SOCIOECONOMIC IMPACTS OF CLIMATE CHANGE ON U.S. WATER SUPPLIES1

ABSTRACT: A greenhouse warming would have major effects on water supplies and demands. A framework for examining the socioeconomic impacts associated with changes in the long-term availability of water is developed and applied to the hydrologic implications of the Canadian and British Hadley2 general circulation models (GCMs) for the 18 water resource regions in the conterminous United States. The climate projections of these two GCMs have very different implications for future water supplies and costs. The Canadian model suggests most of the nation would be much drier in the year 2030. Under the least-cost management scenario the drier climate could add nearly $105 billion to the estimated costs of balancing supplies and demands relative to the costs without climate change. Measures to protect instream flows and irrigation could result in significantly higher costs. In contrast, projections based on the Hadley model suggest water supplies would increase throughout much of the nation, reducing the costs of balancing water supplies with demands relative to the no-climate-change case.     

Rice versus fish revisited: On the integrated management of floodplain resources in Bangladesh

Disproportionately little attention has been paid to the dry season trade‐off between rice and (inland capture) fish production on the floodplains of Bangladesh, compared to the same trade‐off during the flood season. As the rural economy grows increasingly dominated by dry‐season irrigated rice production, and floodplain land and water come under ever‐increasing pressure during the dry winter months, there is an urgent need to focus attention on these dry months that are so critical to the survival and propagation of the floodplain resident fish, and to the poor people that depend on these fish for their livelihood. This article examines three important dry‐season natural resource constraints to floodplain livelihoods in Bangladesh, and finds a common factor at the heart of all three: rice cultivation on lands at low and very low elevations. The article articulates the system interlinkages that bind these constraints and the long‐run trend towards irrigated rice cropping on lower‐lying lands, and suggests a management approach based on locally tailored strategies to arrest this trend. Apart from its direct relevance to the floodplains of Bangladesh, which support more than 100 million people, these lessons have relevance for river floodplain systems elsewhere in the developing world, notably the Mekong Delta.     

Major climate-change issues covered by the daily newspapers of Bangladesh

Communications research scholars, political scientists, and policy analysts have significantly recognized the role of news media in reporting and portraying public issues. Nowadays, climate change is an important global environmental concern for the world communities. Study on the media coverage of climate-change issues is vitally important to know the present situation of both the global and regional climate, as well as to assess the causes, mitigation and adaptation techniques, and its adverse impacts. This study demonstrates the coverage of newspapers in Bangladesh on climate change from May 2006 through June 2009 for the three most popular newspapers of Bangladesh, namely The Prothom Alo, The Daily Ittefaq, and The Daily Star. Natural disasters was the major climate-change issue that received the most coverage, along with agriculture, biodiversity, global warming, climate change, crime, water scarcity, food scarcity, politics, wetlands, tourisms, rivers, forestry and miscellaneous issues. Local communication concerned with climate-change issues was given preference in the coverage by the newspapers throughout the study period. The study will be useful for awareness-program formulation on climate-change mitigation and adaptation in Bangladesh.     

Prospective changes in irrigation water requirements caused by agricultural expansion and climate changes in the eastern arc mountains of Kenya

Water resources and land use are closely linked with each other and with regional climate, assembling a very complex system. The understanding of the interconnecting relations involved in this system is an essential step for elaborating public policies that can effectively lead to the sustainable use of water resources. In this study, an integrated modelling framework was assembled in order to investigate potential impacts of agricultural expansion and climate changes on Irrigation Water Requirements (IWR) in the Taita Hills, Kenya. The framework comprised a land use change simulation model, a reference evapotranspiration model and synthetic precipitation datasets generated through a Monte Carlo simulation. In order to generate plausible climate change scenarios, outputs from General Climate Models were used as reference to perturbing the Monte Carlo simulations. The results indicate that throughout the next 20 years the low availability of arable lands in the hills will drive agricultural expansion to areas with higher IWR in the foothills. If current trends persist, agricultural areas will occupy roughly 60% of the study area by 2030. This expansion will increase by approximately 40% the annual water volume necessary for irrigation. Climate change may slightly decrease crops' IWR in April and November by 2030, while in May a small increase will likely be observed. The integrated assessment of these environmental changes allowed a clear identification of priority regions for land use allocation policies and water resources management.     

