Special Report On Emissions Scenarios Research Articles

Assessing the impacts of climate change and tillage practices on stream flow, crop and sediment yields from the Mississippi River Basin

This study evaluated climate change impacts on stream flow, crop and sediment yields from three different tillage systems (conventional, reduced 1–close to conservation, and reduced 2–close to no-till), in the Big Sunflower River Watershed (BSRW) in Mississippi. The Soil and Water Assessment Tool (SWAT) model was applied to the BSRW using observed stream flow and crop yields data. The model was calibrated and validated successfully using monthly stream flow data (2001–2011).The model performances showed the regression coefficient (R2) from 0.72 to 0.82 and Nash–Sutcliffe efficiency index (NSE) from 0.70 to 0.81 for streamflow; R2 from 0.40 to 0.50 and NSE from 0.72 to 0.86 for corn yields; and R2 from 0.43 to 0.59 and NSE from 0.48 to 0.57 for soybeans yields. The Long Ashton Research Station Weather Generator (LARS-WG), was used to generate future climate scenarios. The SRES (Special Report on Emissions Scenarios) A1B, A2, and B1 climate change scenarios of the Intergovernmental Panel on Climate Change (IPCC) were simulated for the mid (2046–2065) and late (2080–2099) century. Model outputs showed slight differences among tillage practices for corn and soybean yields. However, model simulated sediment yield results indicated a large difference among the tillage practices from the corn and soybean crop fields. The simulated future average maximum temperature showed as high as 4.8°C increase in the BSRW. Monthly precipitation patterns will remain un-changed based on simulated future climate scenarios except for an increase in the frequency of extreme rainfall events occurring in the watershed. On average, the effect of climate change and tillage practice together did not show notable changes to the future crop yields. The reduced tillage 2 practices showed the highest responses of erosion control to climate change followed by the reduced tillage 1 and conventional tillage in this study.

Evaluation of Future East Asia Drought Using Multi-Model Ensemble

We analyzed the changes in precipitation and drought climatology over East Asia by global warming using the daily precipitation data from 14 coupled atmosphere-ocean general circulation model simulations under the Special Report on Emission Scenarios (SRES) A1B scenario at the end of the twenty-first century. The models were consistent in predicting an increase in the mean precipitation over East Asia. However, the increase was less significant in Southeast Asia, and was accompanied by even larger increase in precipitation variability. This predicted precipitation climatology was translated into a change in drought climatology using the effective drought index (EDI). According to the increased precipitation, East Asia tends to be wetter with a decreased frequency and duration of drought. However, because of the enhanced precipitation variability, extreme droughts are predicted to be more frequent, especially over Southeast Asia.

Climate change in Algeria and its impact on durum wheat

According to IPCC reports, the Mediterranean basin and particularly the North African area are amongst the most vulnerable regions to climate change. However, the information concerning the North African zone is very limited, and studies on climate change have never been conducted in Algeria up to now. This paper aims at bridging this information gap and initiates a first research on the impact of climate change on durum wheat cropping, the most strategic commodity in the food system and in the national economy of Algeria. Climate projections for the distant future (2071–2100), obtained from the ARPEGE-Climate model of Meteo-France run under the medium A1B SRES scenario, are introduced into a simple agrometeorological crop model previously validated with field data. Two options for the sowing date are assessed: a dynamical date, chosen within the traditional sowing window by means of a rainfall criterion, or a prescribed date with supplemental irrigation on the same day. Crop development is modelled using thermal time, and maximum yield is determined from the accumulation of solar radiation. A water stress index is inferred from a daily water balance model, and actual yield is estimated from potential yield corrected by the water stress index. The model also takes into account the occurrence of dry periods during the growing season, which can induce partial or total failure of the crop cycle. Two stations, representative of two of the three agroclimatic areas where durum wheat is grown, were chosen: Algiers in the central northern region and Bordj Bou Arreridj in the eastern high plains. Climate change is not similar for both areas, but a tendency towards aridity is clear especially in spring. Future temperature and potential evapotranspiration increase in both regions with a maximum in spring and summer. In Algiers, rainfall will decrease throughout the year and mainly in spring and summer. Conversely, summer precipitation in Bordj Bou Arreridj will increase significantly. In both regions, the autumn rains will increase in the future climate, the possibilities of early sowing will be improved, crop cycle will be reduced, and harvest will take place earlier. In Algiers, yields tend to decrease in the future climate, whereas in Bordj Bou Arreridj, a dynamical (earlier) sowing will tend to keep yields at their current level.

