Climate Change Projections Research Articles

Understanding Climate Change and Anthropogenic Impacts on the Salinization of Low‐Lying Coastal Groundwater Systems

AbstractFresh coastal groundwater is a valuable water resource of global significance, but its quality is threatened by saltwater intrusion. Excessive groundwater abstraction, sea‐level rise (SLR), land subsidence and other climate‐related factors are expected to accelerate this process in the future. The objective of this study is to (a) quantify the impact of projected climate change and (b) explore the role of individual hydrogeological boundaries on groundwater salinization of low‐lying coastal groundwater systems until 2100 CE. We employ numerical density‐dependent groundwater flow and salt transport modeling for this purpose, using Northwestern Germany as a case. Separate model variants are constructed and forced with climate data, that is, projected SLR and groundwater recharge, as well as likely ranges of other hydrogeological boundaries, including land subsidence, abstraction rates and drain levels. We find that autonomous salinization in the marsh areas, resulting from non‐equilibrium of the present‐day groundwater salinity distribution with current boundary conditions, is responsible for >50% of the salinization increase until 2100 CE. Sea‐level rise, land subsidence and drain levels are the other major factors controlling salinization. We further show that salinization of the water resources is a potential threat to coastal water users, including water suppliers and the agrarian sector, as well as coastal ecosystems. Regional‐scale uplifting of drain levels is identified as an efficient measure to mitigate salinization of deep and shallow groundwater in the future. The presented modeling approach highlights the consequences of climate change and anthropogenic impacts for coastal salinization, supporting the timely development of mitigation strategies.

Indonesia's economic and environmental resilience in the face of climate change: Analysis and implementation strategies

Backgorund: Climate change is a significant threat to Indonesia, an archipelago that is vulnerable to the negative impacts of this phenomenon. This study aims to identify the effects of climate change in Indonesia and evaluate mitigation and adaptation strategies needed to improve economic and environmental resilience. Based on climate change projections, increases in surface temperature, changes in rainfall patterns, sea level rise, and changes in water salinity have negative impacts on various sectors such as agriculture, fisheries, infrastructure, and public health. Method: The research method includes secondary data analysis from various official sources and a study of relevant literature, with an analytical descriptive approach to identify critical challenges and necessary strategies. Findings: The results show that limited fiscal space and the need for budgetary reform are significant challenges that need to be addressed through the introduction of a carbon tax, budgetary incentives for green technologies, and the removal of fossil fuel subsidies. In addition, mobilization of non-budget funding sources is needed to support green projects, with strategies such as the development of public-private partnerships, access to international funds, and technical capacity building. Conclusion: In conclusion, implementation of the recommended mitigation and adaptation strategies can increase Indonesia's resilience to climate change, reduce its risks and negative impacts, and ensure the sustainability of economic and social development. Novelty/Originality of this study: This research provides practical guidance for policymakers to develop effective strategies to deal with climate change

Blue and green water availability under climate change in arid and semi-arid regions

Challenges involving water scarcity have raised concerns about sustainability and human well-being in many regions of Iran. Uncertainty related to the effects of climate change further complicates the use of projections for water resources planning. Hence, investigating the impacts of climate change on water resources is essential for their efficient management. In the present study, water availability was assessed under different climate change projections using eight CMIP6 General Circulation Models (GCMs) to create a multi-model ensemble of well-performing GCMs over the Hamedan-Bahar watershed in western Iran for three futures, near (2026 to 2050), mid (2051 to 2075), and far (2076 to 2100). Impacts of climate change on blue and green water availability was assessed by coupling Soil and Water Assessment Tool (SWAT) with modelled climate change projections and applying distribution mapping bias correction under three Shared Socioeconomic Pathways Scenarios (SSPs). The results showed that three GCMs (MIROC6, CMCC-ESM2, and NorESM2-MM) agreed well with observed climate in the region. The mean annual precipitation was projected to decrease at most by 16.3% under the SSP5–8.5 scenario during mid-future. Maximum and minimum temperatures are expected to increase by 2.3 and 2.4 °C, respectively, under the SSP5–8.5 scenario for the far future. The highest reductions of green and blue water storage and blue water flow were projected at 22%, 28.5% and 35%, respectively, under the SSP5–8.5 scenario during the mid-future. In contrast, green flow was projected to increase by 18% under SSP5–8.5 during the far future. Thus, the water resources of Hamedan-Bahar are sensitive to future climatic changes requiring considerations for adaptation strategies to mitigate water deficits.