IMPACTS OF CLIMATE CHANGE ON AQUATIC ECOSYSTEM FUNCTIONING AND HEALTH1

ABSTRACT: We review published analyses of the effects of climate change on goods and services provided by freshwater ecosystems in the United States. Climate-induced changes must be assessed in the context of massive anthropogenic changes in water quantity and quality resulting from altered patterns of land use, water withdrawal, and species invasions; these may dwarf or exacerbate climate-induced changes. Water to meet instream needs is competing with other uses of water, and that competition is likely to be increased by climate change. We review recent predictions of the impacts of climate change on aquatic ecosystems in eight regions of North America. Impacts include warmer temperatures that alter lake mixing regimes and availability of fish habitat; changed magnitude and seasonality of runoff regimes that alter nutrient loading and limit habitat availability at low flow; and loss of prairie pothole wetlands that reduces waterfowl populations. Many of the predicted changes in aquatic ecosystems are a consequence of climatic effects on terrestrial ecosystems; shifts in riparian vegetation and hydrology are particularly critical. We review models that could be used to explore potential effects of climate change on freshwater ecosystems; these include models of instream flow, bioenergetics models, nutrient spiraling models, and models relating riverine food webs to hydrologic regime. We discuss potential ecological risks, benefits, and costs of climate change and identify information needs and model improvements that are required to improve our ability to predict and identify climate change impacts and to evaluate management options.     

Company engagement with supply chains to protect biodiversity and rare,threatened, and endangered species

Future global megatrends project a population increase of 2 billion people between 2019 and 2050 and at least 1–2 billion people added to the global middle class between 2016 and 2030. In addition, 68% of the world's population is projected to be living in urban areas by 2050. With these projected large population increases and shifts, demand for food, water, and energy is projected to grow by approximately 35, 40, and 50%, respectively, between 2010 and 2030. In addition, between 1970 and 2014 there was an estimated 60% reduction in the number of wildlife in the world and an estimated net loss of 2.9 billion birds, or 29%, in North America between 1970 and 2018. Loss of species populations and number of species is interconnected with reduced health of biodiversity and ecosystems. Human activity has been the main catalyst for these substantial declines primarily through impacts on habitats. These losses are accelerating. Since a company's supply chain environmental impacts are often as great or greater than its own direct environmental impacts, it may be prudent for companies to engage with their supply chains to protect and enhance habitats and biodiversity and protect rare, threatened, and endangered species. As one example, companies may have opportunities and strategic reasons to include requirements in their supplier codes of conduct and supplier standards for suppliers to protect biodiversity and rare, threatened, and endangered species, as well as additional requirements to expand or enhance habitats and ecosystems to increase biodiversity. This article follows one pathway that companies could pursue further and with greater speed—to engage with their supply chains to strengthen supplier codes of conduct to protect biodiversity and rare, threatened, and endangered species. The importance of forests, private land, and landscape partnerships is discussed as means to protect much more of the planet's biodiversity and rare, threatened, and endangered species. Lastly, the article identifies examples of opportunities for companies to more formally incorporate biodiversity into their business, supply chain, and sustainability strategies.     

CLIMATE CHANGE IMPACTS UNCERTAINTY FOR WATER RESOURCES IN THE SAN JOAQUIN RIVER BASIN,CALIFORNIA1

ABSTRACT: A climate change impacts assessment for water resources in the San Joaquin River region of California is presented. Regional climate projections are based on a 1 percent per year CO₂ increase relative to late 20th Century CO₂ conditions. Two global projections of this CO₂ increase scenario are considered (HadCM2 and PCM) during two future periods (2010 to 2039 and 2050 to 2079). HadCM2 projects faster warming than PCM. HadCM2 and PCM project wetter and drier conditions, respectively, relative to present climate. In the HadCM2 case, there would be increased reservoir inflows, increased storage limited by existing capacity, and increased releases for deliveries and river flows. In the PCM case, there would be decreased reservoir inflows, decreased storage and releases, and decreased deliveries. Impacts under either projection case cannot be regarded as more likely than the other. Most of the impacts uncertainty is attributable to the divergence in the precipitation projections. The range of assessed impacts is too broad to guide selection of mitigation projects. Regional planning agencies can respond by developing contingency strategies for these cases and applying the methodology herein to evaluate a broader set of CO₂ scenarios, land use projections, and operational assumptions. Improved agency access to climate projection information is necessary to support this effort.     

