Table of Content.Sl.no.
How water and climate change interrelated? 3
Evidence if climate change impact on water and vice versa? 4-6
What are the mitigation and adaptation measures to combat the impact? 6-7
6. References 9-10
Climate is defined as weather averaged over an extended period of time (30-year intervals are typically used in establishing baseline climatology) Environment protection agency (2007). Earth’s history mentioned that, the climate has changed many times and has included ice ages and periods of warmth. Natural factors including volcanic eruptions, changing Earth’s orbit, and the amount of energy released from the sun were the primary factors affecting the Earth’s climate before the industrial revolutions. Conversely, human activities allied with the Industrial Revolution and burning fossil fuels began changing the composition of the atmosphere at beginning late in the 18th century. Climate change is the consequences of Global Warming caused due to gradual increase in the overall temperature of the earth’s atmosphere due to greenhouse effect caused by increased levels of CO2, CFCs and other pollutants. Human population densities are estimate to increase in portions of the region at the same time that climate is expected to be changing. Consequently, the effects of humans and climatic change are likely to affect water ecosystems within the region interactively (Moore et al., 1997).
Water is the primary medium through which climate change influences the Earth’s ecosystems and therefore people’s livelihoods and well-being. Climate change impacts related to water are already being experienced in some river basins resulting in severe and more frequent droughts and floods. Changes in precipitation, high average temperatures and other climatic variables are expected to affect the availability of water resources through changes in rainfall distributions, soil moisture, glaciers and ice/snow melt, and river and groundwater recharge and flows. These factors are probable to lead to further decline of water quality as well. The poor, who are the most vulnerable, are also likely to be affected the most (UN-Water, 2009).
How water and climate change interrelated?
Climate change and water processes are inextricably connected; actions in one area have impacts on the others. Better understanding of these complex and dynamic interrelationships are significant in addressing the increasing demand for fresh water, under the pressures of climate change. Climate change acts as a major driver of increasing temperature, loss of snowpack, and changing precipitation. It affects water resources resulting in
drought, flood, and deterioration of quantity, quality, and timing of water presents as well as increase water stress and having long-term impacts on the life cycles of water. Changes in temperature and precipitation patterns consequent to climate change are expected to affect the spatial and temporal distribution of water resources. Higher temperatures and lower precipitation would lead to reduced water supplies and increased water demands; this might cause worsening in the quality of water in freshwater bodies, exerting severe tension on the already fragile balance between supply and demand in many countries. (liu.2016)
With the increasing levels of greenhouse gases in the atmosphere, it is projected that there will be a steady rise in surface temperatures, both on land and in water. Coastal aquifers has been affected due to rising sea level, more over it have affected on major source of urban and regional water supply systems, and higher water temperatures and changes in extremes can worsen many forms of water pollution. Water supply consistency, health, agriculture, energy and aquatic ecosystems – all will feel the impact of these changes to the water cycle. The demand for water to meet these needs is also affected by climate change. The importance of water to sustainable social and economic development cannot be underestimated, yet many countries are already facing multiple water challenges, all of them compounded by climate change. (Raneesh, 2014).
Tropical storms and hurricanes are probable to become more severe, produce stronger peak winds, and produce increased rainfall over some areas due to warming sea surface temperatures (which can energize these storms) Owing to climate change, it lowers the levels of dissolved oxygen due to the inverse relationship that exists between dissolved oxygen and temperature as the temperature of the water increases, dissolved oxygen levels decrease hence many aquatic habitats will be negatively affected. Change in the plenty and spatial allocation of coastal and marine species and decline in populations of some species. Increased rates of evapotranspiration from waterbodies, resulting in reduction of some waterbodies such as the Great Lake are due to the rise in temperature. (EPA, 2007).What is the Evidence if climate change impact on water and vice versa?
Climate change had poses major threats to humans and ecosystems so the world has reached to stage to be concerned about climate change. The 2007 United Nations Climate Change Conference in Bali acknowledged that even the minimum predicted shifts in climate for the twenty-first century – more than twice the 0.6 °C increase that has occurred since 1900 – would be significant and disruptive (UN-Water, 2009).
