Climate Change Scenarios A2 Research Articles

Potential impacts of climate change and climate variability on China’s rice yield and production

We assessed the effect of greenhouse gas-induced climate change, as well as the direct fertilization effect of CO2, on rice yields and production in China. Our methodology coupled the regional climate model PRECIS (Providing Regional Climates for Impacts Studies) with the CERES (Crop Environment Resources Synthesis) rice crop model to simulate current (1961-1990) and future (2011-2100) rice yields and production under A2 and B2 climate change scenarios. The movement of rice-producing areas to more favorable climatic conditions was also considered. Results demonstrate that simulated future rice yields decrease without the CO2 fertilization effect and increase in some areas and time slices with it. Yield variability measured by the coefficient of variation exhibits increases in both scenarios, with the largest increases under A2. Due to favorable climatic conditions, single rice cropping may expand further north in China, and double rice cropping may move to the northern portion of the Yangtze River basin. China's potential rice production is projected to increase in the future, due to the CO2 fertilization effect and shifts in rice-producing areas. Three rice cultiva- tion regions (Sichuan basin, Yangtze River basin, and Huang-huaihai plain) are identified as highly sensitive to future climate change if no adaptation measures are implemented, due to yield decreases and large increases in production variability.

Projecting forest tree distributions and adaptation to climate change in northern Thailand

Climate change is a global threat to biodiversity because it has the potential to cause significant impacts on the distribution of species and the composition of habitats. The objective of this research is to evaluate the consequence of climate change in distribution of forest tree species, both deciduous and evergreen species. We extracted the HadCM3 A2 climate change scenario (regionally-oriented economic development) for the year 2050 in northern Thailand. A machine learning algorithm based on maximum entropy theory (MAXENT) was employed to generate ecological niche models of forest plants. Six evergreen species and 16 deciduous species were selected using the criteria developed by the Asia Pacific Forest Genetic Resources Programme (APFORGEN) for genetic resources conservation and management. Species occurrences were obtained from the Department of National Park, Wildlife and Plant Conservation. The accuracy of each ecological niche model was assessed using the area under curve of a receiver operating characteristic (ROC) curve. The results show that the total extent of occurrence of all selected plant species is not substantially different between current and predicted climate change conditions. However, their spatial configuration and turnover rate are high, especially evergreen tree species. Ten plant species will loss their ecological niches (suitable locations) ranging from 2 - 13%, while the remaining 12 species will gain substantial suitable habitats. The assemblages of evergreen species or species richness are likely to shift toward the north where low temperature is anticipated for year 2050. In contrast, the deciduous species will expand their distribution ranges. Based on the IUCN Red List criteria, 10 plant species will be categorized as near threatened (NT) and 12 species will be listed as concerned status. An important point is that species distribution models were found to depend significantly on extreme climate variables such as minimum temperature of coldest months, and precipitation of driest and coldest quarters. Key words: Northern Thailand, climate change, forest tree species distribution model.

Future energy potential of Miscanthus in Europe

AbstractEuropean field experiments have demonstrated Miscanthus can produce some of the highest energy yields per hectare of all potential energy crops. Previous modelling studies using MISCANMOD have calculated the potential energy yield for the EU27 from mean historical climate data (1960–1990). In this paper, we have built on the previous studies by further developing a new Miscanthus crop growth model MISCANFOR in order to analyse (i) interannual variation in yields for past and future climates, (ii) genotype‐specific parameters on yield in Europe. Under recent climatic conditions (1960–1990) we show that 10% of arable land could produce 1709 PJ and mitigate 30 Tg of carbon dioxide‐carbon (CO2‐C) equivalent greenhouse gasses (GHGs) compared with EU27 primary energy consumption of 65 598 PJ, emitting 1048 Tg of CO2‐C equivalent GHGs in 2005. If we continue to use the clone Miscanthus×giganteus, MISCANFOR shows that, as climate change reduces in‐season water availability, energy production and carbon mitigation could fall 80% by 2080 for the Intergovernmental Panel on Climate Change A2 scenario. However, because Miscanthus is found in a huge range of climates in Asia, we propose that new hybrids will incorporate genes conferring superior drought and frost tolerance. Using parameters from characterized germplasm, we calculate energy production could increase from present levels by 88% (to 2360 PJ) and mitigate 42 Tg of CO2‐C equivalent using 10% arable land for the 2080 mid‐range A2 scenario. This is equivalent to 3.6% of 2005 EU27 primary energy consumption and 4.0% of total CO2 equivalent C GHG emissions.