Simulating future wheat yield under climate change, carbon dioxide enrichment and technology improvement in Iran. Case study: Azarbaijan region

Climate change and technology development can affect crop productivity in future conditions. Precise estimation of crops yield change as affected by climate and technology in the future is an effective approach for management strategies. The aim of this study was to estimate the impacts of climate change, technology improvement, CO2 enrichment, and overall impacts on wheat yield under future conditions. Wheat yield was projected for three future time periods (2020, 2050 and 2080) compared to baseline year (2011) under two scenarios of IPCC Special Report on Emission Scenarios (SRES) including SRES-A2 as regional economic scenario and SRES-B1 as global environmental scenario in Azarbaijan region (NW of Iran). A linear regression model, describing the relationship between wheat yield and historical year, was developed to investigate technology development effect. The decision support system for agro-technology transfer (DSSAT4.5) was used to evaluate the influence of climate change on wheat yield. The most positive effects were found for wheat yield as affected by technology in all studied regions. Under future climate change, the SRES projected a decrease in yield, especially in West Azarbaijan region. When the effects of elevated CO2 were considered, all regions resulted to increase in wheat yield. Considering all components effect in comparison with baseline (2011), yield increase would range from 5% to 38% across all times, scenarios and regions. According to our findings, it seems that we may expect a higher yield of wheat in NW Iran in the future if technology development continues as well as past years.

Changes in Tropical Cyclone Activity over Northwest Western Australia in the Past 50 Years and a View of the Future 50 Years

Abstract In the first half of this research, this study examines the trend in tropical cyclone (TC) activity over the economically important northwest Western Australia (NWA) TC basin (equator–40°S, 80°–140°E) based on statistical analyses of the International Best Track Archive for Climate Stewardship (IBTrACS) and large-scale environmental variables, which are known to be closely linked to the formation and longevity of TCs, from NCEP–NCAR reanalyses. In the second half, changes in TC activity from climate model projections for 2000–60 are compared for (i) no scenario change (CNTRL) and (ii) the moderate IPCC Special Report on Emission Scenarios (SRES) A1B scenario (EGHG). The aims are to (i) determine differences in mean annual TC frequency and intensity trends, (ii) test for differences between genesis and decay positions of CNTRL and EGHG projections using a nonparametric permutation test, and (iii) use kernel density estimation (KDE) for a cluster analysis of CNTRL and EGHG genesis and decay positions and generate their probability distribution functions. The main findings are there is little difference in the mean TC number over the period, but there is a difference in mean intensity; CNTRL and EGHG projections differ in mean genesis and decay positions in both latitude and longitude; and the KDE reveals just one cluster in both CNTRL and EGHG mean genesis and decay positions. The EGHG KDE is possibly disjoint, with a wider longitudinal spread. The results can be explained in terms of physical, meteorological, and sea surface temperature (SST) conditions, which provide natural limits to the spread of the genesis and decay points.

