Introduction
While the effects of climate change are expected to be diverse and widespread, the fate of water deserves special attention because the survival of communities — and countries — is at risk.
Long-term climate change, as predicted and observed, is now the most pressing international issue of the twenty-first century.
Climate change will affect the availability, quality, and quantity of water required for basic human needs, undermining billions of people’s enjoyment of their basic rights to safe drinking water and sanitation.
Greenhouse gases
Greenhouse gases operate as a thermal blanket for the globe, absorbing heat and warming the earth’s surface.
Water vapor, carbon dioxide, nitrous oxide and methane make up the atmosphere.
Too much carbon dioxide (CO2) and other greenhouse gases in the atmosphere increase the greenhouse effect, causing the world to overheat.
Indeed, human actions such as the use of fossil fuels such as coal and oil have increased the amount of carbon dioxide CO2 in the atmosphere.
Increased levels of greenhouse gases and carbon dioxide emissions induce an increase in global temperature.
Temperature rises are seen as clear proof of climate change, and they have already begun to have major effects on water resources.
How does climate change affect water resources?
The temperature rises, changes in rainfall patterns and snowpack, and a boom withinside the frequency of flooding and droughts are the important things that weather alternate outcomes on water supplies.
Higher evaporation rates, a higher percentage of precipitation falling as rain rather than snow, earlier and shorter runoff seasons, multiplied water temperatures and decreased water first-rate in both inland and coastal regions are all effects of global weather change that have significant implications for water resources.
Summer will see the largest deficits, ensuing in decreased soil moisture stages and extra common and intense agricultural dryness.
Climate alternate will bring about extra common and intense droughts, for you to have substantial control effects for water useful resource users.
Droughts and floods are becoming increasingly severe as a result of climate change.
One of the key causes of this concern is rising global temperatures.
Climate change influences the water cycle because it changes when, where, and how much rain falls.
Over time, it also contributes to more severe weather occurrences.
As global temperatures rise, more water vaporizes, resulting in increased quantities of atmospheric water vapor and more frequent, heavy and severe rains in the future years.
Climate experts predict that when more waterfalls than plants and soil can absorb, more floods will occur.
The disturbance of the hydrological cycle is the primary effect of climate change on the world’s water supplies.
As a result of the increase in temperature, the increases, precipitation regime, and intensity changes, evaporation from the earth’s surface increases, snow cover decreases and glaciers melt.
Climate change’s effects on water supplies have ramifications across the economy.
Climate change causes the upper ocean to expand, rising sea levels and allowing salt water to invade freshwater horizons, diminishing the quantity and quality of their reserves.
Saltwater flow up river mouths harms fishing, impedes the functioning of water intakes, and threatens agriculture by producing soil salinization.
Rising sea levels may worsen occurrences such as floods, erosion and other dangers in the coastal zone, endangering essential infrastructure and populations.
Melting glaciers and snow cover as a result of rising temperatures reduces water resources, limiting water availability during hot and dry times in locations fed by mountain meltwater.
Over the past decade, the volume of the Himalayan glaciers has decreased by two-thirds, while the glaciers in the Andes have almost disappeared.
Thawing of permafrost leads to an increase in landslides and thereby poses a threat to infrastructure in permafrost regions.
Managing Water Resources
Predictions of climate change, while unreliable, provide insight into future water resource consequences and issues.
Increased temperatures and evaporation rates are predicted, as well as increasing proportions of winter precipitation coming as rain rather than snow, earlier and more severe summer dryness, and lower water quality.
Because of these effects, water shortages, which already result in significant economic losses, may become more widespread in many locations.
Economic losses in a variety of industries, from agriculture to energy and recreation, have a significant impact on local communities.
More periodic droughts mean higher societal costs, while water consumers’ adaptability will offset some of these costs.
Water users can utilize a variety of measures to mitigate the negative consequences of water shortages.
These include changing water rates to encourage conservation and the growth of water supply infrastructure, updating water storage and release plans for reservoirs, adopting crops and cropping methods that are resilient across a broader range of water availability, and extending and altering crop insurance programs (such as the Multi-Peril Crop Insurance Program’s Prevented Planting Provision), and promoting water transfer possibilities.