CLIMATE CHANGE,IRRIGATION, AND CROP RESPONSE1

ABSTRACT: A set of simulation models consisting of a weather generator, and irrigation supply, soil moisture and crop growth components was used to evaluate the impacts of climate change on irrigated corn in locations near Albany, New York, Indianapolis, Indiana, and Oklahoma City, Oklahoma. The models evaluated the combined effects of modified water demand, supply and crop management (planting date, cultivar selection, irrigation). Simulations were duplicated for 100-year weather sequences based on current (1961–1988) weather statistics, and statistics modified by outputs from the GFDL GCM runs showing the effects from doubling of atmospheric CO₂. Climate impacts differed greatly with location and management. Effects were most adverse in New York and least damaging in Indiana. At all sites, the beneficial effects of longer growing season and increased water supply were generally overcome by the detrimental impacts of increased evapotranspiration and reduced solar radiation during plant maturing stages. Adverse impacts of climate change can be substantially reduced by irrigation and appropriate selection of planting dates and cultivars.     

Global and regional potential of wastewater as a water,nutrient and energy source

There is a proactive interest in recovering water, nutrients and energy from waste streams with the increase in municipal wastewater volumes and innovations in resource recovery. Based on the synthesis of wastewater data, this study provides insights into the global and regional “potential” of wastewater as water, nutrient and energy sources while acknowledging the limitations of current resource recovery opportunities and promoting efforts to fast-track high-efficiency returns. The study estimates suggest that, currently, 380 billion m³ (m³ = 1,000 L) of wastewater are produced annually across the world which is a volume five-fold the volume of water passing through Niagara Falls annually. Wastewater production globally is expected to increase by 24% by 2030 and 51% by 2050 over the current level. Among major nutrients, 16.6 Tg (Tg = million metric ton) of nitrogen are embedded in wastewater produced worldwide annually; phosphorus stands at 3.0 Tg and potassium at 6.3 Tg. The full nutrient recovery from wastewater would offset 13.4% of the global demand for these nutrients in agriculture. Beyond nutrient recovery and economic gains, there are critical environmental benefits, such as minimizing eutrophication. At the energy front, the energy embedded in wastewater would be enough to provide electricity to 158 million households. These estimates and projections are based on the maximum theoretical amounts of water, nutrients and energy that exist in the reported municipal wastewater produced worldwide annually. Supporting resource recovery from wastewater will need a step-wise approach to address a range of constraints to deliver a high rate of return in direct support of Sustainable Development Goals (SDG) 6, 7 and 12, but also other Goals, including adaptation to climate change and efforts in advancing “net-zero” energy processes towards a green economy.     

Urban Wastewater Treatment and Reclamation for Agricultural Irrigation: The situation in Morocco and Palestine

As freshwater becomes increasingly scarce due to population growth, urbanisation and, probably, climate change, the use of wastewater in agriculture, aquaculture, groundwater recharge and in other areas will increase. In some cases, wastewater is the only water resource available to poor, subsistence-level farming communities. Although there are benefits to using wastewater in agriculture—such as better nutrition and food security for many households—uncontrolled use of wastewater is frequently associated with significant negative human health impacts. These health impacts can be minimized when good management practices are implemented. In this paper the existing situation, in relation to water resources availability, wastewater treatment and reuse in Morocco and Palestine, is presented.     

The development of a method to determine the burden of climate change on different health outcomes at a local scale: a case study in Osaka Prefecture,Japan

Climate change impacts human health in a variety of ways. Variables including the climate-related risk factor, the health outcome and location all determine the nature and extent of the impact. The existence of different pathways and endpoints presents a problem for quantifying and comparing impacts. Disability-adjusted life year (DALY) provides a common scale, whereby the impact of climate change on both acute and chronic health outcomes can be compared. This study presents a methodology to calculate the impact of climate change on human health at a local scale, using cardiovascular disease (CVD) and meteorological disaster-related injuries (DRIs) in Osaka Prefecture, Japan, as applied case studies. An additional very fine scale assessment of CVD conducted at the neighbourhood level to demonstrate the importance of conducting risk assessments at a local level. The comparative results calculated the impact of climate change in 2050 to be 16.866 DALY/100,000 population for CVD and 0.645 DALY/100,000 for meteorological DRIs. The actual impact of climate change by 2050 on CVD is judged to be higher, although the relative risk was projected to be lower (1.006, compared to 1.263 for meteorological DRIs). The fine scale assessment revealed the variations in the projected impact of climate change on CVD for all administrative zones in Osaka Prefecture. The range of impacts varied from 0 to 114.29 DALY/100,000. The results demonstrate the applicability of using DALY to quantify the impact of climate change on different health outcomes, using a transferable methodology, and provide information that enables evidence-based prioritisation of climate change adaptation strategies at a local scale.     

