North China Plain is the heartland of modern China. This fertile plain has experienced vast expansion of irrigated agriculture which cools surface temperature and moistens surface air, but boosts integrated measures of temperature and humidity, and hence enhances intensity of heatwaves. Here, we project based on an ensemble of high-resolution regional climate model simulations that climate change would add significantly to the anthropogenic effects of irrigation, increasing the risk from heatwaves in this region. Under the business-as-usual scenario of greenhouse gas emissions, North China Plain is likely to experience deadly heatwaves with wet-bulb temperature exceeding the threshold defining what Chinese farmers may tolerate while working outdoors. China is currently the largest contributor to the emissions of greenhouse gases, with potentially serious implications to its own population: continuation of the current pattern of global emissions may limit habitability in the most populous region, of the most populous country on Earth.

Abstract. Molded flexible polyurethane (PU) foams have been synthesized from polypropylene glycol (PPG) with different molecular weights (M w ) and functionalities (f), and 2,4/2,6-toluene diisocyanate (TDI-80) with water as blowing agent. It was found that the glassy state properties of the foam mainly depended on the urethane group content while the rubbery state properties on the crosslink density. That is, PPG of low MW and low f (more urethane groups) provided superior glass state modulus, strength, density, shape fixity and glass transition temperature (T g ), while that of high M w and high f (higher crosslink density) showed high rubbery modulus and shape recovery. Consequently shape fixity of low M w PPG decreased from 85 to 72% while shape recovery increased from 52 to 63% as the content of high M w PPG increased from 0 to 40%.

The crop simulation model is a suitable tool for evaluating the potential impacts of climate change on crop production and on the environment. This study investigates the effects of climate change on paddy rice production in the temperate climate regions under the East Asian monsoon system using the CERES-Rice 4.0 crop simulation model. This model was first calibrated and validated for crop production under elevated CO2 and various temperature conditions. Data were obtained from experiments performed using a temperature gradient field chamber (TGFC) with a CO2 enrichment system installed at Chonnam National University in Gwangju, Korea in 2009 and 2010. Based on the empirical calibration and validation, the model was applied to deliver a simulated forecast of paddy rice production for the region, as well as for the other Japonica rice growing regions in East Asia, projecting for years 2050 and 2100. In these climate change projection simulations in Gwangju, Korea, the yield increases (+12.6 and + 22.0%) due to CO2 elevation were adjusted according to temperature increases showing variation dependent upon the cultivars, which resulted in significant yield decreases (-22.1% and -35.0%). The projected yields were determined to increase as latitude increases due to reduced temperature effects, showing the highest increase for any of the study locations (+24%) in Harbin, China. It appears that the potential negative impact on crop production may be mediated by appropriate cultivar selection and cultivation changes such as alteration of the planting date. Results reported in this study using the CERES-Rice 4.0 model demonstrate the promising potential for its further application in simulating the impacts of climate change on rice production from a local to a regional scale under the monsoon climate system.

Background: Inconsistency in climate regimes of rainfall and temperature is a source of biotic and abiotic stresses in agricultural systems worldwide. Several studies from Bangladesh report that this variability is a cause of poor yield potential and crop failure. This study investigates the impact of temperature and rainfall variation on rice productivity for different ecosystems in Bangladesh. Three ecosystems under investigation include: dry (Rajshahi), terrace (Mymensingh) and coastal (Barisal). Results:The terrace ecosystem recorded the highest rainfall, followed by coastal and dry ecosystems. The temperature variation, both maximum and minimum, showed an increasing trend; however, the incremental rate was higher in case of minimum temperature. Monsoon rainfall showed an increasing trend, while dry season (November to March) decreased slightly. The climatic variations and impacts were captured using a standardized precipitation index (SPI), diurnal temperature range (DTR) and rice productivity index (RPI). The rainfed rice crop (aman) observed a significant trend between RPI and seasonal SPI, and between RPI and seasonal DTR. Overall, the SPI indicated the prevalence of frequent dry and wet periods and DTR recorded a decreasing trend. The multiple regression analysis identified a significant correlation between RPI, SPI and DTR accounting for 41, 45 and 49% of yield variability in dry, terrace and coastal ecosystems, respectively. Conclusion:Rainfall has shifted with an increasing trend during monsoon and almost static during other seasons. Rice production, especially rainfed rice, is at risk due to frequent drought and decreasing DTR. Stress-tolerant rice varieties requiring less irrigation water and survive at high temperature should be introduced. Research on rescheduling crop calendar and cropping pattern is necessary to mitigate the adverse climatic conditions.

This study evaluates the performance of the regional climate model RegCM4, which incorporates the Biosphere-Atmosphere Transfer Scheme (BATS) and Community Land Model (CLM3) land-surface schemes, in simulating the summer precipitation over East Asia. The characteristics of summer precipitation are analysed in terms of mean amount, frequency and intensity of daily precipitation. The results show that the simulation of the summer precipitation is significantly sensitive to the choices of the land-surface schemes. Despite several deficiencies, the simulation of daily precipitation with CLM3 exhibits superior performance to that with BATS. The BATS simulation tends to systematically overestimate both precipitation frequency and intensity, and hence total precipitation across the whole domain. On the other hand, the CLM3 simulation substantially reduces the wet biases produced in the BATS simulation. The difference in performance between the two simulations mainly results from convective precipitation rather than large-scale precipitation. Since excessive convective precipitation tends to suppress large-scale precipitation, the BATS simulation also exhibits a limitation in properly simulating the ratio of convective and large-scale precipitation. Such behaviour can be explained by the influence of soil moisture on convective precipitation. Persistently wetter soil moisture in the BATS land-surface scheme can modulate the partitioning of surface heat fluxes inadequately, leading to overestimation of latent heat flux and underestimation of sensible heat flux over South China, in particular. Consequently, it affects the thermodynamic structure (as described by the stability indices), which in turn affects the atmospheric stability to determine the convective activity. The CLM3 simulation generates a more realistic representation of equivalent potential temperature, convective available potential energy and convective inhibition, and thus improves the characteristics of daily precipitation.