Climate change and its impacts on river discharge in two climate regions in China

Abstract. Understanding the heterogeneity of climate change and its impacts on annual and seasonal discharge and the difference between median flow and extreme flow in different climate regions is of utmost importance to successful water management. To quantify the spatial and temporal heterogeneity of climate change impacts on hydrological processes, this study simulated river discharge in the River Huangfuchuan in semi-arid northern China and in the River Xiangxi in humid southern China. The study assessed the uncertainty in projected discharge for three time periods (2020s, 2050s and 2080s) using seven equally weighted GCMs (global climate models) for the SRES (Special Reports on Emissions Scenarios) A1B scenario. Climate projections that were applied to semi-distributed hydrological models (Soil Water Assessment Tools, SWAT) in both catchments showed trends toward warmer and wetter conditions, particularly for the River Huangfuchuan. Results based on seven GCMs' projections indicated changes from −1.1 to 8.6 °C and 0.3 to 7.0 °C in seasonal temperature and changes from −29 to 139 % and −32 to 85 % in seasonal precipitation in the rivers Huangfuchuan and Xiangxi, respectively. The largest increases in temperature and precipitation in both catchments were projected in the spring and winter seasons. The main projected hydrologic impact was a more pronounced increase in annual discharge in the River Huangfuchuan than in the River Xiangxi. Most of the GCMs projected increased discharge in all seasons, especially in spring, although the magnitude of these increases varied between GCMs. The peak flows were projected to appear earlier than usual in the River Huangfuchuan and later than usual in the River Xiangxi, while the GCMs were fairly consistent in projecting increased extreme flows in both catchments with varying magnitude compared to median flows. For the River Huangfuchuan in the 2080s, median flow changed from −2 to 304 %, compared to a −1 to 145 % change in high flow (Q05 exceedance threshold). For the River Xiangxi, low flow (Q95 exceedance threshold) changed from −1 to 77 % and high flow changed from −1 to 62 %, while median flow changed from −4 to 23 %. The uncertainty analysis provided an improved understanding of future hydrologic behavior in the watershed. Furthermore, this study indicated that the uncertainty constrained by GCMs was critical and should always be considered in analysis of climate change impacts and adaptation.

Sustainable grassland systems: a modelling perspective based on the North Wyke Farm Platform.

SummaryThe North Wyke Farm Platform (NWFP) provides data from the field‐ to the farm‐scale, enabling the research community to address key issues in sustainable agriculture better and to test models that are capable of simulating soil, plant and animal processes involved in the systems. The tested models can then be used to simulate how agro‐ecosystems will respond to changes in the environment and management. In this study, we used baseline datasets generated from the NWFP to validate the Soil‐Plant‐Atmosphere Continuum System (SPACSYS) model in relation to the dynamics of soil water content, water loss from runoff and forage biomass removal. The validated model, together with future climate scenarios for the 2020s, 2050s and 2080s (from the International Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES): medium (A1B) and large (A1F1) emission scenarios), were used to simulate the long‐term responses of the system with three contrasting treatments on the NWFP. Simulation results demonstrated that the SPACSYS model could estimate reliably the dynamics of soil water content, water loss from runoff and drainage, and cut biomass for a permanent sward. The treatments responded in different ways under the climate change scenarios. More carbon (C) is fixed and respired by the swards treated with an increased use of legumes, whereas less C was lost through soil respiration with the planned reseeding. The deep‐rooting grass in the reseeding treatment reduced N losses through leaching, runoff and gaseous emissions, and water loss from runoff compared with the other two treatments.

Climate change impacts on the sustainability of the firewood harvest and vegetation and soil carbon stocks in a tropical dry forest in Santa Teresinha Municipality, Northeast Brazil