Potential contribution of water management practices under intensive crop production to climate-change-associated global warming

Optimizing water management practices to mitigate greenhouse gas (GHG) emissions in agroecosystems is of increasing interest under climate change. However, previous studies have focused more on paddy fields, little is known as to how water table management in subsurface drained fields or how irrigation practices in humid areas might affect the global warming potential (GWP). Drawing upon experimental data from four intensive crop production sites in Eastern Canada operating under different water management practices, the DeNitrification-DeComposition (DNDC) biogeochemical model was used to assess potential GHG emissions under twelve different sets of General Circulation Models coupled with Regional Climate Models (GCM-RCM) climate projections (2046–2075). Simulations showed that water table control/sub-irrigation and sprinkler irrigation might decrease GWP by allowing greater soil organic carbon (SOC) sequestration, despite increased N2O and CO2 emissions than non-irrigated systems. While drip irrigation marginally increased the SOC sequestration, GWP still increased because the C gains from the residues generated by the greater crop biomass were offset by increased CO2 and N2O emissions. Compared with surface drip irrigation, subsurface drip irrigation reduced the GWP by reducing N2O emissions, as well as increasing crop yield and SOC stock. Although greater crop biomass was expected to return to soil under projected climate change, simulations showed a consistent increase in the GWP of tomato cropping system alone under climate change.

Climate Change Projections in the Upper Awash River Basin of Ethiopia Using Statistical Downscaling Model

Climate Change Projections in the Upper Awash River Basin of Ethiopia Using Statistical Downscaling Model

China's onshore wind energy potential in the context of climate change

China has great potential for developing renewable energy to achieve its carbon neutrality goals. Orderly development of renewable energy is essential to enhance resource utilization efficiency and ensure safety during the energy system transition process. This study presents a thorough assessment of China's onshore wind power potential by considering the land suitability, the potential and temporal characteristics, and the impacts of climate change. The high-resolution maps combining wind resources with land conditions and climate scenarios are produced to provide insights into system planning, grid integration, and flexibility management. The results show that the capacity potential of onshore wind energy in China is 9.6 TW with an annual generation of 12.6 PWh, and 83 % of total capacity has a cost advantage with the levelized cost lower than the 60 $/MWh threshold. By comprehensively considering geographical, economic, and social criteria, around 8.1 % of the national territorial area is identified as the most suitable area for wind power development, primarily in Inner Mongolia and Xinjiang. The annual electricity generation from these areas can fulfill nearly 69 % of the nation's electricity demand. Future climate change projections indicate a remarkable generalized drop by 18 % in the north and a slight increase by 7 % in the south under the RCP 8.5 scenario. However, significant changes in wind resources are mostly within restricted areas, suggesting that future climate change would like to bring negative but limited impacts on wind power production in China.

EPA awards cash to climate change projects

EPA awards cash to climate change projects

Projecting Climate Change Impact on Precipitation Patterns during Different Growth Stages of Rainfed Wheat Crop in the Pothwar Plateau, Pakistan