Diversion of the Ganges Water at Farakka and Its Effects on Salinity in Bangladesh

/ The Ganges River supplies water to the southwest region of Bangladesh mainly through one of its distributaries-the Gorai River. India commissioned a barrage on the Ganges River at Farakka in April 1975 to divert water and make the Bhagirathi-Hooghly River navigable. The diversion has reduced the dry season discharge of the Ganges and Gorai rivers in Bangladesh. Statistical analyses indicate that the changes in the dry season discharge of these rivers are significant. Reduced discharge in the Gorai River has induced accelerated sedimentation and increased salinity in the southwest region of Bangladesh. Empirical analyses demonstrate the relationship between discharge in the Gorai River and salinity. Analyses also determine the requirement of flow for the Ganges and Gorai rivers to keep salinity at threshold limits. Increased salinity has caused negative effects on agriculture, forestry, industry, and drinking water in the southwest region of Bangladesh.KEY WORDS: Bangladesh; Ganges River; Gorai River; Farakka diversion; Salinity     

Water Use Efficiency and Storage Capacity in South Asia by 2050

More than one billion South Asians are affected by water scarcity. Pressure on water resources is likely to grow as a result of population growth, urban expansion, and climate change. This paper assesses the impacts of these effects on the historical hydrological baseline, with particular focus on irrigation. A geospatial water balance model was developed for this purpose based on geo‐referenced information available in scientific public domain databases. Annual water supply and demand for a baseline period 1950–2000 were calculated and projected to 2050 using (1) outputs from 19 Global Circulation Models from the Coupled Model Intercomparison Project Phase 5 for a Representative Concentration Pathway 4.5; (2) population projections to 2050; and (3) historical land‐use patterns at the country level. Improvements in water use efficiency and storage capacity were analyzed using the Modified Water Scarcity Index of the baseline and the projected water balance in 2050 at the watershed scale.     

Artisan fishers’ perception of climate change and disasters in coastal Bangladesh

Climate change is affecting fishing communities across Bangladesh. While work has been undertaken to investigate the nature of these impacts, understanding how fishers perceive climate change at a local level, especially within developing countries, is crucial. This paper presents the results of a three-year study of the contextual determinants and dimensions of artisanal fishing community perceptions about climate change in coastal Bangladesh. Results of this study indicate that geographic characteristics, socio-economic status, worldviews, tradition, observations and disaster experiences are important determinants for shaping fishers’ perceptions about climate change. Fishers also demonstrate a long-standing tradition of risk adaptation strategies, but do not link them to climate change. We argue that these perceptions provide ideas for how to form appropriate climate responses at local levels not only in Bangladesh but other developing countries.     

Energy technology modelling of major carbon abatement options

The International Energy Agency Energy Technologies Perspectives (ETP) model is used to assess the prospects for carbon abatement options, including carbon capture and storage, up to 2050. Three main scenarios are considered: a Baseline scenario with current energy policies, an accelerated technology scenario that seeks to return energy-related CO₂ emissions in 2050 to their level in 2005, and a scenario for which CO₂ emissions are reduced at 50% of current levels by 2050. To reach these emissions reduction targets, annual global CO₂ emissions in the year 2050 must be reduced by 35 GtCO₂ to 48 GtCO₂ compared to the Baseline scenario. The analysis presented here shows that a broad portfolio of emissions reducing technologies will need to be deployed across all economic sectors of the global economy to reach these targets. Carbon dioxide capture and storage (CCS) is one of the suite of technologies employed across the globe to reach these targets. CCS adoption occurs in many aspects of the global economy and accounts for 14–19% of all emissions reductions. The total amount of CO₂ captured and stored in deep geologic reservoirs up to 2050 ranges between 5.1 GtCO₂ and 10.4 GtCO₂ in these two climate policy scenarios. Up to 2030, more than half of total CCS deployment takes place in OECD countries. After 2035, emerging economies account for more than half of total CCS use. This paper also demonstrates that as the climate policy becomes more stringent it will be necessary for CCS to deploy more extensively in many different industries outside of the electric power sector which often receives the most attention in discussions of CCS's role in addressing climate change.     