Impacts of climate change on regional and urban air quality in the eastern United States: Role of meteorology

The effects of climate change on ozone and PM2.5 concentrations over the eastern United States were investigated using the Global‐Regional Coupled Air Pollution modeling System (GRE‐CAPS). GRE‐CAPS consists of the Goddard Institute for Space Studies (GISS) II' general circulation model with aerosol processes and ozone chemistry, the fifth‐generation PSU/NCAR mesoscale model (MM5) regional meteorological model, and the Comprehensive Air Quality Model with Extensions (CAMx) with aerosol (PM) processes developed at Carnegie Mellon University (PMCAMx) regional chemical transport model. A set of five present‐day Januaries and six present‐day Julys was simulated using GRE‐CAPS. The present‐day model predictions (2000s) were compared to model predictions for a set of five future Januaries and Julys. The future time period investigated was the 2050s, using the Intergovernmental Panel on Climate Change A2 scenario. U.S. emissions of biogenic and anthropogenic precursors were held constant so that the effects of climate change alone could be calculated. Climate change led to a decrease in U.S. land cell average January PM2.5 concentrations of 0.3 μg m−3 and an increase of July PM2.5 of 2.5 μg m−3. The changes in PM in the Northeast were of the opposite sign of the domain‐wide averages. The response in January was due largely to increased precipitation, while the response in July was due primarily to decreased ventilation, as indicated by decreases in mixing height and wind speed, with increases in sulfate being the largest response by a single species. The U.S. land cell average change in July daily maximum 8‐h ozone concentration was +1.7 ppb, though the increases in cities in the Southeast were up to 15 ppb. In spite of the large differences in ozone in many areas, the changes in ozone concentration were not statistically significant over most of the domain because of large interannual variability. In separate simulations to test the sensitivity of ozone concentrations to biogenic emissions, a 25% increase in biogenic U.S. volatile organic compound emissions led to an additional increase in land cell average ozone of 0.7 ppb, though the increased ozone resulting from increased biogenics was largely statistically insignificant.

Worldwide geographical distribution of Black Sigatoka for banana: predictions based on climate change models

As mudanças climáticas poderão alterar as doenças de plantas e afetar a eficácia das medidas de manejo. Um dos prováveis impactos será na distribuição geográfica das doenças. A Sigatoka Negra é considerada a principal doença da cultura da banana em decorrência dos danos causados e aumento do custo de manejo. O impacto sócio-econômico da doença continua aumentando, uma vez que a doença tem atingido novas áreas de plantio, tornando o manejo mais difícil. Este trabalho tem por objetivos comparar a distribuição geográfica da doença por meio da elaboração de mapas nas seguintes situações: a) clima atual e futuro (2020, 2050 e 2080), b) cenários A2 e B2 do Painel Intergovernamental de Mudanças Climáticas, c) predito por seis diferentes modelos de mudanças climáticas e pela média dos mesmos e, d) entre meses. Haverá redução das áreas favoráveis à doença no futuro, sendo que tal redução será mais acentuada no cenário A2 do que no B2 e gradativa para as décadas de 2020, 2050 e 2080. Predições efetuadas com o uso da média dos dados estimados pelos modelos permitiram redução na variabilidade da simulação em comparação com a predição gerada por cada modelo individualmente. Alterações na distribuição geográfica da doença ocorrerão entre meses, de modo que áreas consideradas desfavoráveis tornar-se-ão favoráveis e vice-versa. Apesar disso, extensas áreas continuarão favoráveis ao desenvolvimento da Sigatoka Negra.

Using maps of city analogues to display and interpret climate change scenarios and their uncertainty

Abstract. We describe a method to represent the results of climate simulation models with spatial analogues. An analogue to a city A is a city B whose climate today corresponds to A's simulated future climate. Climates were characterized and compared non-parametrically, using the 30-years distribution of three indicators: Aridity Index, Heating Degree Days and Cooling Degree Days. The level of correspondence (i.e. strength of analogy) was evaluated statistically with the two-samples Kolmogorov-Smirnov test, generalized to 3 dimensions. We looked at the climate of 12 European cities at the end of the 21st century under an A2 climate change scenario. We used two datasets produced with high-resolution regional climate simulation models from the Hadley Centre and Meteo France. As expected from the modelled warming in local climate, analogues were found in warmer regions, mostly at more southerly latitudes within Europe, although much model and scenario uncertainty remains. Climate analogues provide an intuitive way to show the possible effects of climate change on urban areas, offering a holistic approach to think about how cities might adapt to different climates. Evidence of its communication value comes from the reuse of our maps in teaching and in several European mass-media.

Frost in a future climate: modelling interactive effects of warmer temperatures and rising atmospheric [CO2] on the incidence and severity of frost damage in a temperate evergreen (Eucalyptus pauciflora)