Rise in temperature the water evaporation rate increases, and that increases the amount of water being held in the atmosphere. Because there is more atmospheric moisture, there are heavier downpours when it rains. Although moderate increases in annual average precipitation are projected, there is likely to be a wider disparity in the pattern of rainfall, specifically, drier dry periods punctuated by more intense rainfall. National Climatic Data Center (NCDC) show that total annual, average precipitation over the contiguous United States has increased at an average rate of 6.1 percent per century since 1900, although there was considerable regional variability. In Africa alone, between 75 million and 250 million people may be exposed to increased water stress by 2020 due to climate change. As a result of change in precipitation pattern water availability reduces in ground water, surface water and increase water demand due to limited supply moreover water quality get worsen due to increased runoff resulting in erosion and sedimentation and overwhelmed water infrastructure due to flooding.
Increase in storm intensity
Tropical storms and hurricanes are prone to become more extreme, produce stronger peak winds, produce increased rainfall, and cause larger storm surges because of warming sea surface temperatures (which can energize these storms). When there is high tropical storm intensities it will have negative effects on water resources. According to EPA (2007) more severe tropical storms can damage infrastructure, increases flooding, which can overwhelm water infrastructure, and cause pollutants to directly enter waterways and contaminate water supplies. Storms also create coastal erosions. In the Northeast, models predict coastal erosion, loss of wetland habitat, and increased risk of storm surges from sea level rise. In the Southeast, intense development within the coastal zone places coastal floodplains at risk for flooding from sea level rise, storm surges and extreme precipitation events. The Pacific Northwest could experience an increase in wave heights.
Rising in sea level
Sea levels are rising worldwide, Lagos, one of the largest city in the world and Africa is highly affected by sea-level rise, coastal erosion, saltwater intrusion and flooding. Lagos mega-city experienced severe coastal erosion which removed over 2 kilometers of the popular Lagos beach fronts shown by empirical evidence of sea level rise. The rock moles constructed between 1908 and 1912 to protect the natural Littoral Drifts at the Bar beach were continually washed away by the coastal surge, leading to an annual erosion rate of 25 to 30 meters.(Urama & Ozor,2010). In the United States, sea level has been rising 0.08 to 0.12 inches (2.0 to 3.0 mm) per year along most of the U.S. Atlantic and Gulf coasts. (EPA,2007). The global average sea level will rise by 7.2 to 23.6 inches (18-59 cm or 0.18-0.59m) by 2100 relative to 1980 to 1999 under a range of scenarios (IPCC, 2007c). Moreover melting of glacial due to increase in temperature also results in rising sea level.
Global warming consistently projects an increase in mean annual temperatures, predominantly in response to rising carbon dioxide levels. Stream temperature is strictly dependent on-air temperature, but is also influenced by some other factors, such as shading from riparian vegetation, watershed storage in wetlands, land cover, and groundwater connections (Fenoglio et al., 2010). Since temperature affects ectothermic species such as freshwater fishes, changes in water temperature, snowpack, and permafrost will have an important influence on the physiology, distribution, and survival of freshwater fishes, as well as other ecological processes in direct, indirect, and complex ways (Poesch, 2016).Average temperatures of US rose at an increased rate of 0.56 °F per decade from 1979 to 2005. The maximum temperature raise occurred in Alaska (3.3 °F per century). The Southeast experienced a very slight cooling trend over the entire period (-0.04 °F per century), but warming within this region has occurred since 1979. (EPA, 2007)
Fig.1 annual average global surface temperature Anomalies, 1880 -2006.http://cfpub.epa.gov/water rain/pdf/modules/climate- change-module-pdf
Water impact on climate change
From atmosphere Oceans naturally absorb CO2. When there is increase level of CO2 in atmosphere, oceans tends to absorb more of it. This process is called ocean acidification. The mixture of ocean water and the carbon dioxide forms carbonic acid. Carbonic acid reacts with carbonate ions (vital component to the structure of corals and the shells of marine organisms, such as calcifying phytoplankton that form the first level of the ocean food web in seawater). In other words, elevated levels of CO2 in the atmosphere leads to less of the building blocks that are needed to form the calcium carbonate skeletons of corals and other organisms that require calcium carbonate to make their shells. Due to ocean acidification potential marine food web breakdown, Coral, calcifying phytoplankton and zooplankton growth will be slowed Aquatic plants and animals that cannot tolerate increased salinity levels are lost. (EPA, 2007).Mitigation and adoption to combat impact
Mitigation measures can influence water resources and their management. Interventions of mitigation in the water system might be counter-productive to evaluate the impact cause by climate change.
