Greenhouse Gas Scenarios Research Articles

The ongoing range expansion of the invasive oak lace bug across Europe: current occurrence and potential distribution under climate change

In recent years, the oak lace bug, Corythucha arcuata, has emerged as a significant threat to European oak forests. This species, native to North America, has in the last two decades rapidly extended its range in Europe, raising concerns about its potential impact on the continent's invaluable oak populations. To address this growing concern, we conducted an extensive study to assess the distribution, colonization patterns, and potential ecological niche of the oak lace bug in Europe.We gathered 1792 unique presence coordinates from 21 Eurasian countries, utilizing diverse sources such as research observations, citizen science initiatives, GBIF database, and social media reports. To delineate the realized niche and future distribution, we employed an ensemble species distribution modelling (SDM) framework. Two future greenhouse gas scenarios (RCP 4.5 and RCP 8.5) were considered across three-time intervals (2021–2040, 2061–2080, and 2081–2100) to project and evaluate the species' potential distribution in the future.Our analysis revealed that significant hotspots rich in host species occurrence for this invasive insect remain uninvaded so far, even within its suitable habitat. Furthermore, the native ranges of Turkey oak (Quercus cerris L.) and Hungarian oak (Quercus frainetto L.) species offer entirely suitable environments for the oak lace bug. In contrast, the pedunculate oak and sessile oak distribution ranges currently show only 40 % and 50 % suitability for colonization, respectively. However, our predictive models indicate a significant transformation in the habitat suitability of the oak lace bug, with suitability for these two oak species increasing by up to 90 %. This shift underlines an evolving landscape where the oak lace bug may exploit more of its available habitats than initially expected. It emphasises the pressing need for proactive measures to manage and stop its expanding presence, which may lead to a harmful impact on the oak population across the European landscape.

Projected Thermally Driven Elderly Mortality for Beijing Under Greenhouse Gas and Stratospheric Aerosol Geoengineering Scenarios

AbstractBeijing is undergoing multiple challenges including urbanization, warming and aging. The Beijing megalopolis of 20 million people now suffers more cold‐related than heat‐related deaths. Stratospheric aerosol injection (SAI) geoengineering is designed to lower surface temperatures, so if SAI were ever done, it may reduce future heat‐related mortality, while also increasing cold‐related mortality. Here we use four Earth System Models (ESM) downscaled to 10 km resolution with the Weather Research and Forecasting (WRF) system to capture urban temperature, humidity and wind speeds. Temperature‐related mortality risk were calculated using a distributed lag nonlinear model (DLNM) of the elderly (over 65s) under the dynamically downscaled moderate (RCP4.5) and extreme (RCP8.5) greenhouse gas, and the G4 SAI scenarios. We used population demographics for all five shared socioeconomic pathways (SSP) and various adaptation measures. Heat‐related excess deaths under G4 are 630∼3,160 per year fewer than RCP4.5, while cold‐related deaths are 370∼1,990 more than RCP4.5 during 2060–2069, with a marginally significant net reduction. G4 significantly reduces the excess deaths relative to RCP8.5. Both heat‐related and cold‐related mortality will increase by 240∼490% when the aging population is accounted for, and decrease by 11%, 23% and 44% under low, medium and high adaptation relative to a no adaptation scenario. Dynamical downscaling produces better quality climate simulations than commonly used statistical approaches, and in the case of Beijing, significantly fewer heat‐related deaths. The marginal health benefits of modest future SAI in Beijing may be representative of the population impacts in the extra‐tropics where deaths due to cold are more than those caused by heat.