The Brazilian semi-arid region is characterized by low and erratic rainfall, high temperatures and high potential evapotranspiration. The removal of firewood from the native tropical dry forest, called “Caatinga”, can negatively impact important ecosystem services, such as soil conservation, water resources, biodiversity and atmospheric carbon capture, if performed in an unsustainable manner. Most global climate models indicate that Caatinga will experience temperature increases and rainfall decreases in the next few decades. We used the Century model to simulate the impact of climate changes on woody vegetation growth and on vegetation and soil organic carbon stocks in a Caatinga area managed with a single clear cut or cuts every 10years, 15years, and 20years, followed or not followed by the burning of plant residues (leaves and small branches) left after firewood removal. The effects of future climate projections, (LOW, MIDI and HIGH members of the climate scenario SRES A1B, which corresponded to different CO2 emission predictions, downscaled by the Eta/CPTEC model), were compared to those of the projection of the historical climate. With the current climate, it would take 50years to regenerate the Caatinga biomass stock to a level close to that before cutting after a single cut, followed or not followed by fire. Therefore, the recommended cutting cycles (10–20years) were not long enough to allow for the regeneration of a fully mature Caatinga. However, all of these cycles reached sustainable biomass production levels, with similar total productions until the end of the century. Under these conditions, the lower proportions of biomass recovery of shorter cycles would be compensated by more frequent cutting. The model also indicated that burning or not burning the residues would have little effect. On the contrary, if the climate changes as predicted, the biomass of the native Caatinga vegetation and soil organic carbon stock would decrease throughout this century, even without cutting the vegetation. All of the cutting cycles would not provide sustainable firewood production, with reduced production after each consecutive cut. Therefore, if the climate changes as expected, forest management legislation should require longer periods of forest recovery between cutting cycles for sites with environmental conditions (e.g., climate, soil and vegetation) similar to those of the present study.

Global Food Demand Scenarios for the 21st Century.

Long-term food demand scenarios are an important tool for studying global food security and for analysing the environmental impacts of agriculture. We provide a simple and transparent method to create scenarios for future plant-based and animal-based calorie demand, using time-dependent regression models between calorie demand and income. The scenarios can be customized to a specific storyline by using different input data for gross domestic product (GDP) and population projections and by assuming different functional forms of the regressions. Our results confirm that total calorie demand increases with income, but we also found a non-income related positive time-trend. The share of animal-based calories is estimated to rise strongly with income for low-income groups. For high income groups, two ambiguous relations between income and the share of animal-based products are consistent with historical data: First, a positive relation with a strong negative time-trend and second a negative relation with a slight negative time-trend. The fits of our regressions are highly significant and our results compare well to other food demand estimates. The method is exemplarily used to construct four food demand scenarios until the year 2100 based on the storylines of the IPCC Special Report on Emissions Scenarios (SRES). We find in all scenarios a strong increase of global food demand until 2050 with an increasing share of animal-based products, especially in developing countries.

青藏高原21世纪气候和环境变化预估研究进展

Research into projected climate and environmental changes across the Tibetan Plateau in the 21st century is reviewed. Climate and environmental factors involved include surface air temperature, rainfall, extreme weather and climate events, frozen soil, snow cover, glaciers, runoff, and vegetation. Projections are mainly from climate model simulations under the Special Report on Emissions Scenarios (SRES) and Representative Concentration Pathway (RCP) as well as from physical statistical models. In the future, surface air temperature across the Tibetan Plateau will rise and this rise will become more rapid in the late 21st century. Generally, in that century, rainfall, extreme weather and climate events, and active layer depth of frozen soil across the plateau will increase. However, near-surface permafrost area, snow-covered days, snow water equivalent, and glacier coverage and amount will decrease. Changes of runoff across the plateau show complexity during the 21st century. Runoff varies greatly by drainage basin, with some basins showing increases and others decreases. Vegetation is sensitive and fragile in response to the climate change. In the middle and late century, growing season will lengthen, evergreen forest/woodland will replace alpine tundra on the southern and eastern plateau, and scrub vegetation will expand and invade the alpine steppe region. Based on existing research, we comprehensively integrate all these projected climate and environmental factors and present their potential changing ranges in the middle (2030-2050) and late (2080-2100) portions of the 21st century.