In rainfed areas, precipitation variations directly impact wheat growth stages such as emergence, tillering, jointing and booting, and maturity. Evaluating the impact of climate change on precipitation patterns during these critical growth stages is crucial for adapting climate change and ensuring global food security. In this study, projections of five General Circulation models (GCMs) under two shared socioeconomic pathways (SSPs) were used to predict the changing characteristics of precipitation during four main growth stages of wheat in the rainfed region of the Pothwar Plateau, Pakistan. Historical datasets of daily precipitation at six weather stations were analyzed to check the past changes in the precipitation patterns. During the baseline period (1985–2014), the annual average precipitation decreased at a rate of −9.75 mm/decade, while the amount of precipitation during the rabi season (wheat-growing season) decreased at a rate of −20.47 mm/decade. An increase in the precipitation was found during the fourth (flowering) stage of crop growth, while the first three stages experienced a decrease in the precipitation amount. The multimodal ensembled data, under the SSP2-4.5 scenario, revealed a significant decline (at the rate of −16.63 mm/decade) in the future annual precipitation. However, it is projected that, under SSP2-4.5, there may be a slight increase (4.03 mm/decade) in the total precipitation amount during the future rabi season. Under the SSP5-8.5 scenario, average annual precipitation exhibited a slightly increasing trend, increasing by 1.0 mm/decade. However, during the rabi season, there was a possibility of a decrease in precipitation amount, with a rate of 11.64 mm/decade. It is also expected that the precipitation amount may vary significantly during the crown root initiation, jointing and booting, and flowering stages in the near future. These results provide a framework for the planning of wheat production in the Pothwar region of Pakistan, taking into account the potential impact of shifting weather patterns, particularly in terms of uneven precipitation.

Drivers of seasonal rainfall variability over the Angolan and Namibian plateaus

AbstractSouthern Africa has been strongly affected by ongoing climate change in recent decades. Rainfall variability is modulated by regional patterns of moisture advection and convergence in the lower troposphere. Using reanalysis, ground and satellite‐based rainfall products and observations from 10 weather stations, we perform a synoptic and climatological analysis focussing on atmospheric circulation, moisture transport and their relationship with rainfall anomalies over the Angolan and Namibian Plateau region. Results clearly show that a stronger (weaker) Zambezi low level jet (LLJ) magnitudes are associated with above (below) normal rainfalls over the main Angolan and Namibian plateaus. With lower confidence, a stronger Limpopo LLJ may also lead to enhanced rainfall over Namibia and southeast Angola. The Zambezi LLJ moisture fluxes are moderately controlled by Mozambique Chanel Trough and Angola Low intensities, while the Limpopo LLJ intensities have very low influence from the Mozambique Chanel Trough and Angola Low, respectively. The Angola Low in its tropical phase is associated with deeper moisture convergence and stronger vertical velocities, leading to higher amounts of precipitable water within the air column, thus enhancing precipitation over the region. It is shown that the major moisture source of rainfall, which is advected to via the Zambezi LLJ, is the Indian Ocean. Meanwhile, the Atlantic Ocean plays a minor role. Given the current lack of observations and projected climate change, further research and investments are urgently needed in the region, for example, regarding the expansion of the surface data network.

Realistic representation of mixed-phase clouds increases projected climate warming

Clouds are the main source of uncertainties when projecting climate change. Mixed-phase clouds that contain ice and supercooled-liquid particles are especially hard to constrain, and climate models neither agree on their phase nor their spatial extent. This is problematic, as models that underestimate contemporary supercooled-liquid in mixed-phase clouds will underestimate future warming. Furthermore, it has recently been shown that supercooled-liquid water in mixed-phase clouds is not homogeneously-mixed, neither vertically nor horizontally. However, while there have been attempts at observationally constraining mixed-phase clouds to constrain uncertainties in future warming, all studies only use the phase of the interior of mixed-phase clouds. Here we show, using novel satellite observations that distinguish between cloud-top and interior phase in mixed-phase clouds, that mixed-phase clouds are more liquid at the cloud top globally. We use these observations to constrain the cloud top phase in addition to the interior in a global climate model, leading to +1 °C more 21st century warming in NorESM2 SSP5-8.5 climate projections. We anticipate that the difference between cloud top and interior phase in mixed-phase clouds is an important new target metric for future climate model development, because similar mixed-phase clouds related biases in future warming are likely present in many climate models.