North–South Disparity in Impact of Climate Change on “Outdoor Days”

Abstract Here, we introduce the concept of “outdoor days” to describe how climate change can affect quality of life for different communities and individuals. An outdoor day is characterized by moderate temperature, neither too cold nor too hot, allowing most people to enjoy outdoor activities. The number of “outdoor days” is a nonlinear function of the daily surface air temperature. If the latter falls within a specific range describing assumed thermal comfort conditions, then we assign that day as an “outdoor day.” Using this function, we describe climate change impacts on temperature differently, compared to other studies which often describe these impacts in terms of the linear averaging of daily surface air temperature. The introduction of this new concept offers another way for communicating how climate change may impact the quality of life for individuals who usually plan their outdoor activities based on how local weather conditions compare to their preferred levels of thermal comfort. Based on our analysis of regional variations in “outdoor days,” we present observational and modeling evidence of a north–south disparity in climate change impacts. Under high-emission scenarios, CMIP5 and CMIP6 models project fewer “outdoor days” for people living in developing countries, primarily located in low-latitude regions. Meanwhile, developed countries in mid- and high-latitude regions could gain more “outdoor days,” redistributed across seasons. Significance Statement We introduce a novel concept: outdoor days, characterizing surface air temperature conditions that allow for outdoor activities, such as walking, jogging, and cycling, by most people. We project that under high-emission scenarios of anthropogenic greenhouse gases, a north–south disparity of climate change risk will be enhanced considerably toward the end of this century due to more frequent outdoor days in the wealthy Global North and less frequent outdoor days in the deprived Global South.

Multi‐Model Simulation of Solar Geoengineering Indicates Avoidable Destabilization of the West Antarctic Ice Sheet

AbstractHeat transported in Circumpolar Deep Water is driving the break‐up of ice shelves in the Amundsen Sea sector of Antarctica, that has been simulated to be unavoidable under all plausible greenhouse gas scenarios. However, Solar geoengineering scenarios remain largely unexplored. Solar geoengineering changes global thermal radiative balance, and atmospheric and oceanic transportation pathways. We simulate stratospheric aerosol injection (SAI) designed to reduce global mean temperatures from those under the unmitigated SSP5‐8.5 scenario to those under the SSP2‐4.5 scenario with six CMIP6‐class Earth System Models. These consistently show intensified Antarctic polar vortex and sub‐polar westerlies, which mitigates changes to easterly winds along the Amundsen Sea continental shelf compared with greenhouse gas scenarios. The models show significantly cooler Amundsen Sea waters and lower heat content at 300–600 m under SAI than with either solar dimming or the SSP5‐8.5 unmitigated greenhouse gas scenarios. However, the heat content increases under all scenarios compared with present day suggesting that although vulnerable ice shelves would continue to thin, the rate would be lower for SAI even with SSP5‐8.5 specified greenhouse gases, than for the moderate (SSP2‐4.5) scenario. The simulations here use solar geoengineering designed to meet global temperature targets; interventions targeted at preserving the frozen high latitudes have also been proposed that might be expected to produce bigger local effects, but potentially deleterious impacts elsewhere. Considering the huge disruptions to society of ice sheet collapse, more research on avoiding them by intervention technology is a moral imperative.

Prediction of ambulance transport system collapse under extremely high temperatures induced by climate change

The heat-related health impacts of extremely high temperatures have become increasingly severe worldwide. Quantitative information on these impacts is necessary to plan and implement adaptation measures. The present study aimed to predict the number of heatstroke ambulance calls (HAC) and ambulance occupancy rate of patients with heatstroke (AORPH) under extremely high temperatures in Tokyo, Japan. Extremely high temperatures were defined as the annual highest value of daily maximum temperature that occurs once every 30 y (30 y temp) or 50 y (50 y temp). Combinations of three greenhouse gas (GHG) emission scenarios and five climate models were adopted to predict the impacts during the base years (1985–2014), mid-21st century (2021–2050), and late 21st century (2071–2100). Furthermore, two types of populations were adopted: fixed and changing. In the case of 50 y temp, the HAC during the peak hour in the base years ranged from 52 to 130 persons across the climate models. In the case of a fixed population, in the late 21st century it ranged from 123 to 2618 persons across the climate models and GHG scenarios. In the case of a changing population, the corresponding values in late 21st century ranged from 128 to 3078 persons. The AORPH during the peak hour ranged from 32% to 80% during the base years for 50 y temp, assuming that all ambulances were dispatched for heatstroke only. In the late 21st century, it ranged from 75% to 1605% in the fixed population case. With population change, the corresponding values in late 21st century ranged from 83% to 1781%. In many scenarios, not all patients with heatstroke could be transported (AORPH > 100%) even if all ambulances have been dispatched. Therefore, adaptation measures that mitigate such an ambulance transport system collapse must be planned and implemented.

