Impacts of, and Vulnerability and Adaptation to, Climate Change in Water Resources and Agricultural Sectors in China

human development, climate change

Effects of fully open-air [CO2] elevation on leaf photosynthesis and ultrastructure of Isatis indigotica Fort

Traditional Chinese medicine relies heavily on herbs, yet there is no information on how these herb plants would respond to climate change. In order to gain insight into such response, we studied the effect of elevated [CO2] on Isatis indigotica Fort, one of the most popular Chinese herb plants. The changes in leaf photosynthesis,chlorophyll fluorescence, leaf ultrastructure and biomass yield in response to elevated [CO2] (550619 mmol mol–1) were determined at the Free-Air Carbon dioxide Enrichment (FACE) experimental facility in North China. Photosynthetic ability of I. indigotica was improved under elevated [CO2]. Elevated [CO2] increased net photosynthetic rate (PN), water use efficiency (WUE) and maximum rate of electron transport (Jmax) of upper most fully-expended leaves, but not stomatal conductance (gs), transpiration ratio (Tr) and maximum velocity of carboxylation (Vc,max). Elevated [CO2] significantly increased leaf intrinsic efficiency of PSII (Fv’/Fm’) and quantum yield of PSII(WPSII), but decreased leaf non-photochemical quenching (NPQ), and did not affect leaf proportion of open PSII reaction centers (qP) and maximum quantum efficiency of PSII (Fv/Fm). The structural chloroplast membrane, grana layer and stroma thylakoid membranes were intact under elevated [CO2], though more starch grains were accumulated within the chloroplasts than that of under ambient [CO2]. While the yield of I. indigotica was higher due to the improved photosynthesis under elevated [CO2], the content of adenosine, one of the functional ingredients in indigowoad root was not affected

Complex responses of spring vegetation growth to climate in a moisture-limited alpine meadow.

Since 2000, the phenology has advanced in some years and at some locations on the Qinghai-Tibetan Plateau, whereas it has been delayed in others. To understand the variations in spring vegetation growth in response to climate, we conducted both regional and experimental studies on the central Qinghai-Tibetan Plateau. We used the normalized difference vegetation index to identify correlations between climate and phenological greening, and found that greening correlated negatively with winter-spring time precipitation, but not with temperature. We used open top chambers to induce warming in an alpine meadow ecosystem from 2012 to 2014. Our results showed that in the early growing season, plant growth (represented by the net ecosystem CO2 exchange, NEE) was lower in the warmed plots than in the control plots. Late-season plant growth increased with warming relative to that under control conditions. These data suggest that the response of plant growth to warming is complex and non-intuitive in this system. Our results are consistent with the hypothesis that moisture limitation increases in early spring as temperature increases. The effects of moisture limitation on plant growth with increasing temperatures will have important ramifications for grazers in this system

The integrated impacts of climate change, water availability and socio-economic development on China’s food production

Food production in China is a fundamental component of the national economy and driver of agricultural policy. Sustaining and increasing output to meet growing demand faces significant challenges including, climate change, increasing population, agricultural land loss, and competing demands for water. The integrated impacts of climate change, water availability, and other socioeconomic pressures on China’s food production are poorly understood. By linking crop and water simulation models and two scenarios of climate and socioeconomic change (downscaled from IPCC SRES A2 and B2) we demonstrate that under these scenarios out to 2050 the absolute effects of climate change alone are modest and the interactive effects of other drivers are negative, leading to overall changes in total production. Outcomes are highly dependent on socioeconomic development pathways and the effects of CO2 fertilization on crop yields which may almost wholly offset the decreases in production. We find that water availability plays a significant limiting role on potential cereal production. Per capita cereal production falls in all cases, by up to 40% of the current baseline. These results are likely to be optimistic because the CO2 crop yield response function is highly uncertain and the effects of extreme events on crop growth and water availability are likely to be underestimated

Achieving food security in the face of climate change: Final report from the Commission on Sustainable Agriculture and Climate Change