Perceptions of climate change in Thunder Bay,Ontario: towards a place-based understanding

Climate change is a global phenomenon that it is experienced and understood in places. This research examined the ways in which community members understand, perceive, and experience climate change in the context of Thunder Bay Ontario; a mid-size and remote city located in Northern Ontario, using semi-structured walking interviews (N?=?18). Themes that emerged from the interview data are presented and discussed in relation to the literature. Results emphasise that participants conceptualise climate change as a complex ethical issue that is caused by greenhouse gas emissions and a range of underlying social, economic, and political factors. Participants identified numerous changes in weather, seasonality, and extreme events and anticipate future impacts on local and regional food, water, and forests primarily. Emotional impacts of climate change, ranging from worry to feeling hopeful, emerged as an important theme. The data illustrate that the observed, experienced, and anticipated impacts of climate change are shaped by experiences on the land and water within the community of Thunder Bay and the region of Northern Ontario. Finally, the interview data illustrate that participants believe that transformative action, by a range of actors, is called for to address the problem of climate change. This study highlights the importance of place-based and context-specific climate change research and the utility of walking interviews.     

Changes in electrical generator cooling systems: Are they cost-effective sources of water now and under climate change?

In the United States, thermal power plant electrical generators (EGs) are large water diverters and consumptive users who need water for cooling. Retrofitting existing cooling systems to dry cooling and building new facilities with dry cooling can save water and reduce EG's vulnerability to drought. However, this can be an expensive source of water. We estimate that the cost of water saved by retrofitting cooling in existing EGs ranges from $0.04/m³ to $18/m³ depending on facility characteristics. Also water savings from building new EGs with dry cooling ranges in cost per unit water from $1.29/m³ to $2.24/m³. We compare costs with that for water development projects identified in the Texas State Water Plan. We find the water cost from converting to dry cooling is lower than many of the water development possibilities. We then estimate the impact of climate change on the cost of water saved, finding climate change can increase EG water use by up to 9.3% and lower the costs of water saved. Generally, it appears that water planners might consider cooling alterations as a cost competitive water development alternative whose cost would be further decreased by climate change.     

Water and economic development: The role of variability and a framework for resilience

The article advances the hypothesis that the seasonal and inter‐annual variability of rainfall is a significant and measurable factor in the economic development of nations. An analysis of global datasets reveals a statistically significant relationship between greater rainfall variability and lower per capita GDP. Having established this correlation, we construct a water resources development index that highlights areas that have the greatest need for storage infrastructure to mitigate the impacts of rainfall variability on water availability for food and basic livelihood. The countries with the most critical infrastructure needs according to this metric are among the poorest in the world, and the majority of them are located in Africa. The importance of securing water availability in these nations increases every day in light of current population growth, economic development, and climate change projections.     

Water Supply Reliability Tradeoffs between Removing Reservoir Storage and Improving Water Conveyance in California

Population growth, climate change, aging infrastructure, and changing societal values alter how water must be managed in the 21st Century. O'Shaughnessy Dam, located in Yosemite National Park, has been identified as a possible candidate for dam removal. It is a component of San Francisco's Hetch Hetchy System and is operated for water supply and hydropower. This article describes a spatially scaled approach to analyze water reliability without O'Shaughnessy Dam, but with improved water conveyance between the Hetch Hetchy System and existing reservoirs and aqueducts at the watershed, regional Bay Area, and statewide scales. It broadens previous research to highlight larger scale implications of removing O'Shaughnessy Dam and evaluates the role of improved water conveyance for water management. CALifornia Value Integrated Network, a large‐scale hydro‐economic model evaluates intertied water management using estimated urban and agricultural water demands for year 2050 with 72‐year historical and warm, dry hydrologic conditions. Results suggest that O'Shaughnessy Dam can be removed with additional conveyance at any spatial scale while maintaining water reliability. With a warm, dry climate, water reliability, and storage decline, indicating removing O'Shaughnessy Dam may have less effect on water management than climate change when conveyance is improved between the Hetch Hetchy System and nearby systems. Improving water conveyance can sometimes substitute for water storage in storage‐rich watersheds.     

Rice and Bricks: Environmental Issues and Mapping of the Unusual Crop Rotation Pattern in the Kathmandu Valley,Nepal

The Kathmandu Valley in Nepal has experienced a very rapid increase in population resulting in considerable land use/land cover change and also a series of environmental problems. One of the results of the population increase is an expansion of brick manufacturing within the Valley because most structures are brick. The brick kilns are intense in several locations of the Valley and have an interesting pattern of using the same lands for bricks during the dry season and then conversion to rice during the wet, summer monsoon months. The increase in brick production has contributed to environmental problems including decreased soil productivity, lowered ground water levels, and particularly air pollution. Brick manufacturing has little, if any, effective regulation. There is a lack of current, accurate data on brick production that could be resolved by remote sensing methods. Controls should be established and more information acquired on the location and impacts of brick production.