Modelling the multiple action pathways of projected climate change on the Pacific cod (Gadus macrocephalus) early life stages

Understanding how future ocean conditions will impact early life stages and population recruitment of fishes is critical for adapting fisheries communities to climate change. In this study, we incorporated projected changes in physical and biological ecosystem dynamics from an oceanographic model into a mechanistic individual-based model for larval and juvenile stages of the Pacific cod (Gadus macrocephalus) in the eastern Bering Sea. We particularly investigated the impacts of ocean currents, temperature, prey density, and pCO2 on the hatching success, growth, survival, and spatial distribution of this species during 2021–2100. We evaluated two CO2 emission scenarios: RCP8.5 (high CO2 emissions, low mitigation efforts) and RCP4.5 (medium CO2 emissions and mitigation efforts). We found that the increase in temperature and decrease in prey density were the main drivers of faster growth rates and lower survival through increased starvation by the end of the century. Conversely, pCO2 had negligible impacts, which suggests that this species might be resilient to ocean acidification. The largest effects were observed under the high CO2 emission scenario, while the RCP4.5 projections displayed minimal impacts. We also identified an area with favourable conditions in the southeastern Bering Sea that will likely persist in future decades. This study provides relevant information on the future impacts of climate change on Pacific cod, and our results can be used to implement and inform climate-ready management for this important stock in Alaska.

Dynamical downscaling CMIP6 models over New Zealand: added value of climatology and extremes

Dynamical downscaling provides physics-based high-resolution climate change projections across regional and local scales. This is particularly important for island nations characterized by complex terrain, where the coarse resolution of global climate model (GCM) output often prohibits direct use. One of the main motivations for dynamical downscaling is to reduce biases relative to the host GCM at the local scale, which can be quantified through assessing ‘added value’. However, added value from downscaling is not guaranteed; quantifying this can help users make informed decisions about how best to use available climate projection data. Here we describe the experiment design of the updated national climate projections for New Zealand based on dynamical downscaling. The global non-hydrostatic Conformal Cubic Atmospheric Model (CCAM) is primarily used for downscaling, with a global stretched grid targeting high resolution over New Zealand (12-km) and the wider South Pacific region (12–35-km). Focusing on the historical simulations, we assess added value for a range of metrics, climatological fields, extreme indices, and tropical cyclones. The main strengths of the downscaling include generally large improvements relative to the host GCM for temperature and orographic precipitation. Inter-annual variability in temperature is well captured across New Zealand, and several temperature and precipitation-based extreme indices show large improvements. The representation of tropical cyclones reaching at least category 2 intensity is generally improved relative to the large consistent under-representation in the host GCMs. The remaining biases are explored and discussed forming the basis for ongoing bias-correction work.

An Overview of the Role of Forests in Climate Change Mitigation

Nowadays, climate change is recognized as one of the biggest problems the world is facing, posing a potential threat to the environment and almost all aspects of human life. Since the United Nations Framework Convention on Climate Change in 1992, many efforts have been made to mitigate climate change, with no considerable results. According to climate change projections, temperatures will continue to rise, and extreme weather events will become more frequent, prolonged, and intense. Reflecting these concerns, the 2015 Paris Agreement was adopted as the cornerstone for reducing the impact of climate change, aiming to limit global warming below 2 °C and even keep the temperature rise below 1.5 °C. To achieve this international goal, focused mitigation actions will be required. Climate change has a strong impact on forests, enhancing their growth but also posing risks to them. Conversely, forests can mitigate climate change, as they have a considerable impact on global surface temperatures through their influence on the land–atmosphere energy exchange and the absorption of vast amounts of CO2 through photosynthesis. Consequently, afforestation and reforestation have become integral components of climate change mitigation strategies worldwide. This review aims to summarize the cutting-edge knowledge on the role of forests in climate change mitigation, emphasizing their carbon absorption and storage capacity. Overall, the impact of afforestation/reforestation on climate change mitigation hinges on strategic planning, implementation, and local forest conditions. Integrating afforestation and reforestation with other carbon removal technologies could enhance long-term effectiveness in carbon storage. Ultimately, effective climate change mitigation entails both restoring and establishing forests, alongside reducing greenhouse gas emissions.