Water Conservation: By choosing energy- and water-efficient options, businesses and individuals can conserve water resources and reduce the amount of greenhouse gases that are emitted. Water can be conserved by reducing the rate of pollution caused mainly due to the industrial wastes, proper dumping of non degradable substances. The UN Global Compact an initiative has worked since its beginning in 2000 to facilitate actions and partnerships that help companies become more sustainable and equitable. The UN Global Compact manages two sub-initiatives for business engagement (The CEO Water Mandate and Caring for Climate) focusing on water and climate, respectively. (United nation Global compact, n.d)
Energy Generation at Water Facilities: Wastewater treatment facilities have opportunities to generate energy. For example, some facilities can capture methane and burn it to generate electricity. Drinking water and wastewater treatment facilities have the potential to achieve 15–30 percent energy savings by implementing energy conservation measures alone, and even more with on-site energy generation.
Protect Underground Sources of Drinking Water from Geologic Carbon Sequestration: Geologic confiscation is method that effectual in reducing CO2 emissions to the atmosphere and stabilizing atmospheric concentrations of CO2.The Underground Injection Control Program control injection of fluids, including solids, semi-solids, liquids and gases (such as CO2) to protect underground sources of drinking water. UIC mainly tackle with construction, operation and closure of wells that inject a wide variety of fluids, including those that are considered commodities or wastes. (Woodward, Perkins, & Brown, 2010).Increase Green infrastructure and Low Impact Development: Green infrastructure uses products, technologies and practices that use natural systems that imitate natural processes to enhance overall environmental quality and provide utility services. As a wide-ranging key, green infrastructure techniques use soils and vegetation to infiltrate evapotranspirate or recycle storm water runoff. Reducing storm water runoff through the use of green infrastructure promotes the following: Ground water is naturally revived, combined sewer overflow events are reduced, vegetation does not require to be watered as frequently and excessive storm water is minimized and kept out of local waterways.
Adaptation for climate change
There has to be balance between mitigation and adaption to combat global climate change impact on water. Adaptation measures must be taken in several crucial fields such as food, energy, the environment and economic development.
Adaptation such as expansion of rain-water storage and water conservation practices can have profound consequences on water supply and demand. The storage of rain water can help in emergencies as well as it will help in wastage of water.
To suit the growing global populations the challenges has been increased in terms of producing enough food and commodities. Another challenge includes sharing scarce water and land with other growing use sectors, and acknowledging the ecological and environmental need for water supply. Thus, use of water is also being managed increasingly by equity and efficiency criteria. In short, major reforms and changes in farmer behavior are called for. (Climate change and water, 2009).
Technological improvements have been introduced in order to adapt with the consequences of climate impact on water. For example, technological innovation has been initiated in the field of agriculture like water flow control, storage management within surface irrigation systems on all scales storage, reuse, and precision application and localized irrigation, multiple-use systems in rural areas and urban agriculture with wastewater. (Richard et al.,n.d)
People have been adapting with climate change impact on water by coming out with various innovation such as getting water from another source with the help of pipelines moreover in severe case where there is no water availability people tends to migrate to the place where there is available of water.
Climate change is expected to worsen current stresses on water resources resulting from population enlargement, economic factors and land use changes, including urbanization. In recent times due to the losses of glaciers, reduction in snow cover, are likely to accelerate throughout the 21st century sinking water availability, hydropower potential, and changing seasonality. (Raneesh, 2014).There is also high confidence in the projection that many semi-arid areas will suffer a reduction in water resources due to climate change. Drought-affected areas are likely to increase in extent, with the potential for adverse impacts on multiple sectors, including agriculture, water supply, energy production and health. Waters are particularly vulnerable to climate change because many species within these fragmented habitats have limited abilities to disperse as the environment changes, water temperature and availability are climate-dependent and many systems are already exposed to numerous anthropogenic stressors. The different components of climate change (e.g. temperature, hydrology and atmospheric composition) not only affect multiple levels of biological organization, but they may also interact with the many other stressors to which fresh waters are exposed, and future research needs to address these potentially important synergies (Woodward, Perkins, & Brown, 2010).
Higher temperature rates tied with reduced precipitation, will lead to the continued lowering of water tables and many of the remaining wetlands in the region will be endangered, increasing losses already experienced from drainage works during the 19th and 20th centuries. Adaptive measures are required that are both ecologically and economically effective and capable of practical implementation at the local scale.
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