AbstractAlthough plants are more susceptible to frost damage under elevated atmospheric [CO2], the importance of frost damage under future, warmer climate scenarios is unknown. Accordingly, we used a model to examine the incidence and severity of frost damage to snow gum (Eucalyptus pauciflora) in a sub‐alpine region of Australia for current and future conditions using the A2 IPCC elevated CO2 and climate change scenario. An existing model for predicting frost effects on E. pauciflora seedlings was adapted to include effects of elevated [CO2] on acclimation to freezing temperatures, calibrated with field data, and applied to a study region in Victoria using climate scenario data from CSIRO's Global Climate Model C‐CAM for current (1975–2004) and future (2035–2064) 30 years climate sequences. Temperatures below 0 °C were predicted to occur less frequently while the coldest temperatures (i.e. those below −8 °C) were almost as common in the future as in the current climate. Both elevated [CO2] and climate warming affected the timing and rates of acclimation and de‐acclimation of snow gum to freezing temperatures, potentially reducing the length of time that plants are fully frost tolerant and increasing the length of the growing season. Despite fewer days when temperatures fall below 0 °C in the future, with consequently fewer damaging frosts with lower average levels of impact, individual weather sequences resulting in widespread plant mortality may still occur. Furthermore, delayed acclimation due to either warming or rising [CO2] combined with an early severe frost could lead to more frost damage and higher mortality than would occur in current conditions. Effects of elevated [CO2] on frost damage were greater in autumn, while warming had more effect in spring. Thus, frost damage will continue to be a management issue for plantation and forest management in regions where frosts persist.

수자원에 대한 기후변화 영향평가를 위한 고해상도 시나리오 생산(II): 유역별 유출시나리오 구축

본 연구의 목적은 IPCC SRES A2 기후변화 시나리오를 이용하여 지역 스케일의 기후변화가 수자원에 미치는 영향을 평가할 수 있는 유출시나리오를 생산하는 것이다. 장기유출분석을 위해 PRMS 모형을 선정하였다. 유역별 PRMS 모형의 매개변수를 결정하기 위해 6개 댐유역에서 매개변수를 보정하고 지역화방법을 이용하여 미계측유역으로 전이하였다. 3개 댐유역을 미계측유역으로 가정하고 지역화방법으로 전이된 매개변수를 이용하여 모의능력을 분석하였다. 관측치와 모의치의 통계치를 분석한 결과 지역화방법을 통한 미계측유역의 유출분석은 유용한 것으로 나타났다. 생산된 시나리오의 신뢰성을 분석하기 위해 4개의 상류댐지점의 관측치와 비교하였다. 분석결과 기후시나리오 생산을 위한 기상관측소의 선정이 유역별 기후시나리오의 신뢰성에 영향을 미치는 것으로 나타났다. 유출시나리오를 이용하여 기준기간 30년(<TEX>$1971{\sim}2001$</TEX>년)과 미래 90년(<TEX>$2001{\sim}2030$</TEX>년， <TEX>$2031{\sim}2060$</TEX>년， <TEX>$2061{\sim}2090$</TEX>년)에 대해 수자원의 변동성을 분석한 결과 연평균유출량은 기준기간에 비해 대체적으로 한강유역에서는 증가하고， 나머지 유역에서는 감소하는 것으로 나타났다. The objective of this study is to generate the regional scale runoff scenarios by using IPCC SRES A2 climate change scenario for analyzing the spatial variation of water resources in Korea. The PRMS model was adopted to simulate long-term stream discharge. To estimate the PRMS model parameters on each sub-basin, the streamflow data at 6 dam sites and Rosenbrock's scheme are used for model parameter calibration and those parameters are translated to ungauged catchments by regionalization method. The other 3 dam sites are selected for the verification of the adequateness of regionalized model parameters in ungagued catchments. The statistical results show that the simulated flows by using regionalized parameters well agree with observed ones. The generated runoff scenarios by climate change are compared with observed data on 4 dam sites for the reference period. The consequences show that the selection of climate station for generating climate scenario affects the reliability of climate scenario at sub-basin. The comparison results of the stream flows between the 30-year baseline period (1971-2000) and future 90-year (2001-2030, 2031-2060, 2061-2090) show that the long-term mean annual runoff in the Han River has increasing trend, while the Nakdong, the Gum, the Youngsan and the Sumjin Rivers have decreasing trend.

Climate change and critical thresholds in China’s food security

Identification of ‘critical thresholds’ of temperature increase is an essential task for inform policy decisions on establishing greenhouse gas (GHG) emission targets. We use the A2 (medium-high GHG emission pathway) and B2 (medium-low) climate change scenarios produced by the Regional Climate Model PRECIS, the crop model – CERES, and socio-economic scenarios described by IPCC SRES, to simulate the average yield changes per hectare of three main grain crops (rice, wheat, and maize) at 50 km × 50 km scale. The threshold of food production to temperature increases was analyzed based on the relationship between yield changes and temperature rise, and then food security was discussed corresponding to each IPCC SRES scenario. The results show that without the CO2 fertilization effect in the analysis, the yield per hectare for the three crops would fall consistently as temperature rises beyond 2.5 ^C; when the CO2 fertilization effect was included in the simulation, there were no adverse impacts on China’s food production under the projected range of temperature rise (0.9–3.9 ^C). A critical threshold of temperature increase was not found for food production. When the socio-economic scenarios, agricultural technology development and international trade were incorporated in the analysis, China’s internal food production would meet a critical threshold of basic demand (300 kg/capita) while it would not under A2 (no CO2 fertilization); whereas basic food demand would be satisfied under both A2 and B2, and would even meet a higher food demand threshold required to sustain economic growth (400 kg/capita) under B2, when CO2 fertilization was considered.