Discussion Paper 01015, International Food Policy Research Institute, Washington, DC. Yu, Bingxin, Tingju Zhu, Clemens Breisinger, and Nguyen Manh Hai

A dual model of the effects of climate change and policy on rice yield finds the reduction to be severe, rising to 2.7 million tons by 2050, although intensification and investment in rural infrastructure could mitigate the reduction, the effectiveness will depend on targeting marginalized communities and tailoring to regional variations.

Rice is certainly the most important agricultural commodity in Vietnam, and its production is very closely tied to rural livelihoods. Two thirds of the rural labour force is employed in rice production which covers 75% of total annual harvested area. Rice is also very closely tied to the greater economy, as rapid productivity gains have allowed Vietnam to become the world’s second largest exporter of the commodity. However, regional analyses have shown Vietnam to be among the countries most vulnerable to climate change. Plateauing productivity gains and concerns over climate change beg for closer examination of food security now and until 2050.

A holistic approach to modelling the impact of climate change on rice production in Vietnam is taken, incorporating inputs, technology, policy interventions, and agricultural and water systems. The models are combined to achieve an estimation of the effects on crop yields. Three separate climate data sets are used for thoroughness, and effects are predicted up to 2030 and 2050. Crop production data is obtained from the country-wide Vietnam Household Living Standards Survey (VHLSS).

The effects of climate change are consistent with prior research, with insight provided into the magnitude of change in crop yields. The annual average temperature is found to be increasing, with widely varying precipitation patterns. Furthermore, rising sea levels are expected to significantly expand the inundated area during rainy season, causing problems of salination intrusion. The changes are estimated to lead to a reduction in crop yields of up to 2.7 million tons by 2050, representing a decrease in the range of 4.2% to 12.5%. These figures will vary across regions. For example, climate change should be milder in the Mekong Delta where a significant portion of Vietnam’s rice is cultivated and “the average rice yield is projected to drop by 1.4 to 8.3% by 2030.” On the other hand, the greatest decline in crop yields is predicted in the Central Highlands region.

The findings also suggest that changes in production and policy hold great potential for climate change mitigation. In particular is the potential for crop intensification. Crop yields would benefit by applying more labour, more inputs, and more irrigation, but to varying degrees across the geographically and economically diverse regions of Vietnam. There is also a great need for improvement in infrastructure, such as roads connecting villages to markets and electrification. Finally, less-developed regions and vulnerable populations would benefit most from targeted crop-productivity-enhancing policy.

The authors note that the findings do not include investment in research and development, and cite earlier studies which find government investment to have the greatest impact on agricultural production. This study combines the socioeconomic and environmental circumstances to achieve a better understanding of agricultural productivity and food security.