To bring our interconnected food and climate systems within a ‘safe operating space’ for people and the planet, the Commission on Sustainable Agriculture and Climate Change has outlined seven major areas for policy action. Throughout 2011, the Commission worked to harvest the practical solutions detailed in the many recent authoritative reports on food security and climate change. By combining this thorough review of the substantive evidence base with the diverse perspectives and disciplinary expertise, the 13 Commissioners have crafted a succinct roadmap for policy makers. The Commission offers no ‘one-size-fits-all’ solution, but rather points the way forward to foster national, regional and sectoral innovation that can aggregate up to meaningful global change

Achieving food security in the face of climate change: Summary for policy makers from the Commission on Sustainable Agriculture and Climate Change

The Commission on Sustainable Agriculture and Climate Change has reviewed the scientific evidence to identify a pathway to achieving food security in the context of climate change. Food systems must shift to better meet human needs and, in the long term, balance with planetary resources. This will demand major interventions, at local to global scales, to transform current patterns of food production, distribution and consumption. Investment, innovation, and deliberate effort to empower the world's most vulnerable populations will be required to construct a global food system that adapts to climate change and ensures food security while minimizing greenhouse gas emissions and sustaining our natural resource base. Greatly expanded investments in sustainable agriculture, including improving supporting infrastructure and restoring degraded ecosystems, are an essential component of long-term economic development. The sooner they are made, the greater the benefits will be

Rural livelihoods and vulnerability to climate hazards in Ningxia, Northwest China

This study addresses how climate affects the livelihoods of people living in agricultural communities in Ningxia, one of the five autonomous regions in China. The analysis formed part of a vulnerability assessment to contribute to the development of an adaptation strategy for the region. Data were collected through questionnaires and focus group discussions in nine villages, three located in each of three different agro-ecosystems in the region. The survey results showed that drought has been a major hazard impacting rural livelihoods. Farmers in all three agro-ecosystems showed differing levels of vulnerability; susceptibility was higher, for instance, in the middle arid and southern rainfed mountainous areas, due to farmers’ greater exposure to climatic hazards and because a greater proportion of income originates from farming activities. Recent climate variability had affected many aspects of farmers’ livelihoods but it was not the only challenge they had faced. The perennially dry climate is a significant limiting factor for agricultural production in the region, greatly exacerbated by periodic reductions in moisture due to drought. Unsurprisingly, farmers have developed and continue to use a wide range of measures to retain and enhance soil moisture and to maintain agricultural production in this harsh environment: adaptation is an inherent feature of their behaviour, but their capacity to act is determined by a range of factors. When questioned on the constraints they faced respondents cited most often lack of money, water shortage and agricultural inputs. Because of the close alignment at the community and household level between adaptation and more generic individual and institutional aims for development there exists good potential to incorporate adaptation objectives and measures into mainstream development plans and poverty alleviation programmes

Decreases in global beer supply due to extreme drought and heat.

Beer is the most popular alcoholic beverage in the world by volume consumed, and yields of its main ingredient, barley, decline sharply in periods of extreme drought and heat. Although the frequency and severity of drought and heat extremes increase substantially in range of future climate scenarios by five Earth System Models, the vulnerability of beer supply to such extremes has never been assessed. We couple a process-based crop model (decision support system for agrotechnology transfer) and a global economic model (Global Trade Analysis Project model) to evaluate the effects of concurrent drought and heat extremes projected under a range of future climate scenarios. We find that these extreme events may cause substantial decreases in barley yields worldwide. Average yield losses range from 3% to 17% depending on the severity of the conditions. Decreases in the global supply of barley lead to proportionally larger decreases in barley used to make beer and ultimately result in dramatic regional decreases in beer consumption (for example, -32% in Argentina) and increases in beer prices (for example, +193% in Ireland). Although not the most concerning impact of future climate change, climate-related weather extremes may threaten the availability and economic accessibility of beer