MONITORING AND EVALUATION TOOLS AND PERFORMANCE OF CLIMATE CHANGE PROJECT: A CASE OF GREEN AMAYAGA PROJECT

The purpose of this research was to examine monitoring and evaluation tools and performance of climate change project, case study of Green Amayaga Project. The research was guided by the following specific objectives: to evaluate the effect of project control tools on the performance of Green Amayaga climate change project, to assess the effect of project performance reporting on the performance of Green Amayaga climate change project and to determine the effect of project results evaluation on the performance of Green Amayaga climate change project. Three theories identified in this research include goal setting theory, theory of change and evaluation theory of tree. Furthermore, the research design used both descriptive and correlation analyses. The target population was made up of 143 people while the sample size is 106 selected using simple random sampling technique and quota sampling including the beneficiaries of Green Amayaga Project. Primary data was collected using questionnaires and interview guide. The findings revealed a strong relationship between project control tools and project performance as reported by the Pearson correlation (r=0.735, p<0.05). The findings on objective two (r=0.604, p<0.05) indicates positive and significant relationship with project performance. The findings based on the third objective reported a moderate positive relationship (r=0.504, p<0.000) between project result evaluation and project performance. The regression analysis reported R2=0.810 showing that 81% of the project performance is due to the influence of the use of project M&E tools such as project control tools, project performance reporting and project result evaluation. The researcher recommends that the project managers in community-based projects such as the Green Amayaga should use the M&E tools to ensure such projects achieve their development objectives within their budget, timeframe, and scope. The researcher also recommends that progressive reporting should be adopted in order to continuously furnish the donors and other stakeholders with relevant information for decision making. KEY WORDS: Monitoring and Evaluation, M&E Tools, Climate change adaptation, Project Performance, Rwanda

Unveiling Hydrological Shifts under Projected Climate Change in Highly Irrigated Semi-Arid State of Telangana, India

Unveiling Hydrological Shifts under Projected Climate Change in Highly Irrigated Semi-Arid State of Telangana, India

Podnebne projekcije temperature zraka in padavin za porečja Ledave, Pesnice in Vipave do konca 21. stoletja

As part of the project ‚CeVoTak‘, Integrated Management of Small Water Retention and Soil Erosion Prevention Measures in Agricultural Catchments, we studied changing temperature and precipitation conditions up to the year 2100. The study was conducted on agricultural lands in the catchments of the Ledava and Pesnica rivers in the sub-Pannonian region and the Vipava river in the sub-Mediterranean region. A common climate database was used to create the climate projections - RCM (Regional Climate Model) simulations from the project EURO-CORDEX and scenarios RCP (Representative Concentration Pathway), RCP2.6, 4.5 and 8.5. The projections were prepared for three time periods 2011-2040; 2041-2070 and 2071-2100 for 6 different regional climate models for average, minimum and maximum air temperatures and precipitation. Analysis of the ensemble of model simulations for all scenarios shows similar results for the basin of all rivers, an increase in temperature (maximum in winter, minimum in spring), with high confidence for all scenarios and periods. Projections of precipitation are less reliable, but show an increase in annual precipitation due to the winter increase. The use of climate change projections with expert interpretation is essential for determining the vulnerability of individual areas and building resilience through the implementation of climate change adaptation.

Climate-Induced Migration: Conflict Resolution and Legal Efforts in Pacific, Africa, and South Asia

Climate-induced migration involves people relocating caused by detrimental climate changes affecting their living environment. Pacific, Africa, and South Asia have experienced climate-induced migration resulting from extreme weather events, sea level rise, drought and desertification, and temperature extremes. The purpose of this research is to find out in terms of conflict resolution, what legal efforts have been made by the government of the affected regions to address climate-induced migration. This study uses descriptive qualitative method and case studies. Based on the results obtained from the data, it was found that the affected governments are pursuing various legal efforts to be able to tackle climate-induced migration. Several efforts made, namely “Migration with Dignity” policy, the Pacific Adaptation to Climate Change (PACC) Project, Great Green Wall initiative, the African Union’s Regional Economic Communities (RECs), Bangladesh’s Climate Change Strategy and Action Plan (BCCSAP), the South Asian Association for Regional Cooperation (SAARC) Disaster Management Centre, and India’s National Action Plan on Climate Change (NAPCC). The regional initiatives mentioned earlier play pivotal roles in implementing these frameworks and fostering collaborative endeavors, whilst the innovative legal frameworks, guided by SMART (Specific, Measurable, Achievable, Relevant, and Time-bound) indicators, ensure that climate-induced migration is addressed effectively. To sum up, dealing with climate-induced migration requires a holistic approach involving regional collaboration and innovative legal frameworks.