Historical and potential changes of precipitation and temperature of Alberta subjected to climate change impact: 1900–2100

We investigated changes to precipitation and temperature of Alberta for historical and future periods. First, the Mann-Kendall test and Sen’s slope were used to test for historical trends and trend magnitudes from the climate data of Alberta, respectively. Second, the Special Report on Emissions Scenarios (SRES) (A1B, A2, and B1) of CMIP3 (Phase 3 of Coupled Model Intercomparison Project), projected by seven general circulation models (GCM) of the Intergovernmental Panel on Climate Change (IPCC) for three 30 years periods (2020s, 2050s, and 2080s), were used to evaluate the potential impact of climate change on precipitation and temperature of Alberta. Third, trends of projected precipitation and temperature were investigated, and differences between historical versus projected trends were estimated. Using the 50-km resolution dataset from CANGRD (Canadian Grid Climate Data), we found that Alberta had become warmer and somewhat drier for the past 112 years (1900–2011), especially in central and southern Alberta. For observed precipitation, upward trends mainly occurred in northern Alberta and at the leeward side of Canadian Rocky Mountains. However, only about 13 to 22 % of observed precipitation showed statistically significant increasing trends at 5 % significant level. Most observed temperature showed significant increasing trends, up to 0.05 °C/year in DJF (December, January, and February) in northern Alberta. GCMs’ SRES projections indicated that seasonal precipitation of Alberta could change from −25 to 36 %, while the temperature would increase from 2020s to 2080s, with the largest increase (6.8 °C) in DJF. In all 21 GCM-SRES cases considered, precipitation in both DJF and MAM (March, April, and May) is projected to increase, while temperature is consistently projected to increase in all seasons, which generally agree with the trends of historical precipitation and temperature. The SRES A1B scenario of CCSM3 might project more realistic future climate for Alberta, where its water resources can become more critical in the future as its streamflow is projected to decrease continually in the future.

Vulnerability of Water Demand and Aquatic Habitat in the Context of Climate Change and Analysis of a No-Regrets Adaptation Strategy: Study of the Yamaska River Basin, Canada

AbstractClimate change will have a significant impact on the hydrological cycle. This paper presents the results of a pilot project for the Yamaska River in Quebec. The objective of this project is to evaluate the river’s vulnerability to low flows attributable to climate change and to analyze a no-regrets adaptation strategy at locations identified as vulnerable. The vulnerability was evaluated using statistical indicators (low flow indices) based on long-term observations at four locations in the basin. A distributed physically-based hydrological model in use in Quebec was calibrated and validated against observed streamflow data to properly represent low flows. Hydrological simulations used seven climate projections provided by the north american regional climate change assessment program (NARCCAP) s project. Also, five members of the canadian regional climate model (CRCM), nested with the coupled global climate model (CGCM) under the special report on emission scenarios (SRES) A2 emission scenario, we...

Development of human health damage factors related to CO2 emissions by considering future socioeconomic scenarios

Global warming is exerting a damaging effect on human health. This damage is not only influenced by future climate conditions but also projected economic development and population growth. That being said, there are no health damage factors related to CO2 emissions which take into account future socioeconomic scenarios in life cycle impact assessment (LCIA). Thus, the purpose of the current research is to calculate human health damage factors based on the Special Report on Emission Scenarios (SRESs) developed by the Intergovernmental Panel on Climate Change (IPCC). The procedure used to calculate the SRES-based damage factors is as follows. First, a framework was developed to calculate damage factors based on multiple parameters: rise in temperature, relative risk increase, mortality rate increase, rise in number of deaths, and disability-adjusted life year (DALY) increase. Secondly, these parameters were calculated for each individual SRES based on the relationship among the parameters and CO2 emissions, GDP, and population values of each scenario. Finally, the damage factor for each SRES was calculated by multiplying all the parameters that had been calculated based on the CO2 emission, GDP, and population data in the corresponding scenarios. Using this method, the human health damage factors for four SRESs (A1B, A2, B1, and B2) were calculated. The damage factors consisted of six different items: malaria, diarrhea, cardiovascular disease, malnutrition, coastal flooding, and inland flooding. The calculated results by scenario were 2.0 × 10−7, 6.2 × 10−7, 2.1 × 10−7, and 4.2 × 10−7 DALY/kg CO2, respectively. The damage caused by malnutrition is the greatest, followed by diarrhea. Regions of Southeast Asia, Africa, and the Middle East showed the highest damages due to their high damage from malnutrition and diarrhea. With regard to the differences among the four damage factors, the difference between the projected future mortality rate and DALY per death based on the future GDP per capita is greater than the difference between the increases in temperature among scenarios dependent on future CO2 emission. The human health damage factors related to CO2 emissions for four SRESs were estimated. As a result of differences between future socioeconomic scenarios, the largest amount of damage per CO2 emission unit was three times greater than the smallest amount. Therefore, sensitive analysis is highly recommended when seeking to compare damage caused by global warming and other impact categories.

