well as better support of ecosystem functions for pollinator survival. Although numerous studies have considered climate projections into the next years, much uncertainty remains around the models (GCMs, RCMs). Accurate projection remains very difficult for various parts of the world, leaving us with insufficient confidence in current capacity to project, and design responses to, likely changes in precipitation patterns and temperatures. In turn, it is difficult to project with confidence how these changes will affect the availability of water supplies for agriculture and crop production. Water is critical to agriculture, and there is concern that there could be increased flooding of agricultural lands in some parts of the world, and increased frequency of droughts in other parts. See Annex 1 (taken from the IPCC 2014 Fifth Assessment Report). Therefore, irrigation and drainage infrastructure will need to be adapted to handle both water scarcity, as well crop damage due to more frequent flood events. 2

3 Purpose of the workshop The IPCC 2014 Fifth Assessment Reports all concur that many climate model predictions have large degrees of uncertainty. Many of the climate induced risks which are identified carry varying levels of confidence (high, medium, low). In order to obtain a technically rigorous assessment of the current state of knowledge of climate change impacts on agriculture and food security, as well as to identify areas where MIT itself could make substantial scientific and technical contributions, MIT J-WAFS is convening a two-day expert workshop on the Impacts of Climate Change on Agriculture and Food Security, to be held May 8-9, The workshop will have three main objectives: 1. Bring together MIT researchers and other experts in the field to provide a state-of-the art assessment of what we know and what we don t know about the impacts of climate change on agriculture and the impacts of agriculture on climate change; 3

4 2. Define key research questions that can lead to innovative solutions based on sound science which can better position crop production to meet the food security challenges in the face of climate change; 3. Establish some short-term climate scenario assessments, based on robust global change modeling, that can provide inputs to policy development on mitigation of climate change impacts to agriculture, water and food production. Given the wide-reaching subject and broad range of potentially relevant research, the workshop will address a more limited and focused set of topics that build on areas of expertise and research interests of MIT faculty and researchers. These include: impacts of climate on agriculture and vice-versa, climate modeling and application to agriculture, natural resources and climate policy, big data analytics, engineering of soil-plant systems to cope with climate change and climatic extremes, and managing land and water resources in light of climate change to achieve food security. Workshop format The content of the workshop will be grounded by a set or presentations summarizing what is known from the science, where there are disagreements, what scientific questions remain unanswered, and what the knowledge gaps are. Leading researchers from outside and inside MIT will be invited to deliver these presentations on their respective areas of expertise. Some seven topics are proposed over the two-day period (see Table 1 below). There will be co-presenters for each topic, and then a moderated discussion held after each topic. In addition to these seven topics, we propose to have a speaker lead off the workshop on day 1, addressing the broader economic, cultural, social and political forces that shape global security and which impact climate change. On Day 2 there will be a closing discussion summarizing the key findings of the workshop, and an identification of the knowledge gaps and potential areas for collaborative research. MIT graduate students and postdocs who have been invited to attend the workshop will take notes on all the presentations and discussions, and will use these together with the slide decks to assist the speakers and organizers in developing a report to be published after the workshop. The report will either be an edited volume from a major publisher or a summary paper for peer-reviewed journal submission. The workshop presentations will open to faculty, staff, and students at MIT, by application for registration. Registration capacity is to be determined by the size of the venue (MIT Endicott House conference center). Some potential questions for discussion by the speakers or in the breakout sessions: 1. What are the major impacts of crop production on climate change? How well are these understood? What are the trends and what are the drivers? What are the big dials available for us to turn in mitigating such impacts? 2. What do we know about the impact of greenhouse gas emissions and atmospheric processes on the yields of major cereals and grain crops? 3. How will the availability of water for agriculture change with future climate, and how will this affect the balance between irrigated and rain-fed agriculture? How will agriculture adapt to extreme climatic conditions (floods and droughts)? What types of water management systems could improve water use efficiency by crops during periods of water scarcity and drought? 4

5 4. How can we innovate food production systems to use less water, less land, less carbon, and less energy to support global food requirements that are estimated to increase by % over the coming decades, while still reducing GHG emissions? 5. How can we better simulate the effects of climate change on agricultural production? What are the limitations of current models? Are there new opportunities in data science and data analytics to improve our crop models and climate predictions? 6. What near-term gains can be made through crop genetic improvement and other biological technologies for heat and drought tolerance, increased soil carbon sequestration, reduced nitrogen fertilizer usage, and enhanced biological nitrogen fixation in crop production? What is the potential to regulate soil nitrogen cycling, to increase nitrogen use efficiency in crops and reduce N 2 O emissions while ensuring C:N ratios that favor soil health and crop production? References Greenhouse Gas Working Group Agriculture s role in greenhouse gas emissions & capture. Greenhouse Gas Working Group Rep. ASA, CSSA, and SSSA, Madison, WI. IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp. Porter, J.R., L. Xie, A.J. Challinor, K. Cochrane, S.M. Howden, M.M. Iqbal, D.B. Lobell, and M.I. Travasso, 2014: Food security and food production systems. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp

6 Annex 1. Climate induced risks and adaptation needs (IPCC, 2014) 6