Are our lands getting wetter or drier? A perspective from Climate scenario data in Upper Brantas

Changes in rainfall are considered influential for sustaining the land resources in tropical agriculture. Many areas in East Java are classified as top priorities in adaptation and mitigation programs, especially in the agricultural and water resources sectors. Climate change impacts have been documented through global-scale General Circular Models (GCM). This study examined the future estimated climate generated from the CMIP5 model of the globe’s climate of four greenhouse gas scenarios in the Brantas Hulu watershed and studied the consequences for the agricultural climate suitability. The study exploited the 18 climate calculation models at the regional level by focusing on RCP 4.5, the development scenario considered in Indonesia’s climate action. During the 2000-2099 predictions, temperature and precipitation increased in all models. If this increase continues to be experienced without efforts for proper mitigation and adaptation plans, the disruption in agricultural products might pose a major consequence for food security.

Ecological niche modelling of Indigofera oblongifolia (Forssk.): a global machine learning assessment using climatic and non-climatic predictors

Climate change and other extinction facilitators have caused significant shifts in the distribution patterns of many species during the past few decades. Restoring and protecting lesser-known species may be more challenging without adequate biogeographical information. To address this knowledge gap, the current study set out to determine the global spatial distribution patterns of Indigofera oblongifolia (Forssk) a relatively lesser-known leguminous species. This was accomplished by utilizing three distinct bioclimatic temporal frames (current, 2050, and 2070) and four greenhouse gas scenarios (RCPs 2.6, 4.5, 6.0, and 8.5), in addition to non-climatic predictors such as global livestock population, human modification of terrestrial ecosystems, and global fertilizers application (nitrogen and phosphorus). Furthermore, we evaluate the degree of indigenousness using the geographical area, habitat suitability categories, and number of polygons. This research reveals that climatic predictors outperform non-climatic predictors in terms of improving model quality. Precipitation Seasonality is one of the most important factors influencing this species' optimum habitat suitability up to 150 mm for the current, 2050 RCP 8.5 and 2070-RCPs 2.6, 4.5, and 8.5. Our ellipsoid niche modelling extends the range of precipitation during the wettest quarter and maximum temperature during the warmest month to 637 mm and 26.5–31.80 degrees Celsius, respectively. India has a higher indigenous score in the optimal class than the African region. This findings suggest that the species in question tends to occupy contiguous regions in Africa, while in India, it is dispersed into several smaller meta-populations.

Future water storage changes over the Mediterranean, Middle East, and North Africa in response to global warming and stratospheric aerosol intervention

Abstract. Water storage plays a profound role in the lives of people across the Middle East and North Africa (MENA) as it is the most water-stressed region worldwide. The lands around the Caspian and Mediterranean seas are simulated to be very sensitive to future climate warming. Available water capacity depends on hydroclimate variables such as temperature and precipitation that will depend on socioeconomic pathways and changes in climate. This work explores changes in both the mean and extreme terrestrial water storage (TWS) under an unmitigated greenhouse gas (GHG) scenario (SSP5-8.5) and stratospheric aerosol intervention (SAI) designed to offset GHG-induced warming above 1.5 ∘C and compares both with historical period simulations. Both mean TWS and extreme TWS are projected to significantly decrease under SSP5-8.5 over the domain, except for the Arabian Peninsula, particularly in the wetter lands around the Caspian and Mediterranean seas. Relative to global warming, SAI partially ameliorates the decreased mean TWS in the wet regions, while it has no significant effect on the increased TWS in drier lands. In the entire domain studied, the mean TWS is larger under SAI than pure GHG forcing, mainly due to the significant cooling and, in turn, a substantial decrease in evapotranspiration under SAI relative to SSP5-8.5. Changes in extreme water storage excursions under global warming are reduced by SAI. Extreme TWS under both future climate scenarios is larger than throughout the historical period across Iran, Iraq, and the Arabian Peninsula, but the response of the more continental eastern North Africa hyper-arid climate is different from the neighboring dry lands. In the latter case, we note a reduction in the mean TWS trend under both GHG and SAI scenarios, with extreme TWS values also showing a decline compared to historical conditions.