Drought-related wildfire damage can be reduced by employing long-range soil moisture predictions to pre-position fire suppression resources and, in the long run, by altering land-use restrictions to prevent growth in regions where fire risk is higher.
Inaccurate regional climate change models and long-term weather forecasts are limiting our capacity to foresee and properly plan for future water resource management difficulties.
Uncertainty about future climatic conditions makes it more difficult to plan for and respond to changes in the quantity and quality of water resources.
Trying to plan adequately for water scarcity when you don’t know when it will happen, how severe it will be, or how long it will last, for example.
It may be tempting to establish management plans based on the worst-case scenario; but, if the worst-case scenario does not materialize, the opportunity cost of this “safety-first” strategy might be significant.
The extent of economic losses linked to water resource shortages grows as more information becomes available.
Improvements in climate predictions and long-term weather forecasts, such as forecasts based on the El Nio-Southern Oscillation (ENSO), have the potential to reduce (or increase) economic losses (or benefits) connected with climate change.
Improved capacity to detect water shortages sooner, more precisely anticipate their location, intensity, and duration, and utilize such forecasts to influence management plans will boost water users’ trust in regional forecasts and their ability to efficiently prepare for and adjust to future water resource management difficulties.
Health consequences, biodiversity danger
Similarly, rising water temperatures and a decrease in dissolved oxygen will have an impact on water quality, reducing freshwater basins’ ability to self-purify.
Humans will observe greater hazards of water pollution and pathogen contamination as a result of floods or higher pollutant concentrations during droughts.
In addition to the impact on food production, the effects on physical and mental health, as a result of disease, injury, financial loss, and population displacement, are likely to be significant.
Many ecosystems, particularly forests and wetlands, are also affected, endangering biodiversity.
Water supplies will be impacted not only by agriculture (which accounts for 69% of freshwater withdrawals), but also by industry, energy production, and even fisheries.
Climate change caused by wastewater
Wastewater treatment contributes to climate change by emitting GHGs, accounting for an estimated 3% to 7% of total emissions.
These emissions are caused by the energy necessary for wastewater treatment as well as the biological processes employed.
Untreated wastewater, however, is a major source of methane, a potent greenhouse gas, due to the decomposition of the organic stuff it contains.
According to the research, wastewater contains more energy than is required for treatment, assuming that it is harvested.
It is believed that between 80 and 90 percent of wastewater worldwide is released into the environment without treatment.
In practice, optimum water resource management involves engaging in contemporary treatment techniques that enable the extraction of methane from organic waste and then using this biogas to provide the energy required to power the process, as is already done in water-scarce countries.
These strategies have enabled the public utilities involved to reduce CO2 emissions by thousands of tonnes while saving money and increasing service quality.
Adaptation and mitigation can be recommended options
Adaptation is a combination of natural, physical and technological possibilities, as well as social and institutional approaches, to prevent damage and capitalize on the few beneficial effects of climate change.
It is expected to have immediate benefits, mostly at the local level.
Mitigation refers to the human actions required to minimize greenhouse gas emissions while utilizing carbon sinks to reduce the quantity of CO2 and other GHGs in the atmosphere.
It might cover enormous geographical areas, yet the benefits can last for decades.
However, the opportunities for mitigation in water management are virtually untapped.
References
[1] How Climate Change Impacts Water Access (online) available at: https://www.nationalgeographic.org/article/how-climate-change-impacts-water-access/
[2] Effects of Climate Change on Water Resources, 23 Jan (online) available at: https://www.choicesmagazine.org/2008-1/theme/2008-1-04.htm
[3] Impact of Climate Change on Water Resources, 1 May (online) available at: https://www.watercom/doc/impact-of-climate-change-on-water-resources-0001
[4] Water resources an essential part of the solution to climate change (online) available at: https://www.waterworld.com/drinking-water/potable-water-quality/article/14170004/water-resources-an-essential-part-of-the-solution-to-climate-change