Resetting tropospheric OH and CH4 lifetime with ultraviolet H2O absorption.

The decay of methyl chloroform, a banned ozone-depleting substance, has provided a clear observational metric of mean tropospheric hydroxyl radical (OH) abundance. Almost all current global chemistry models calculate about 15% too much OH and thus too rapid methane loss. Methane is a short-lived climate forcer, critical to achieving global warming targets, and this error affects our model projections of climate change. New observations of water vapor absorption in the ultraviolet region (290 to 350 nanometers) imply reductions in sunlight with key photolysis rates decreasing by 8 to 12% in the near-surface tropical atmosphere. Incorporation of this new mechanism in a chemistry-transport model reduces OH and methane loss by only 4%, but combined with other proposed mechanisms, such as tropospheric halogen chemistry (7%), we may be able to resolve this conundrum.

Robust and smart: Inference on phenotypic plasticity of Coffea canephora reveals adaptation to alternative environments

AbstractCoffee is an important crop with economic and social importance in several countries. With a daily consumption estimated at 2.2 billion cups, its sustainability is facing critical challenges given the projected climate changes. Coffea arabica, which represents ∼60% of the global market coffee is a delicate crop, quite susceptible to diseases and biotic stresses. Developing climate‐resilience cultivars is necessary, and it includes coffee plants adapted to new farming conditions that can meet the demand for biotic and abiotic tolerance and quality. In this context, Coffea canephora emerges as a potential candidate if the crop combines plasticity and cupping quality. Plant plasticity refers to adjusted phenotypic performance when grown in different environments, a fact that may help mitigate the detrimental effect of climate changes. In this study, using a multiple environment trial, we combined genomic and genotype‐by‐environment analyses to answer the following main question: How the climate effects may affect the phenotypic plasticity in C. canephora? Our contributions in this paper are fourfold: (i) we draw attention to the cupping quality and yield performance of C. canephora cultivars when evaluated in high‐altitude and cold weather, (ii) we compared C. arabica and C. canephora phenotypic plasticity and highlight genotypes with broad and specific adaptation to certain environmental conditions, and finally, (iii) using stochastic simulation, we emphasize the potential of molecular breeding in the long term in coffee. Altogether, we present an emerging view on how C. canephora could be a valid alternative for climate‐smart cultivars in a projected scenario of altered climatic conditions.

Dependence of Europe's most threatened mammals on movement to adapt to climate change.

Current rates of climate change and gloomy climate projections confront managers and conservation planners with the need to integrate climate change into already complex decision-making processes. Predicting and prioritizing climatically stable areas and the areas likely to facilitate adaptive species' range adjustments are important stages in maximizing conservation outcomes and rationalizing future land management. I determined, for the most threatened European terrestrial mammal species, the spatial adaptive trajectories (SATs) of highest expected persistence up to 2080. I devised simple spatial network indices for evaluation of species in those SATs: total persistence; proportion of SATs that offer in situ adaptation (i.e., stable refugia); number of SATs converging in a site; and relationship between SAT convergence and persistence and protected areas, the Natura 2000 and Emerald networks, and areas of low human disturbance. I compared the performance of high-persistence SATs with a scenario in which each species remained in the areas with the best climatic conditions in the baseline period. The 1000 most persistence SATs for each of the 39 species covered one fifth of Europe. The areas with the largest adaptive potential (i.e., high persistence, stability, and SAT convergence) did not always overlap for all the species. Predominantly, these regions were located in southwestern Europe, Central Europe, and Scandinavia, with some occurrences in Eastern Europe. For most species, persistence in the most climatically suitable areas during the baseline period was lower than within SATs, underscoring their reliance on adaptive movements. Importantly, conservation areas (particularly protected areas) covered only minor fractions of species persistence among SATs, and hubs of spatial climate adaptation (i.e., areas of high SAT convergence) were seriously underrepresented in most conservation areas. These results highlight the need to perform analyses on spatial species' dynamics under climate change.