The Indonesian Throughflow circulation under solar geoengineering

Abstract. The Indonesia Throughflow (ITF) is the only low-latitude channel between the Pacific and Indian oceans, and its variability has important effects on global climate and biogeochemical cycles. Climate models consistently predict a decline in ITF transport under global warming, but it has not yet been examined under solar geoengineering scenarios. We use standard parameterized methods for estimating the ITF – the Amended Island Rule and buoyancy forcing – to investigate the ITF under the SSP2-4.5 and SSP5-8.5 greenhouse gas scenarios and the geoengineering experiments G6solar and G6sulfur, which reduce net global mean radiative forcing from SSP5-8.5 levels to SSP2-4.5 levels using solar dimming and sulfate aerosol injection strategies, respectively. Six-model ensemble-mean projections for 2080–2100 show reductions of 19 % under the G6solar scenario and 28 % under the G6sulfur scenario relative to the historical (1980–2014) ITF, which should be compared with reductions of 23 % and 27 % under SSP2-4.5 and SSP5-8.5. Despite standard deviations amounting to 5 %–8 % for each scenario, all scenarios are significantly different from each other (p<0.05) when the whole 2020–2100 simulation period is considered. Thus, significant weakening of the ITF occurs under all scenarios, but G6solar more closely approximates SSP2-4.5 than G6sulfur does. In contrast with the other three scenarios, which show only reductions in forcing due to ocean upwelling, the G6sulfur experiment shows a large reduction in ocean surface wind stress forcing accounting for 47 % (38 %–65 % across the model range) of the decline in wind + upwelling-driven ITF transport. There are also reductions in deep-sea upwelling in extratropical western boundary currents.

Climate Change Effect on Freeze-thaw Load in Finland

Freeze-thaw damage is one of the major degradation mechanisms of climate exposed porous rock-based building materials in existing Finnish building stock. In recent studies, it has been shown that not only the amount of freeze-thaw cycles but especially the amount of wind-driven rain (WDR) before freeze-thaw cycles has a major effect on the rate of freeze-thaw damage in concrete structures. In this study, freeze-thaw cycles after a rain event, the average annual amount of WDR before freeze-thaw cycles and the average amount of WDR before each cycle is calculated in different locations in Finland. The calculations are made for present and projected 2050 and 2080 climates with three greenhouse gas scenarios: RCP2.6, RCP4,5 and RCP8.5. Based on the results, the freeze-thaw load is decreasing in coastal and southern areas and staying at current level or increasing in northern parts of Finland. In addition, the level of freeze-thaw load is getting less direction or geographically dependent. The results strongly indicate that the exposure level might be decreasing in coastal area and southern parts of Finland because both the freeze-thaw cycles and the annual amount of WDR before cycles are decreasing. However, an average amount of WDR before a freeze-thaw cycle is actually increasing and so, the intensity of freeze-thaw attack is not decreasing. Thus, for the future climates freeze-thaw durability of porous rock-based structures should be still emphasised.