Pastoral suitability driven by future climate change along the Apennines

This work aims at evaluating the impacts of climate change on pastoral resources located along the Apennines chain. To this end, random forest machine learning model was first calibrated for the present period and then applied to future conditions, as projected by HadCM3 general circulation model, in order to simulate possible spatial variation/shift of pastoral areas in two time slices (centred on 2050 and 2080) under A2 and B2 SRES scenarios. Pre-existent spatial database, namely Corine land cover map and WorldClim, were integrated and harmonised in a GIS environment in order to extract climate variables (mean seasonal precipitation, mean maximum temperature of the warmest month and minimum temperature of the coldest month) and response variables (presence/absence of pastures) to be used as model predictors. Random forest model resulted robust and coherent to simulate pastureland suitability under current climatology (classification accuracy error=19%). Accordingly, results indicated that increases in temperatures coupled with decreases in precipitation, as simulated by HadCM3 in the future, would have impacts of great concern on potential pasture distribution. In the specific, an overall decline of pasturelands suitability is predicted by the middle of the century in both A2 (–46%) and B2 (–41%) along the entire chain. However, despite alarming reductions in pastures suitability along the northern (–69% and –71% under A2 and B2 scenarios, respectively) and central Apennines (–90% under both scenarios) by the end of the century, expansions are predicted along the southern areas of the chain (+96% and +105% under A2 and B2 scenarios, respectively). This may be probably due to expansions in pastures dominated by xeric and thermophiles species, which will likely benefit from warmer and drier future conditions predicted in the southern zone of the chain by the HadCM3. Hence, the expected climate, coupled with an increasing abandonment of the traditional grazing practices, will likely threat grassland biodiversity as well as pastoral potential distribution currently dominating the Apennines chain.

Characterization of the wind speed variability and future change in the Iberian Peninsula and the Balearic Islands

AbstractWind energy is susceptible to global climate change because it could alter the wind patterns. Then, improvement of our knowledge of wind field variability is crucial to optimize the use of wind resources in a given region.Here, we quantify the effects of climate change on the surface wind speed field over the Iberian Peninsula and Balearic Islands using an ensemble of four regional climate models driven by a global climate model.Regions of the Iberian Peninsula with coherent temporal variability in wind speed in each of the models are identified and analysed using cluster analysis. These regions are continuous in each model and exhibit a high degree of overlap across the models. The models forced by the European Reanalysis Interim (ERA‐Interim) reanalysis are validated against the European Climate Assessment and Dataset wind. We find that regional models are able to simulate with reasonable skill the spatial distribution of wind speed at 10 m in the Iberian Peninsula, identifying areas with common wind variability.Under the Special Report on Emissions Scenarios (SRES) A1B climate change scenario, the wind speed in the identified regions for 2031–2050 is up to 5% less than during the 1980–1999 control period for all models. The models also agree on the time evolution of spatially averaged wind speed in each region, showing a negative trend for all of them. These tendencies depend on the region and are significant at p = 5% or slightly more for annual trends, while seasonal trends are not significant in most of the regions and seasons. Copyright © 2015 John Wiley & Sons, Ltd.