Changes in apparent temperature and PM2.5 around the Beijing–Tianjin megalopolis under greenhouse gas and stratospheric aerosol intervention scenarios

Abstract. Apparent temperature (AP) and ground-level aerosol pollution (PM2.5) are important factors in human health, particularly in rapidly growing urban centers in the developing world. We quantify how changes in apparent temperature – that is, a combination of 2 m air temperature, relative humidity, surface wind speed, and PM2.5 concentrations – that depend on the same meteorological factors along with future industrial emission policy may impact people in the greater Beijing region. Four Earth system model (ESM) simulations of the modest greenhouse emissions RCP4.5 (Representative Concentration Pathway), the “business-as-usual” RCP8.5, and the stratospheric aerosol intervention G4 geoengineering scenarios are downscaled using both a 10 km resolution dynamic model (Weather Research and Forecasting, WRF) and a statistical approach (Inter-Sectoral Impact Model Intercomparison Project – ISIMIP). We use multiple linear regression models to simulate changes in PM2.5 and the contributions meteorological factors make in controlling seasonal AP and PM2.5. WRF produces warmer winters and cooler summers than ISIMIP both now and in the future. These differences mean that estimates of numbers of days with extreme apparent temperatures vary systematically with downscaling method, as well as between climate models and scenarios. Air temperature changes dominate differences in apparent temperatures between future scenarios even more than they do at present because the reductions in humidity expected under solar geoengineering are overwhelmed by rising vapor pressure due to rising temperatures and the lower wind speeds expected in the region in all future scenarios. Compared with the 2010s, the PM2.5 concentration is projected to decrease by 5.4 µg m−3 in the Beijing–Tianjin province under the G4 scenario during the 2060s from the WRF downscaling but decrease by 7.6 µg m−3 using ISIMIP. The relative risk of five diseases decreases by 1.1 %–6.7 % in G4, RCP4.5, and RCP8.5 using ISIMIP but has a smaller decrease (0.7 %–5.2 %) using WRF. Temperature and humidity differences between scenarios change the relative risk of disease from PM2.5 such that G4 results in 1 %–3 % higher health risks than RCP4.5. Urban centers see larger rises in extreme apparent temperatures than rural surroundings due to differences in land surface type, and since these are also the most densely populated, health impacts will be dominated by the larger rises in apparent temperatures in these urban areas.

Thermosteric and dynamic sea level under solar geoengineering

The IPCC sixth assessment report forecasts sea level rise (SLR) of up to 2 m along coasts by 2100 relative to 1995–2014 following business as usual (SSP585) scenarios. Geoengineering may reduce this threat. We use five Earth System Models simulations of two different solar geoengineering methods (solar dimming and stratospheric sulfate aerosol injection), that offset radiative forcing differences between SSP585 “no-mitigation” and the modest mitigation SSP245 greenhouse gas scenarios, to analyze the impact on global mean thermosteric and dynamic regional sea levels. By 2080–2099, both forms of geoengineering reduce global mean thermosteric sea level by 36–41% (11.2–12.6 cm) relative to SSP585, bringing the global mean SLR under SSP585 in line with that under SSP245, but do not perfectly restore regional SLR patterns. Some of the largest reductions (∼18 cm) are on densely populated coasts of eastern Northern America and Japan and along vulnerable Arctic coastal permafrost.

Predictive ecological niche modelling of an important bio-control agent: Trichoderma harzianum (Rifai) using the MaxEnt machine learning tools with climatic and non-climatic predictors

ABSTRACT Ecological niche model (ENM) pertains to a class of methodologies that utilise occurrence data alongside environmental data to formulate a correlative model of the environmental circumstances that satisfy a species’ ecological requirements. In the current study, ENM was employed to ascertain the types of habitat for Trichoderma harzianum using machine learning algorithm known as MaxEnt Entropy. Our line of reasoning posits that the efficacy of T. harzianum as a bio-control agent can be enhanced, alongside the advancement of host/crop development and metabolic processes, through its deliberate introduction into geographically appropriate habitats. ENM was performed on 92 spatially thinned presence points of this species across India, considering three bio-climatic time periods (present, 2050, and 2070) and four greenhouse gas scenarios (known as representative concentration pathways RCPs). Non-bioclimatic factors include ecosystem rooting depths (ERD), total plant available water storage capacity (TPAWSC), habitat heterogeneity indices (HHI), land use land cover (LULC) and to soil variables at four depths. Energy-related factors, like Isothermality and minimum temperature of coldest month, were shown to be the most essential for the habitat appropriateness of this species during the current bio-climatic period. Future climate predictions and their associated RCPs revealed that water-related variables, like precipitation of wettest quarter, were the most influential. Non-climatic elements that were shown to have significant impact included soil pH, maximum diversity indices, forest and grassland types, TPAWSC, ERD (95%). Our analysis showed that this species will always find optimal suitability sites in northern eastern India with almost all predictors except root zone variables.

Arctic stratosphere changes in the 21st century in the Earth system model SOCOLv4

Two ensemble simulations of a new Earth system model (ESM) SOCOLv4 (SOlar Climate Ozone Links, version 4) for the period from 2015 to 2099 under moderate (SSP2-4.5) and severe (SSP5-8.5) scenarios of greenhouse gas (GHG) emission growth were analyzed to investigate changes in key dynamical processes relevant for Arctic stratospheric ozone. The model shows a 5–10 K cooling and 5%–20% humidity increase in the Arctic lower–upper stratosphere in March (when the most considerable ozone depletion may occur) between 2080–2099 and 2015–2034. The minimal temperature in the lower polar stratosphere in March, which defines the strength of ozone depletion, appears when the zonal mean meridional heat flux in the lower stratosphere in the preceding January–February is the lowest. In the late 21st century, the strengthening of the zonal mean meridional heat flux with a maximum of up to 20 K m/s (∼25%) in the upper stratosphere close to 70°N in January–February is obtained in the moderate scenario of GHG emission, while only a slight increase in this parameter over 50 N–60 N with the maximum up to 5 K m/s in the upper stratosphere and a decrease with the comparable values over the high latitudes is revealed in the severe GHG emission scenario. Although the model simulations confirm the expected ozone layer recovery, particularly total ozone minimum values inside the Arctic polar cap in March throughout the 21st century are characterized by a positive trend in both scenarios, the large-scale negative ozone anomalies in March up to −80 DU–100 DU, comparable to the second lowest ones observed in March 2011 but weaker than record values in March 2020, are possible in the Arctic until the late 21st century. The volume of low stratospheric air with temperatures below the solid nitric acid trihydrate polar stratospheric cloud (PSC NAT) formation threshold is reconstructed from 3D potential vorticity and temperature fields inside the stratospheric polar vortex. A significant positive trend is shown in this parameter in March in the SSP5-8.5 scenario. Furthermore, according to the model data, an increase in the polar vortex isolation throughout the 21st century indicates its possible strengthening in the lower stratosphere. Positive trends of the surface area density (SAD) of PSC NAT particles in March in the lower Arctic stratosphere over the period of 2015–2099 are significant in the severe GHG emission scenario. The polar vortex longitudinal shift toward northern Eurasia is expected in the lower stratosphere in the late 21st century in both scenarios. The statistically significant long-term stratospheric sulfuric acid aerosol trend in March is expected only in the SSP5.8-5 scenario, most probably due to cooler stratosphere and stronger Brewer–Dobson circulation intensification. Both scenarios predict an increase in the residual meridional circulation (RMC) in March by the end of the 21st century. In some regions of the stratosphere, the RMC enhancement under the severe GHG scenario can exceed 20%.