Estimating the effects of potential climate and land use changes on hydrologic processes of a large agriculture dominated watershed

Land use and climate are two major components that directly influence catchment hydrologic processes, and therefore better understanding of their effects is crucial for future land use planning and water resources management. We applied Soil and Water Assessment Tool (SWAT) to assess the effects of potential land use change and climate variability on hydrologic processes of large agriculture dominated Big Sioux River (BSR) watershed located in North Central region of USA. Future climate change scenarios were simulated using average output of temperature and precipitation data derived from Special Report on Emission Scenarios (SRES) (B1, A1B, and A2) for end-21st century. Land use change was modeled spatially based on historic long-term pattern of agricultural transformation in the basin, and included the expansion of corn (Zea mays L.) cultivation by 2, 5, and 10%. We estimated higher surface runoff in all land use scenarios with maximum increase of 4% while expanding 10% corn cultivation in the basin. Annual stream discharge was estimated higher with maximum increase of 72% in SRES-B1 attributed from higher groundwater contribution of 152% in the same scenario. We assessed increased precipitation during spring season but the summer precipitation decreased substantially in all climate change scenarios. Similar to decreased summer precipitation, discharge of the BSR also decreased potentially affecting agricultural production due to reduced future water availability during crop growing season in the basin. However, combined effects of potential land use change with climate variability enhanced for higher annual discharge of the BSR. Therefore, these estimations can be crucial for implications of future land use planning and water resources management of the basin.

The implication of irrigation in climate change impact assessment: a European-wide study.

This study evaluates the impacts of projected climate change on irrigation requirements and yields of six crops (winter wheat, winter barley, rapeseed, grain maize, potato, and sugar beet) in Europe. Furthermore, the uncertainty deriving from consideration of irrigation, CO2 effects on crop growth and transpiration, and different climate change scenarios in climate change impact assessments is quantified. Net irrigation requirement (NIR) and yields of the six crops were simulated for a baseline (1982-2006) and three SRES scenarios (B1, B2 and A1B, 2040-2064) under rainfed and irrigated conditions, using a process-based crop model, SIMPLACE <LINTUL5, DRUNIR, HEAT>. We found that projected climate change decreased NIR of the three winter crops in northern Europe (up to 81mm), but increased NIR of all the six crops in the Mediterranean regions (up to 182mmyr(-1) ). Climate change increased yields of the three winter crops and sugar beet in middle and northern regions (up to 36%), but decreased their yields in Mediterranean countries (up to 81%). Consideration of CO2 effects can alter the direction of change in NIR for irrigated crops in the south and of yields for C3 crops in central and northern Europe. Constraining the model to rainfed conditions for spring crops led to a negative bias in simulating climate change impacts on yields (up to 44%), which was proportional to the irrigation ratio of the simulation unit. Impacts on NIR and yields were generally consistent across the three SRES scenarios for the majority of regions in Europe. We conclude that due to the magnitude of irrigation and CO2 effects, they should both be considered in the simulation of climate change impacts on crop production and water availability, particularly for crops and regions with a high proportion of irrigated crop area.