Climate Change and Potential Demise of the Indian Deserts

AbstractIn contrast to the “wet gets wetter and dry gets drier” paradigm, here, using observations and climate model simulations, we show that the mean rainfall over the semi‐arid northwest parts of India and Pakistan has increased by 10%–50% during 1901–2015 and is expected to increase by 50%–200% under moderate greenhouse gas (GHG) scenarios. The GHG forcing primarily drives the westward expansion of the Indian summer monsoon rainfall (ISMR) and is facilitated by a westward expansion of the Indian Ocean (IO) warm pool. Mechanistically, the westward expansion of ISMR is a consequence of the episodic genesis over IO and the northward propagation of an expanded Inter‐Tropical Convergence Zone on a sub‐seasonal time scale. While an adaptation strategy to increased hydrological disasters is a must, harnessing the augmented rainfall would lead to a substantial boost in food productivity, bringing transformative changes in the socio‐economic condition of people in the region.

Modelling the climate change impacts on river discharge and inundation extent in the Magdalena River basin – Colombia

ABSTRACT Climate change may have significant impacts on water balance and may considerably influence flooding dynamics of river systems by increasing extreme precipitation. This study evaluates the potential effects of climate change on river discharge and inundation in the Magdalena River basin, the main river in Colombia, using the synergy between the MGB (Modelo de Grandes Bacias) hydrological–hydrodynamic model and downscaled Eta-regional climate model (RCM) projections based on four global climate models (GCMs): BESM (Brazilian Earth System Model), CanESM2 (Canadian Earth System Model), MIROC5 (Model for Interdisciplinary Research on Climate Version Five), and HadGEM2-ES (Hadley Centre Global Environment Model version 2). We used two different greenhouse gas scenarios (RCP4.5 and RCP8.5 (Representative Concentration Pathway)) for the “historical” (1986–2005) and “mid-term prospective” (2046–2065) periods. Model results for the “mid-term prospective” period under scenarios RCP4.5 and RCP8.5 indicate increase in mean river discharges in the east portion of the basin, decreased river discharges (mainly in the dry season) in the upper Magdalena basin, and increased inundation extent. By coupling hydrological–hydrodynamic and GCMs/RCMs models, modelling frameworks like the one used in this study provide an effective management tool for stakeholders interested in potential climate change impacts on tropical river basins.

Climate Change Impacts on Surface Heat Fluxes in a Deep Monomictic Lake

AbstractTurbulent and radiative energy exchanges between lakes and the atmosphere play an important role in determining the process of lake‐mixing and stratification, including how lakes respond to climate and to climate change. Here we used a one‐dimensional hydrodynamic lake model to assess seasonal impacts of climate change on individual surface heat flux components in Lough Feeagh, Ireland, a deep, monomictic lake. We drove the lake model with an ensemble of outputs from four climate models under three future greenhouse gas scenarios from 1976 to 2099. In these experiments, the results showed significant increases in the radiative budget that were largely counteracted by significant increases in the turbulent fluxes. The combined change in the individual surface heat fluxes led to a change in the total surface heat flux that was small, but sufficient to lead to significant changes in the volume‐weighted average lake temperature. The largest projected changes in total surface heat fluxes were in spring and autumn. Both spring heating and autumnal cooling significantly decreased under future climate conditions, while changes to total surface heat fluxes in winter and summer were an order of magnitude lower. This led to counter‐intuitive results that, in a warming world, there would be less heat not more entering Lough Feeagh during the springtime, and little change in net heating over the summer or winter compared to natural climate conditions, projected increases in the volume‐weighted average lake temperature were found to be largely due to reduced heat loss during autumn.

Future scenarios in the former oil capital: coastal flooding and social vulnerability in Macaé, RJ.