Current and future estimates for the fire frequency and the fire rotation period in the main woodland types of peninsular Spain: a case-study approach

Aim of study. Fire regimes are frequently dynamic and change as a function of the interactions between the three main fire drivers: fuels, ignitions and climatic conditions. We characterized the recent period (1974-2005) and performed estimates for the future fire regimeArea of study. We have considered five pine and another four woodland types by means of the analyses of 100 reference areas in peninsular Spain.Material and methods. The estimates of the expected alterations in fire frequency and the fire rotation period were based on models previously developed for the climatic scenarios SRES A2 and B2.Main results. The results point to the large variability in fire frequency and rotation periods between the woodland types as defined, and also among the reference areas delimited for each of them. Fire frequencies will increase for all woodland types while very relevant shortenings of the fire rotation periods are expected. For the 32 yr period analysed, rotation periods longer than 500 yr were obtained in 54% of the reference areas while this percentage would decrease to 31% in the B2 and to 29% in the A2 climatic scenario. In the most affected woodland type, P. pinaster, from a median rotation period of 83 yr it would decrease to 26 yr in the B2 and to 20 yr in the A2 climatic scenario.Research highlights. We conclude that the predicted increases in fire activity will have adverse effects on some of the main Spanish woodland types due to the expected future disruptions in the fire regime. Keywords: Forest fires; fire regime; fire frequency; fire rotation period; climatic change.Abbreviations used: SRES: Special Report on Emissions Scenarios; IPCC: Intergovernmental Panel on Climate Change; RA: Reference Areas.

A high‐resolution, multi‐model analysis of Irish temperatures for the mid‐21st century

ABSTRACTThere is a paucity of dynamically downscaled climate model output at a high resolution over Ireland, of temperature projections for the mid‐21st century. This study aims to address this shortcoming. A preliminary investigation of global climate model (GCM) data and high‐resolution regional climate model (RCM) data shows that the latter exhibits greater variability over Ireland by reducing the dominance of the surrounding seas on the climate signal. This motivates the subsequent dynamical downscaling and analysis of the temperature output from three high‐resolution (4–7 km grid size) RCMs over Ireland. The three RCMs, driven by four GCMs from CMIP3 and CMIP5, were run under different Special Report on Emissions Scenarios (SRES) and representative concentration pathway (RCP) future scenarios. Projections of mean and extreme temperature changes are considered for the mid‐century (2041–2060) and assessed relative to the control period of 1981–2000.Analysis of the RCM data shows that annual mean temperatures are projected to rise between 0.4 and 1.8 °C above control levels by mid‐century. On a seasonal basis, results differ by forcing scenario. Future summers have the largest projected warming under RCP 8.5, where the greatest warming is seen in the southeast of Ireland. The remaining two high emission scenarios (SRESs A1B and A2) project future winters to have the greatest warming, with almost uniform increases of 1.5–2 °C across the island.Changes in the bidecadal 5th and 95th percentile values of daily minimum and maximum temperatures, respectively, are also analysed. The greatest change in daily minimum temperature is projected for future winters (indicating fewer cold nights and frost days), a pattern that is consistent across all scenarios/forcings.An investigation into the distribution of temperature under RCP 8.5 shows a strong summer increase compounded by increased variability, and a winter increase compounded by an increase in skewness.

Study of the Climate Change Impacts on Water Quality in the Upstream Portion of the Cau River Basin, Vietnam

This paper presents simulations of climate change impacts on water quality in the upstream portion of the Cau River Basin in the North of Vietnam. The integrated modeling system GIBSI was used to simulate hydrological processes, pollutant and sediment wash-off in the river basin, and pollutant transport and transformation in the river network. Three projections for climate change based on emission scenarios B1, B2, and A2 of IPCC Special Report on Emission Scenarios (SRES) were considered. By assuming that the input pollution sources and watershed configuration were constant, based on 2008 data, water quality in the river network was simulated up to the terminal year 2050. For each climate change scenario, patterns of precipitation in wet and dry year were considered. The change in annual and monthly trends for dissolved oxygen (DO), biochemical oxygen demand (BOD), and ammonium ions (NH4+) load and concentration for different portions of the watershed have been analyzed. The results of these simulations show that climate change has more impact on changing the seasonal water quality parameters than on altering the average annual load of the pollutants. The percent change and change pattern in water quality parameters are different for wet and dry year, and the changes in wet year are smaller than those in dry year.