The accelerated urban growth in Macaé had important consequences on socio-spatial organization, especially about housing spaces that became increasingly difficult to be accessed by the low-income population. The most devalued lands, such as mangroves and floodplains, were occupied by the low-income population. The proposal highlighted in this project focuses directly on the problem of rising sea levels and flooding in the urban space of Macaé, which is of social interest. A simulation of future scenarios with sea level rise above the current one, allowing the identification of areas flooded by marine transgression on a time scale of 100years (for the year 2100). For this, the rate was chosen for the simulation: the greenhouse gas scenario RCP8.5, as given in IPCC's Fifth Assessment Report (AR5) of 2014. A radiative forcing that corresponds to more than 700ppm CO2-eq, but less than 1500ppm, the projected increase is 1m to more than 3m (medium confidence) and more than 3m (medium confidence). This assessment is based on the average confidence in the contribution from thermal expansion and low confidence in the modeled contribution modeled contribution of the ice sheets. Therefore, the climate change-induced global mean sea level rise is caused by thermal expansion of ocean water and ocean mass gain, the latter being mainly due to a decrease in land ice mass. The estimated sea-level rise used for the projection of this study is 2.15, as proposed by Grinsted et al. in 2009.

Projected effects of climate change on marine ecosystems in Southeast Asian seas

The seas of Southeast Asia are home to some of the world’s most diverse ecosystems and resources that support the livelihoods of millions of people. Climate change will bring temperature changes, acidification and other environmental change, with uncertain consequences for human and natural systems, but there has been little regional-scale climate modelling of the marine ecosystem. We present initial dynamically downscaled projections using a biogeochemical model suitable for coastal and shelf seas. A coupled physical-biogeochemical model with a resolution of 0.1° (approximately 11 km) was used to create projections of future environmental conditions under moderate (RCP4.5) and high (RCP8.5) greenhouse gas scenarios. Changes for different parts of the region are presented, including four sensitive coastal sites of key importance for biodiversity and sustainable development: UNESCO Biosphere Reserves at Cu Lao Cham-Hoi An in Vietnam, Palawan in the Philippines and Taka Bonerate-Kepulauan Selayar in Indonesia, and coastal waters of Sabah, Malaysia, which include several marine parks. The projections show a sea that is warming by 1.1 to 2.9°C through the 21st century, with dissolved oxygen decreasing by 5 to 13 mmol m-3 and changes in many other environmental variables. The changes reach all parts of the water column and many places are projected to experience conditions well outside the range seen at the start of the century. The resulting damage to coral reefs and altered species distribution would have consequences for biodiversity, the livelihoods of small-scale fishers and the food security of coastal communities. Further work using a range of global models and regional models with different biogeochemical components is needed to provide confidence levels, and we suggest some ways forward. Projections of this type serve as a key tool for communities and policymakers as they plan how they will adapt to the challenge of climate change.

An integrated modeling approach for considering wildlife reintroduction in the face of climate uncertainty: A case for the North Cascades grizzly bear

As Earth faces a crisis of biodiversity loss, reintroduction of imperiled species has become an important tool toward mitigating extirpation. Current habitat quality for a reintroduced species may change dramatically under future climate scenarios, undermining or supporting species conservation efforts. Models designed to understand such change must consider the niche plasticity of a species to assess the costs and benefits of reintroduction. We integrated spatially-explicit individual-based population models with a dynamic vegetation model, using combinations of global climate models and greenhouse gas scenarios to better understand potential future carrying capacity for grizzly bears in the North Cascades Ecosystem (NCE). We estimated the ecosystem could support a grizzly bear population under several climate change scenarios through the 2080s, with the amount of high quality habitat increasing across all models, scenarios, and time periods, as compared to current conditions. Projected future habitat quality remained consistent or increased slightly along the eastern portion of the ecosystem, and increased along its central and western portions, for a net increase in high quality habitat through time. At the most plausible female home range size of 280 km2, we estimated carrying capacity would increase from a baseline of 139 female bears to 241–289 female bears. Estimated changes in habitat over time could increase grizzly bear density to 20–22 bears/1000 km2 (males and females) from the previous estimate of 17 bears/1000 km2. Species with broad ecological niches (i.e., generalists), such as grizzly bears, may be especially good candidates for reintroduction efforts in some ecosystems. Our integrated model structure provides an innovative tool for advancing reintroduction initiatives while considering some long-term risks for species.